docs(kms): correct the describe_key cache divergence bound

docs(kms): state that no request field sets the cache metrics switch
docs(kms): document the landed KMS metric families and narrow the gaps list
2026-08-01 19:12:14 +00:00 · 2026-08-02 03:11:33 +08:00 · 2026-08-02 03:09:11 +08:00 · 2026-08-02 03:08:17 +08:00 · 2026-08-02 03:05:25 +08:00 · 2026-08-01 17:31:50 +00:00
352 changed files with 57475 additions and 6110 deletions
@@ -1,19 +1,21 @@
 ---
 name: rustfs-release-publish
-description: "End-to-end RustFS release pipeline: bump version files on main directly to the final target version, cut a preview tag on that commit, verify the CI build and release artifacts, run the downloaded binary locally and exercise the console, validate the server with the latest rc client, then publish the final tag on the SAME validated commit — never a new bump commit, never latest main. Use whenever the user wants to release/publish a RustFS version (发版/发布)."
+description: "End-to-end RustFS release pipeline: first publish any merged-but-unreleased rustfs/console changes and wait for its latest Release asset, then bump RustFS version files on main directly to the final target, publish a visible GitHub prerelease from a preview tag without updating latest channels, validate it, and publish the final tag on the SAME commit. Use whenever the user wants to release/publish a RustFS version (发版/发布)."
 ---
 # RustFS Release Publish (preview-validated pipeline)

 This skill orchestrates a full release. It wraps `rustfs-release-version-bump` (which only edits version files and opens the PR) with a mandatory preview-tag validation loop before the final tag is published.

-Core design: **version files never carry a `-preview.N` suffix**. The preview suffix exists only in tag names. This works because the binary self-reports the git tag it was built from (`build::TAG` via shadow_rs, see `rustfs/src/config/cli.rs` `SHORT_VERSION`), and `build.yml` derives artifact names and prerelease classification from the tag name — Cargo.toml's version is only a no-tag fallback. Therefore the preview tag and the final tag can (and MUST) point at the exact same commit: what you validated is byte-for-byte the source that ships.
+Core design: **version files never carry a `-preview.N` suffix**. The preview suffix exists only in tag names. A preview tag creates a visible GitHub Release marked Prerelease and uploads versioned assets, but it never becomes GitHub Latest and never updates `*-latest`, `latest.json`, R2, Docker, or Helm channels. This works because the binary self-reports the git tag it was built from (`build::TAG` via shadow_rs, see `rustfs/src/config/cli.rs` `SHORT_VERSION`), and `build.yml` derives artifact names and preview classification from the tag name — Cargo.toml's version is only a no-tag fallback. Therefore the preview tag and the final tag can (and MUST) point at the exact same commit: what you validated is byte-for-byte the source that ships.

 Pipeline shape:

 ```
-bump version files to <target> (final version, ONE commit) -> merge
+check console main against its latest Release
+  -> if ahead: publish console -> wait for Release asset + latest API
+  -> bump RustFS version files to <target> (final version, ONE commit) -> merge
  -> tag <preview-tag> at that commit -> CI green
-  -> verify release artifacts -> run binary locally + console checks
+  -> verify preview Release assets -> run binary locally + console checks
  -> validate with latest rc client
  -> tag <target> at the SAME commit (zero delta) -> re-verify CI/release
 ```
@@ -23,7 +25,7 @@ On validation failure: fix lands on main via normal PR (version files are alread
 ## Required inputs

 - Final target version, for example `1.0.0-beta.10`.
- Preview iteration `N` (default: next unused preview tag for that target; check with `git tag -l '<target>-preview.*'` — and for stable targets `git tag -l '<target>-rc.*'` — after `git fetch --tags`).
+- Preview iteration `N` (default: next unused preview tag for that target; check with `git tag -l '<target>-preview.*'` after `git fetch --tags`).

 If the target version is missing or ambiguous, stop and ask before doing anything (see the semver gate below).

@@ -45,14 +47,18 @@ Rules:

 ## Preview tag naming

- Prerelease target (contains `alpha`/`beta`/`rc`): preview tag is `<target>-preview.N`, e.g. `1.0.0-beta.10-preview.3`. It contains `beta`, so `build.yml`'s substring-based classification marks it prerelease — safe.
- **Stable** target (e.g. `1.1.0`): NEVER tag `1.1.0-preview.N` — `build.yml` marks a tag prerelease only if its name contains `alpha`, `beta`, or `rc`, so `1.1.0-preview.N` would be treated as a stable release and overwrite `latest.json` as stable. Use `1.1.0-rc.N` as the preview tag instead.
+- Use `<target>-preview.N` for every target, e.g. `1.0.0-beta.10-preview.3` or `1.1.0-preview.1`.
+- The canonical suffix is exactly `-preview.<digits>`. `build.yml` recognizes it before alpha/beta/rc classification and routes it to the preview-only path; any other tag containing `-preview` fails closed instead of being treated as a release.
+- A preview Release MUST be published with `isPrerelease=true` and `isLatest=false`. Any `*-latest` preview asset or preview-triggered `latest.json`, R2, Docker, or Helm publication is a pipeline failure.

 ## Hard rules

 - Version files (Cargo.toml, Cargo.lock, README, flake.nix, Chart.yaml, rustfs.spec) are bumped ONCE, directly to `<target>`. Never write a `-preview.N` suffix into any version file. If `rustfs-release-version-bump` is ever asked for a `-preview` version, that is a pipeline bug — stop.
+- Preview Release assets are versioned and intentionally visible on the Releases page. Do not label them Latest or use them to update any latest distribution channel.
 - Tags have no `v` prefix. Always annotated: `git tag -a <tag> -m "Release <tag>"`.
 - The final tag MUST point at exactly `PREVIEW_HASH` — the commit the validated preview tag points at. Never tag current `main` HEAD (commits merged after validation are unvalidated), and never create an extra version-bump commit between preview and final.
+- When a previous deliverable exists, GitHub Release notes for the preview and final tags MUST use it as their shared comparison baseline: the most recently published non-preview Release before the target. Internal `-preview.N` Releases are explicitly excluded from that selection, even when they point at the same commit as the final tag. If no previous deliverable exists, omit `previous_tag_name` and record that GitHub's default baseline fallback was used.
+- Generated Release notes carry a workflow-management marker so retries can repair them. Before manually curating a generated body, remove that marker; unmarked non-placeholder notes are preserved by later workflow runs.
 - Phases run in order; a failure in any phase blocks everything after it. After the fix lands on main, restart from Phase 2 with the next preview iteration against the new `origin/main` hash — do not resume mid-pipeline against a stale hash.
 - If the release is abandoned after Phase 1 merged, main's version files claim a version that was never tagged. Either revert the bump PR or leave it to be overwritten by the next release — but tell the user explicitly and record the decision.
 - User-facing status updates in Chinese; commits, PR titles/bodies, and tag messages in English. No hard-wrapping in commit messages, PR bodies, or documentation prose — one logical line per sentence/paragraph, let soft wrap handle display.
@@ -63,6 +69,61 @@ Rules:
 - `gh auth status` works; confirm you can view `gh release list -L 3`.
 - Confirm the exact final target version with the user if not explicit.

+### Console release gate
+
+Complete this gate before changing any RustFS version file or creating any RustFS tag. RustFS `build.yml` downloads the asset returned by `repos/rustfs/console/releases/latest`, so a successful Console build alone is insufficient.
+
+1. Read the latest published Console tag and compare it with Console `main`:
+
+```bash
+CONSOLE_REPO="rustfs/console"
+CONSOLE_LATEST=$(gh api "repos/${CONSOLE_REPO}/releases/latest" --jq .tag_name)
+gh api "repos/${CONSOLE_REPO}/compare/${CONSOLE_LATEST}...main" \
+  --jq '{status, ahead_by, behind_by, commits: [.commits[] | {sha, message: .commit.message}]}'
+```
+
+- `ahead_by == 0`: no merged Console change is waiting for release. Still verify the current latest asset using step 4, then continue to Phase 1.
+- `ahead_by > 0` and `behind_by == 0`: publish Console before continuing. Report the merged commits and select the next unused `vX.Y.Z` tag. Default to the next patch version when the changes are fixes or backward-compatible UI work; stop for confirmation if a minor/major bump is plausible.
+- Any diverged history or `behind_by > 0`: stop and resolve the Console release baseline explicitly. Do not guess a range or publish RustFS.
+
+2. Clone/fetch `rustfs/console` into a scratch directory and record its exact `main` commit. Before creating a tag, check for a `v*` tag or Release workflow already associated with that hash. If one is in progress, wait for it instead of creating another version:
+
+```bash
+CONSOLE_SCRATCH=$(mktemp -d)
+gh repo clone "$CONSOLE_REPO" "$CONSOLE_SCRATCH/console"
+git -C "$CONSOLE_SCRATCH/console" fetch origin main --tags
+CONSOLE_HASH=$(git -C "$CONSOLE_SCRATCH/console" rev-parse origin/main)
+git -C "$CONSOLE_SCRATCH/console" tag --points-at "$CONSOLE_HASH" 'v*'
+gh run list -R "$CONSOLE_REPO" --workflow release.yml --commit "$CONSOLE_HASH" --limit 5
+```
+
+If no release exists or is running for `CONSOLE_HASH`, create the selected annotated tag at that exact hash and push it:
+
+```bash
+git -C "$CONSOLE_SCRATCH/console" tag -a "<console-tag>" -m "Release <console-tag>" "$CONSOLE_HASH"
+git -C "$CONSOLE_SCRATCH/console" push origin "<console-tag>"
+```
+
+Console tags include the `v` prefix. Pushing the tag triggers `.github/workflows/release.yml` (`🚀 Release`). Remove `CONSOLE_SCRATCH` after the gate completes.
+
+3. Find the exact tag run and wait for completion:
+
+```bash
+gh run list -R "$CONSOLE_REPO" --workflow release.yml --branch "<console-tag>" --limit 1
+gh run watch -R "$CONSOLE_REPO" "<console-run-id>" --exit-status
+```
+
+4. Block until the published Release is non-draft, the latest endpoint returns the expected tag, and `rustfs-console-<console-tag>.zip` is uploaded, non-empty, and carries a `sha256:` digest:
+
+```bash
+gh release view -R "$CONSOLE_REPO" "<console-tag>" --json isDraft,isPrerelease,assets,url
+test "$(gh api "repos/${CONSOLE_REPO}/releases/latest" --jq .tag_name)" = "<console-tag>"
+test "$(gh api "repos/${CONSOLE_REPO}/releases/tags/<console-tag>" \
+  --jq '[.assets[] | select(.name == "rustfs-console-<console-tag>.zip" and .state == "uploaded" and .size > 0 and (.digest | startswith("sha256:")))] | length')" -eq 1
+```
+
+Treat a missing/mismatched asset, digest, latest tag, or failed/cancelled workflow as BLOCKED. Do not start Phase 1 until the Console gate passes. Record `CONSOLE_TAG`, `CONSOLE_HASH`, Console run URL, and Release URL for the final report.
+
 ## Phase 1 — Version bump to the final target (once)

 - If main's version files already read `<target>` (e.g. this is a restart after a failed preview), verify with `rg -n "<target>" Cargo.toml rustfs.spec helm/rustfs/Chart.yaml` and skip to Phase 2.
@@ -85,16 +146,17 @@ git push origin "<preview-tag>"

 Pushing the tag triggers `.github/workflows/build.yml` ("Build and Release"); `docker.yml` chains off it via `workflow_run`.

+The preview run builds versioned artifacts and publishes them in a GitHub prerelease. Its latest-channel, R2, Docker, and Helm jobs must be skipped. Those publication paths run only after the final tag is pushed.
+
 On a restart (N+1), refresh `PREVIEW_HASH=$(git rev-parse origin/main)` first — it must contain the fix — and re-report it.

-## Phase 3 — CI and artifact verification
+## Phase 3 — CI and preview Release verification

- Watch the tag build: `gh run list --workflow build.yml --limit 5` then `gh run watch <run-id>`. Every matrix target must succeed (linux x86_64/aarch64 × musl/gnu, macos-aarch64, windows-x86_64) plus the release and latest.json jobs.
- Verify the GitHub release: `gh release view "<preview-tag>" --json isPrerelease,assets`
-  - `isPrerelease` must be `true`.
-  - Assets must include all 6 platform zips in both versioned (`rustfs-<platform>-v<tag>.zip`) and `-latest` forms, plus `SHA256SUMS`, `SHA512SUMS`, `rustfs-<tag>.sbom.cdx.json`, `rustfs-<tag>.provenance.json`.
- Verify the chained Docker run succeeded: `gh run list --workflow docker.yml --limit 3`.
- Checksum spot-check for the platform you will run locally: download the zip and `SHA256SUMS`, verify with `shasum -a 256 -c` (grep to one line).
+- Find and watch the tag build: `gh run list --workflow build.yml --branch "<preview-tag>" --limit 1` then `gh run watch <run-id>`. Every build matrix target must succeed (linux x86_64/aarch64 × musl/gnu, macos-aarch64, windows-x86_64).
+- Confirm the Release publication jobs (`create-release`, `upload-release-assets`, and `publish-release`) succeed while `update-latest-version` is skipped.
+- Verify `gh release view "<preview-tag>" --json isPrerelease,assets,url`: `isPrerelease` must be `true`, and the Release must contain all 6 versioned platform zips, checksums, SBOM, and provenance with no `-latest` assets. Confirm `gh api repos/{owner}/{repo}/releases/latest --jq .tag_name` does not return `<preview-tag>`.
+- Record `PREVIOUS_DELIVERABLE`, selected from published Releases by `publishedAt` after excluding the current tag and every `-preview.N` tag. Verify `gh release view "<preview-tag>" --json body --jq .body` contains `## What's Changed` and, when `PREVIOUS_DELIVERABLE` exists, `**Full Changelog**: https://github.com/rustfs/rustfs/compare/<PREVIOUS_DELIVERABLE>...<preview-tag>`. For a repository with no previous deliverable, verify a Full Changelog link exists and record the GitHub baseline fallback.
+- Confirm preview-triggered Docker and Helm jobs are skipped. Preview validation covers the built RustFS binaries, embedded console, and rc compatibility; Docker image construction and Helm publication are deferred to the final tag because the Dockerfiles consume GitHub Release assets.

 ## Phase 4 — Run the artifact locally, verify the console

@@ -157,13 +219,15 @@ git push origin "<target>"
 ```

 - CI rebuilds from the same source; the only changed input is the tag name, so the binary now self-reports `<target>`.
- Re-run the Phase 3 verification against the final tag: all matrix jobs green; `gh release view "<target>"` shows the full asset set; for a prerelease target `isPrerelease` is `true`, for a stable target it must be `false` and `latest.json` must be updated.
+- Verify the final tag's complete publication path: all matrix and release jobs green; `gh release view "<target>"` shows the full versioned and `-latest` asset set plus checksums, SBOM, and provenance; Docker and Helm workflows succeed; `latest.json` points to `<target>`. A stable target must have `isPrerelease=false` and `isLatest=true`. An alpha/beta/rc target must have `isPrerelease=true`; GitHub does not permit prereleases to be Latest, but the project `latest.json` still advances to the final non-preview target.
+- Verify the final Release body contains `## What's Changed` and a Full Changelog link. When `PREVIOUS_DELIVERABLE` exists, the link MUST be `https://github.com/rustfs/rustfs/compare/<PREVIOUS_DELIVERABLE>...<target>` and the baseline MUST equal the preview Release baseline; for example, both `1.0.0-beta.12-preview.1` and `1.0.0-beta.12` compare from `1.0.0-beta.11`.
 - Optionally spot-check `./rustfs --version` from a final-tag artifact — it must report `<target>`.

 ## Output contract

 Always report:

+- Console gate result: previous/latest Console tags, whether merged changes required a release, `CONSOLE_HASH`, and Console run/Release URLs when a release was published.
 - Target version, preview tag(s) used, `PREVIEW_HASH` (which both tags point at).
- Per-phase result (PASS/FAIL/BLOCKED) with key evidence: CI run URLs, release URLs, console check results, the rc command matrix.
+- Per-phase result (PASS/FAIL/BLOCKED) with key evidence: preview and final Release URLs, preview `isPrerelease`/`isLatest` state, final latest-channel state, console check results, and the rc command matrix.
 - Any deviation from this pipeline and why the user approved it.
@@ -18,7 +18,7 @@ Validated baseline: release pattern used in PR `#2957`.

 If target version is missing or ambiguous, stop and ask before editing.

-Reject any target version containing a `-preview.` suffix: preview identifiers are tag-only (see `rustfs-release-publish`) and must never be written into version files. If asked for one, stop and point to the release pipeline instead of editing.
+Reject any target version containing `-preview`: preview identifiers are tag-only (see `rustfs-release-publish`) and must never be written into version files. If asked for one, stop and point to the release pipeline instead of editing.

 ## Read before editing

@@ -28,6 +28,8 @@ script-tests: ## Run shell script tests
 	./scripts/test_entrypoint_credentials.sh
 	./scripts/test_internode_grpc_ab_bench.sh
 	./scripts/test_object_batch_bench_enhanced.sh
+	./scripts/test_hotpath_warp_ab_gate.sh
+	./scripts/test_hotpath_warp_abba.sh
 	./scripts/test_exact_1mib_handoff_abba.sh
 	./scripts/test_pinned_paired_abba_bench.sh
 	./scripts/test_manual_transition_runbooks.sh
@@ -300,9 +300,6 @@ path = "junit.xml"
 # negative-path siblings of each family stay in as regression guards.
 #   * rustfs#4843 — over-limit archive entry paths hard-reject the whole
 #     archive even under ignore-errors semantics.
-#   * rustfs#4846 — distributed-lock quorum tests misclassify as timeout
-#     under parallel load (multi-node in-process clusters; natural home is
-#     ci-7's nightly cluster lane).
 [profile.e2e-full]
 default-filter = """
    package(e2e_test)
@@ -311,7 +308,6 @@ default-filter = """
    & !test(/^replication_extension_test::/)
    & !test(/^multipart_auth_test::test_signed_put_object_extract_skips_invalid_entry_when_ignore_errors_enabled$/)
    & !test(/^snowball_auto_extract_test::tests::snowball_auto_extract_(ignores_invalid_entries_when_requested|supports_standard_headers_with_combined_extract_options)$/)
-    & !test(/^reliant::lock::test_distributed_lock_(2_nodes_grpc_read_survives_failed_node|4_nodes_grpc_read_write_quorum_split_with_two_failed_nodes)$/)
 """
 fail-fast = false

@@ -60,6 +60,16 @@ The file `prometheus-rules/rustfs-get-optimization-alerts.yaml` contains pre-con
 | `CodecStreamingFallbackSpike` | Warning | Codec streaming fallback > 10x baseline for 10m |
 | `IoQueueSaturation` | Warning | IO queue utilization > 90% for 5m |

+The file `prometheus-rules/rustfs-kms-alerts.yml` contains alerting rules for the KMS backend operation metrics. Thresholds are conservative defaults pending staging baseline calibration; response procedures live in `docs/operations/kms-observability-runbook.md`, and the matching dashboard is `deploy/observability/grafana/rustfs-kms-observability.json`.
+
+| Alert | Severity | Condition |
+|-------|----------|-----------|
+| `KmsBackendFatalErrors` | Critical | Fatal (non-retryable) attempt failures > 0 for 5m |
+| `KmsBackendHighErrorRate` | Critical | Non-success operation ratio > 5% for 10m (with traffic guard) |
+| `KmsBackendP99LatencyHigh` | Warning | Operation p99 duration (incl. retries) > 2s for 10m |
+| `KmsBackendAttemptFailureSpike` | Warning | Attempt failure rate > 0.5/s for 10m |
+| `KmsBackendRetryBudgetExhausted` | Warning | budget_exhausted / deadline_exceeded outcomes > 0.05/s for 10m |
+
 ### Enabling Alert Rules

 Add the alert rules file to your Prometheus configuration:
@@ -60,6 +60,16 @@
 | `CodecStreamingFallbackSpike` | 警告 | Codec streaming 回退 > 10x 基线，持续 10 分钟 |
 | `IoQueueSaturation` | 警告 | IO 队列利用率 > 90%，持续 5 分钟 |

+文件 `prometheus-rules/rustfs-kms-alerts.yml` 包含 KMS 后端操作指标的告警规则。阈值为保守默认值，待 staging 基线校准；响应流程见 `docs/operations/kms-observability-runbook.md`，配套仪表盘为 `deploy/observability/grafana/rustfs-kms-observability.json`。
+
+| 告警 | 级别 | 条件 |
+|------|------|------|
+| `KmsBackendFatalErrors` | 严重 | fatal（不可重试）尝试失败 > 0，持续 5 分钟 |
+| `KmsBackendHighErrorRate` | 严重 | 非 success 操作占比 > 5%，持续 10 分钟（含流量下限保护） |
+| `KmsBackendP99LatencyHigh` | 警告 | 操作 p99 耗时（含重试）> 2s，持续 10 分钟 |
+| `KmsBackendAttemptFailureSpike` | 警告 | 尝试失败率 > 0.5/s，持续 10 分钟 |
+| `KmsBackendRetryBudgetExhausted` | 警告 | budget_exhausted / deadline_exceeded 结果 > 0.05/s，持续 10 分钟 |
+
 ### 启用告警规则

 在 Prometheus 配置中添加告警规则文件：
@@ -0,0 +1,188 @@
+# Copyright 2024 RustFS Team
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# =============================================================================
+# RustFS KMS backend — Prometheus alerting rules
+# =============================================================================
+#
+# Metric source: the KMS operation-policy choke point in
+# crates/kms/src/policy.rs. All label values are static enum strings
+# (operation, op_class, outcome, error_class); key identifiers, key material,
+# and tokens never appear in labels.
+#
+# Response procedures: docs/operations/kms-observability-runbook.md
+#
+# IMPORTANT — threshold status: every numeric threshold below is a
+# conservative default chosen without a production baseline. Calibrate against
+# a staging baseline before relying on these alerts for paging, and prefer
+# loosening over tightening until the baseline exists. Formal SLO targets are
+# deliberately not encoded here (see rustfs/backlog#1584).
+#
+# NOTE: prometheus.yml loads /etc/prometheus/rules/*.yml — keep the .yml
+# extension or the file is silently ignored by the docker-compose stack.
+#
+# Validate: promtool check rules rustfs-kms-alerts.yml
+# =============================================================================
+
+groups:
+  # ==========================================================================
+  # Critical alerts — immediate action required
+  # ==========================================================================
+  - name: rustfs-kms-critical
+    interval: 30s
+    rules:
+      # ------------------------------------------------------------------
+      # 1. KmsBackendFatalErrors
+      #    Any attempt failure classified as fatal (non-retryable): auth
+      #    or permission errors, malformed requests, missing keys. The
+      #    policy never retries these, so even a low rate means real
+      #    operations are failing right now.
+      # ------------------------------------------------------------------
+      - alert: KmsBackendFatalErrors
+        expr: |
+          sum by (operation) (rate(rustfs_kms_backend_attempt_failures_total{error_class="fatal"}[5m])) > 0
+        for: 5m
+        labels:
+          severity: critical
+          component: kms
+        annotations:
+          summary: "KMS backend fatal errors on operation {{ $labels.operation }}"
+          description: >-
+            Attempt failures classified as fatal are occurring at
+            {{ $value | printf "%.3f" }}/s on operation
+            {{ $labels.operation }}. Fatal failures are not retried:
+            each one is a KMS backend call that failed permanently
+            (authentication, permissions, malformed request, or a
+            missing key/version).
+          runbook_url: "https://github.com/rustfs/rustfs/blob/main/docs/operations/kms-observability-runbook.md#kmsbackendfatalerrors"
+
+      # ------------------------------------------------------------------
+      # 2. KmsBackendHighErrorRate
+      #    Sustained share of operations terminating without success
+      #    (fatal, budget_exhausted, deadline_exceeded). The cancelled
+      #    outcome is excluded because shutdowns legitimately produce it.
+      #    The traffic guard keeps a single failure on a near-idle
+      #    cluster from firing the alert.
+      #    Threshold: 5% for 10m — conservative default, calibrate
+      #    against a staging baseline.
+      # ------------------------------------------------------------------
+      - alert: KmsBackendHighErrorRate
+        expr: |
+          (
+            sum(rate(rustfs_kms_backend_operations_total{outcome!~"success|cancelled"}[5m]))
+            /
+            clamp_min(sum(rate(rustfs_kms_backend_operations_total[5m])), 1e-9)
+          ) > 0.05
+          and
+          sum(rate(rustfs_kms_backend_operations_total[5m])) > 0.02
+        for: 10m
+        labels:
+          severity: critical
+          component: kms
+        annotations:
+          summary: "KMS backend non-success ratio above 5% for 10m"
+          description: >-
+            {{ $value | humanizePercentage }} of KMS backend operations
+            are terminating in fatal, budget_exhausted, or
+            deadline_exceeded. Object encryption and decryption paths
+            depending on the KMS are degraded or failing.
+          runbook_url: "https://github.com/rustfs/rustfs/blob/main/docs/operations/kms-observability-runbook.md#kmsbackendhigherrorrate"
+
+  # ==========================================================================
+  # Warning alerts — investigation needed
+  # ==========================================================================
+  - name: rustfs-kms-warning
+    interval: 30s
+    rules:
+      # ------------------------------------------------------------------
+      # 3. KmsBackendP99LatencyHigh
+      #    p99 wall-clock duration of whole operations (attempts plus
+      #    backoff) is sustained above 2 seconds. Because the histogram
+      #    includes retries, a high p99 usually means the retry policy
+      #    is absorbing backend failures, not that every call is slow.
+      #    Threshold: 2s for 10m — conservative default, calibrate
+      #    against a staging baseline.
+      # ------------------------------------------------------------------
+      - alert: KmsBackendP99LatencyHigh
+        expr: |
+          histogram_quantile(0.99,
+            sum by (le) (rate(rustfs_kms_backend_operation_duration_seconds_bucket[5m]))
+          ) > 2
+        for: 10m
+        labels:
+          severity: warning
+          component: kms
+        annotations:
+          summary: "KMS backend operation p99 latency above 2s for 10m"
+          description: >-
+            The 99th-percentile KMS backend operation duration is
+            {{ $value | humanizeDuration }}, including retries and
+            backoff. Encryption and decryption latency is leaking into
+            S3 request latency.
+          runbook_url: "https://github.com/rustfs/rustfs/blob/main/docs/operations/kms-observability-runbook.md#kmsbackendp99latencyhigh"
+
+      # ------------------------------------------------------------------
+      # 4. KmsBackendAttemptFailureSpike
+      #    Aggregate attempt-failure rate (all error classes) sustained
+      #    above an absolute floor. An absolute threshold is used instead
+      #    of an offset-1d baseline ratio because fresh deployments have
+      #    no baseline and an empty offset vector would keep a ratio
+      #    alert from ever firing; switch to a baseline-relative form
+      #    (see rustfs-get-optimization-alerts.yaml for the pattern)
+      #    once a stable staging baseline exists.
+      #    Threshold: 0.5/s for 10m — conservative default, calibrate
+      #    against a staging baseline.
+      # ------------------------------------------------------------------
+      - alert: KmsBackendAttemptFailureSpike
+        expr: |
+          sum(rate(rustfs_kms_backend_attempt_failures_total[5m])) > 0.5
+        for: 10m
+        labels:
+          severity: warning
+          component: kms
+        annotations:
+          summary: "KMS backend attempt failures above 0.5/s for 10m"
+          description: >-
+            KMS backend attempts are failing at
+            {{ $value | printf "%.2f" }}/s across all error classes.
+            The retry policy may still be masking these from callers —
+            check the error-class breakdown before it stops absorbing
+            them.
+          runbook_url: "https://github.com/rustfs/rustfs/blob/main/docs/operations/kms-observability-runbook.md#kmsbackendattemptfailurespike"
+
+      # ------------------------------------------------------------------
+      # 5. KmsBackendRetryBudgetExhausted
+      #    Operations are running out of retry budget (budget_exhausted)
+      #    or operation deadline (deadline_exceeded). These surface to
+      #    callers as failed KMS operations even though every individual
+      #    failure was retryable — the backend is unhealthy for longer
+      #    than the policy can bridge.
+      #    Threshold: 0.05/s for 10m — conservative default, calibrate
+      #    against a staging baseline.
+      # ------------------------------------------------------------------
+      - alert: KmsBackendRetryBudgetExhausted
+        expr: |
+          sum by (outcome) (rate(rustfs_kms_backend_operations_total{outcome=~"budget_exhausted|deadline_exceeded"}[5m])) > 0.05
+        for: 10m
+        labels:
+          severity: warning
+          component: kms
+        annotations:
+          summary: "KMS backend operations exhausting retry budget ({{ $labels.outcome }})"
+          description: >-
+            KMS backend operations are terminating as
+            {{ $labels.outcome }} at {{ $value | printf "%.3f" }}/s.
+            Retryable failures are outlasting the retry budget, so
+            callers are seeing hard failures.
+          runbook_url: "https://github.com/rustfs/rustfs/blob/main/docs/operations/kms-observability-runbook.md#kmsbackendretrybudgetexhausted"
@@ -25,9 +25,13 @@ inputs:
    required: false
    default: "rustfs-deps"
  cache-save-if:
-    description: "Condition for saving cache"
+    description: >-
+      Whether to save the cache. The fail-safe default is 'false': a caller that
+      wants to populate a cache must opt in explicitly, so a forgotten input
+      costs a cold cache (minutes) rather than silently consuming the
+      repository-wide 10GB Actions cache quota and evicting other lanes.
    required: false
-    default: "true"
+    default: "false"
  install-cross-tools:
    description: "Install cross-compilation tools"
    required: false
@@ -36,28 +40,43 @@ inputs:
    description: "Target architecture to add"
    required: false
    default: ""
-  github-token:
-    description: "GitHub token for API access"
+  install-build-packaging-tools:
+    description: >-
+      Install musl-tools/zip/unzip, needed for musl linking and release
+      packaging. Off for CI test lanes, which use none of them.
    required: false
-    default: ""
+    default: "true"
+  install-test-tools:
+    description: >-
+      Install cargo-nextest and the rustfmt/clippy components. Off for release
+      and audit lanes, which run no tests and no lints.
+    required: false
+    default: "true"

 runs:
  using: "composite"
  steps:
+    # protobuf-compiler is deliberately absent: the setup-protoc step below
+    # installs 34.1 into the tool cache and prepends it to PATH, so the apt
+    # build (older, and never version-matched) was shadowed on every run and
+    # simply never used.
    - name: Install system dependencies (Ubuntu)
      if: runner.os == 'Linux'
      shell: bash
      run: |
        sudo apt-get update
        sudo apt-get install -y \
-          musl-tools \
          build-essential \
          pkg-config \
          libssl-dev \
-          ripgrep \
-          unzip \
-          zip \
-          protobuf-compiler
+          ripgrep
+
+    # musl-gcc is needed by the native musl release leg, and zip/unzip by the
+    # release packaging steps. No CI test lane touches any of them.
+    - name: Install packaging and cross-linking dependencies (Ubuntu)
+      if: runner.os == 'Linux' && inputs.install-build-packaging-tools == 'true'
+      shell: bash
+      run: sudo apt-get install -y musl-tools zip unzip

    - name: Install protoc
      uses: rustfs/setup-protoc@a3705324d8f9bf5b6c3573fb6cf8ae421db55dd6 # v3.0.1
@@ -75,7 +94,7 @@ runs:
      with:
        toolchain: ${{ inputs.rust-version }}
        targets: ${{ inputs.target }}
-        components: rustfmt, clippy
+        components: ${{ inputs.install-test-tools == 'true' && 'rustfmt, clippy' || '' }}

    - name: Install Zig
      if: inputs.install-cross-tools == 'true'
@@ -86,12 +105,24 @@ runs:
      uses: taiki-e/install-action@a21ae4029b089b9ddc45704028756f51ab8abe48 # cargo-zigbuild

    - name: Install cargo-nextest
+      if: inputs.install-test-tools == 'true'
      uses: taiki-e/install-action@96c7780c1d8a2b8723e12031def873a434d39d8d # nextest

    - name: Setup Rust cache
      uses: Swatinem/rust-cache@e18b497796c12c097a38f9edb9d0641fb99eee32 # v2
      with:
-        cache-all-crates: true
+        # false is rust-cache's own default. With true, cleanup.ts returns
+        # *before* pruning ~/.cargo/registry/src, and config.ts archives the
+        # whole registry — so every cache carried the unpacked source tree of
+        # every dependency, not just "a few extra crates".
+        #
+        # No coverage is lost: getPackages runs `cargo metadata --all-features`,
+        # a strict superset of any single lane's feature closure, and -sys crates
+        # are explicitly exempted from pruning (their src timestamps would
+        # otherwise trigger rebuilds). Anything pruned is re-unpacked from the
+        # .crate files still in registry/cache, whose mtimes crates.io
+        # normalises, so cargo fingerprints stay valid.
+        cache-all-crates: false
        cache-on-failure: true
        shared-key: ${{ inputs.cache-shared-key }}
        save-if: ${{ inputs.cache-save-if }}
@@ -37,6 +37,7 @@ jobs:
    name: Cancel Closed PR Runs
    if: github.event_name == 'pull_request' && github.event.action == 'closed'
    runs-on: ubuntu-latest
+    timeout-minutes: 10
    steps:
      - name: Explain cancellation run
        run: echo "PR closed; this run only cancels older runs in the same concurrency group."
@@ -45,8 +46,11 @@ jobs:
    name: Architecture Migration Rules
    if: github.event_name != 'pull_request' || github.event.action != 'closed'
    runs-on: ubuntu-latest
+    timeout-minutes: 10
    steps:
      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Install ripgrep
        run: |
@@ -23,6 +23,8 @@ on:
      - 'deny.toml'
      - '.github/actions/**'
      - '.github/workflows/**'
+      - 'scripts/release/create_or_update_release.sh'
+      - 'scripts/security/check_preview_release_workflow.sh'
      - 'scripts/security/check_workflow_pins.sh'
  pull_request:
    types: [ opened, synchronize, reopened, closed ]
@@ -33,9 +35,16 @@ on:
      - 'deny.toml'
      - '.github/actions/**'
      - '.github/workflows/**'
+      - 'scripts/release/create_or_update_release.sh'
+      - 'scripts/security/check_preview_release_workflow.sh'
      - 'scripts/security/check_workflow_pins.sh'
  schedule:
-    - cron: '0 3 * * 0' # Weekly on Sunday 03:00 UTC (staggered after the midnight ci/build crons)
+    # Daily, not weekly. This schedule exists to catch RustSec advisories
+    # published against an unchanged dependency tree; at weekly cadence a new
+    # advisory could sit unnoticed for seven days. The check list is unchanged —
+    # splitting it into a light daily advisories-only run and a weekly full run
+    # would create runs where sources/bans/licenses go unverified.
+    - cron: '0 3 * * *' # Daily 03:00 UTC (staggered after the midnight ci/build crons)
  workflow_dispatch:

 permissions:
@@ -55,6 +64,7 @@ jobs:
    name: Cancel Closed PR Runs
    if: github.event_name == 'pull_request' && github.event.action == 'closed'
    runs-on: ubuntu-latest
+    timeout-minutes: 10
    steps:
      - name: Explain cancellation run
        run: echo "PR closed; this run only cancels older runs in the same concurrency group."
@@ -70,11 +80,32 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
-
-      - name: Setup Rust environment
-        uses: ./.github/actions/setup
        with:
-          cache-shared-key: rustfs-cargo-deny
+          persist-credentials: false
+
+      # cargo-deny compiles nothing, so the full setup composite (apt packages,
+      # protoc, flatc, nextest, rustfmt/clippy) was pure overhead here. It does
+      # still need a real cargo: `cargo deny check` runs `cargo metadata`, and
+      # Cargo.toml pins datafusion and s3s as git dependencies, which must be
+      # materialised into ~/.cargo/git — a cold clone is hundreds of MB, so the
+      # cache stays.
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@29eef336d9b2848a0b548edc03f92a220660cdb8 # stable
+
+      # Was relying on the composite's default, which used to be "true": every
+      # PR touching Cargo.toml/Cargo.lock saved a second, PR-scoped copy of this
+      # cache and pushed the main-scoped lanes out of the 10GB quota. The
+      # default is now "false", but state it explicitly — see
+      # scripts/security/check_cache_save_if.sh.
+      - name: Setup Rust cache
+        uses: Swatinem/rust-cache@e18b497796c12c097a38f9edb9d0641fb99eee32 # v2
+        with:
+          # Same reasoning as the setup composite: true archives every
+          # dependency's unpacked source tree.
+          cache-all-crates: false
+          cache-on-failure: true
+          shared-key: rustfs-cargo-deny
+          save-if: ${{ github.ref == 'refs/heads/main' }}

      - name: Install cargo-deny
        uses: taiki-e/install-action@bffeee26d4db9be238a4ea78d8826604ebcb594d # v2
@@ -92,13 +123,28 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Report unpinned GitHub Actions
        run: ./scripts/security/check_workflow_pins.sh --enforce

+      - name: Check setup cache-save-if is explicit
+        run: ./scripts/security/check_cache_save_if.sh
+
+      - name: Check every job declares a timeout
+        run: ./scripts/security/check_job_timeouts.sh
+
+      - name: Check checkouts clear their credentials
+        run: ./scripts/security/check_persist_credentials.sh
+
+      - name: Check preview release workflow policy
+        run: ./scripts/security/check_preview_release_workflow.sh
+
  dependency-review:
    name: Dependency Review
    runs-on: ubuntu-latest
+    timeout-minutes: 30
    if: github.event_name == 'pull_request' && github.event.action != 'closed'
    permissions:
      contents: read
@@ -106,6 +152,8 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Dependency Review
        uses: actions/dependency-review-action@a1d282b36b6f3519aa1f3fc636f609c47dddb294 # v5
@@ -118,3 +166,28 @@ jobs:
          # conscious re-review of the license/provenance claim (backlog#1181).
          allow-dependencies-licenses: pkg:cargo/rustfs-uring@0.1.0
          comment-summary-in-pr: always
+
+  alert-on-failure:
+    name: Alert on scheduled failure
+    # dependency-review is deliberately excluded: it only runs on pull_request,
+    # so it can never contribute a failure to a scheduled run.
+    needs: [cargo-deny, workflow-pin-report]
+    # A scheduled cargo-deny failure usually means the dependency tree just
+    # matched a newly published advisory — the single most important signal this
+    # workflow produces, and until now it was only visible to whoever happened to
+    # open the Actions tab. Same ci-8 mechanism coverage.yml and
+    # e2e-replication-nightly.yml already use.
+    if: always() && github.event_name == 'schedule' && contains(needs.*.result, 'failure')
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    permissions:
+      contents: read
+      issues: write
+    steps:
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
+      - name: Open or update failure-tracking issue
+        uses: ./.github/actions/schedule-failure-issue
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
@@ -50,12 +50,18 @@ on:
      - "**/*.svg"
      - ".gitignore"
      - ".dockerignore"
+      - "flake.lock"
  schedule:
    - cron: "0 1 * * 0" # Weekly on Sunday 01:00 UTC (staggered after the ci.yml midnight cron)
  workflow_dispatch:
    inputs:
      build_docker:
-        description: "Build and push Docker images after binary build"
+        # Advisory only. docker.yml triggers on workflow_run and its job-level
+        # condition requires the triggering event to be a tag push, so a manual
+        # dispatch of this workflow never produces images regardless of this
+        # value. Kept because the summary step reports it; wiring it up would
+        # mean teaching docker.yml's version parser a second event shape.
+        description: "Build and push Docker images after binary build (ignored: dispatch runs never reach docker.yml)"
        required: false
        default: true
        type: boolean
@@ -83,6 +89,7 @@ jobs:
  build-check:
    name: Build Strategy Check
    runs-on: ubuntu-latest
+    timeout-minutes: 30
    outputs:
      should_build: ${{ steps.check.outputs.should_build }}
      build_type: ${{ steps.check.outputs.build_type }}
@@ -92,6 +99,8 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Determine build strategy
        id: check
@@ -107,13 +116,21 @@ jobs:

          # Determine build type based on trigger
          if [[ "${{ startsWith(github.ref, 'refs/tags/') }}" == "true" ]]; then
-            # Tag push - release or prerelease
+            # Tag push - preview, release, or prerelease
            should_build=true
            tag_name="${GITHUB_REF#refs/tags/}"
            version="${tag_name}"

-            # Check if this is a prerelease
-            if [[ "$tag_name" == *"alpha"* ]] || [[ "$tag_name" == *"beta"* ]] || [[ "$tag_name" == *"rc"* ]]; then
+            # Preview tags publish a GitHub prerelease for validation, but
+            # must not update any latest channel.
+            if [[ "$tag_name" =~ -preview\.[0-9]+$ ]]; then
+              build_type="preview"
+              is_prerelease=true
+              echo "🔍 Preview build detected: $tag_name"
+            elif [[ "$tag_name" == *"-preview"* ]]; then
+              echo "❌ Invalid preview tag: $tag_name (expected suffix: -preview.<number>)" >&2
+              exit 1
+            elif [[ "$tag_name" == *"alpha"* ]] || [[ "$tag_name" == *"beta"* ]] || [[ "$tag_name" == *"rc"* ]]; then
              build_type="prerelease"
              is_prerelease=true
              echo "🚀 Prerelease build detected: $tag_name"
@@ -156,6 +173,7 @@ jobs:
    name: Prepare Platform Matrix
    needs: build-check
    runs-on: ubuntu-latest
+    timeout-minutes: 30
    outputs:
      matrix: ${{ steps.select.outputs.matrix }}
      selected: ${{ steps.select.outputs.selected }}
@@ -163,10 +181,14 @@ jobs:
      - name: Select target platforms
        id: select
        shell: bash
+        env:
+          # via env, not interpolation: a dispatch input is free-form text and
+          # would otherwise be pasted into the script for bash to evaluate.
+          RAW_PLATFORMS: ${{ github.event_name == 'workflow_dispatch' && github.event.inputs.platforms || 'all' }}
        run: |
          set -euo pipefail

-          selected="${{ github.event_name == 'workflow_dispatch' && github.event.inputs.platforms || 'all' }}"
+          selected="$RAW_PLATFORMS"
          selected="$(echo "${selected}" | tr -d '[:space:]')"
          if [[ -z "${selected}" ]]; then
            selected="all"
@@ -237,6 +259,7 @@ jobs:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
        with:
+          persist-credentials: false
          fetch-depth: 0

      - name: Setup Rust environment
@@ -245,9 +268,17 @@ jobs:
          rust-version: stable
          target: ${{ matrix.target }}
          cache-shared-key: build-${{ matrix.target }}
-          github-token: ${{ secrets.GITHUB_TOKEN }}
-          cache-save-if: ${{ github.ref == 'refs/heads/main' || startsWith(github.ref, 'refs/tags/') }}
+          # main only. A cache saved on refs/tags/X is scoped to that tag: no
+          # other tag, no main run and no PR can restore it, so every release
+          # cycle wrote up to 12 entries of 1-2GB (preview tag plus final tag,
+          # six legs each) that nobody could read, evicting the hot lanes from
+          # the repo-wide 10GB quota. Tag builds still restore the main-scoped
+          # cache, since default-branch caches are readable from every ref.
+          # The one real cost: re-running a failed leg of the same tag no longer
+          # finds that tag's own warm cache and falls back to main's.
+          cache-save-if: ${{ github.ref == 'refs/heads/main' }}
          install-cross-tools: ${{ matrix.cross }}
+          install-test-tools: 'false'

      - name: Download static console assets
        shell: bash
@@ -694,9 +725,14 @@ jobs:
    needs: [ build-check, build-rustfs ]
    if: always() && needs.build-check.outputs.should_build == 'true'
    runs-on: ubuntu-latest
+    timeout-minutes: 10
    steps:
      - name: Build completion summary
        shell: bash
+        env:
+          # dispatch input via env: free-form text must not be pasted into the
+          # script for bash to evaluate.
+          INPUT_BUILD_DOCKER: ${{ github.event.inputs.build_docker }}
        run: |
          BUILD_TYPE="${{ needs.build-check.outputs.build_type }}"
          VERSION="${{ needs.build-check.outputs.version }}"
@@ -714,6 +750,10 @@ jobs:
          echo ""

          case "$BUILD_TYPE" in
+            "preview")
+              echo "🔍 Preview artifacts are published in a GitHub prerelease"
+              echo "⏭️  Preview releases do not update latest channels"
+              ;;
            "development")
              echo "🛠️  Development build artifacts have been uploaded to OSS dev directory"
              echo "⚠️  This is a development build - not suitable for production use"
@@ -732,7 +772,9 @@ jobs:

          echo ""
          echo "🐳 Docker Images:"
-          if [[ "${{ github.event.inputs.build_docker }}" == "false" ]]; then
+          if [[ "$BUILD_TYPE" == "preview" ]]; then
+            echo "⏭️  Preview tags do not publish Docker images"
+          elif [[ "$INPUT_BUILD_DOCKER" == "false" ]]; then
            echo "⏭️  Docker image build was skipped (binary only build)"
          elif [[ "$BUILD_STATUS" == "success" ]]; then
            echo "🔄 Docker images will be built and pushed automatically via workflow_run event"
@@ -740,12 +782,13 @@ jobs:
            echo "❌ Docker image build will be skipped due to build failure"
          fi

-  # Create GitHub Release (only for tag pushes)
+  # Create GitHub Release for every valid release tag, including previews
  create-release:
    name: Create GitHub Release
    needs: [ build-check, build-rustfs ]
-    if: startsWith(github.ref, 'refs/tags/') && needs.build-check.outputs.build_type != 'development'
+    if: startsWith(github.ref, 'refs/tags/') && (needs.build-check.outputs.build_type == 'preview' || needs.build-check.outputs.build_type == 'release' || needs.build-check.outputs.build_type == 'prerelease')
    runs-on: ubuntu-latest
+    timeout-minutes: 30
    permissions:
      contents: write
    outputs:
@@ -755,6 +798,7 @@ jobs:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
        with:
+          persist-credentials: false
          fetch-depth: 0

      - name: Create GitHub Release
@@ -767,9 +811,12 @@ jobs:
          VERSION="${{ needs.build-check.outputs.version }}"
          IS_PRERELEASE="${{ needs.build-check.outputs.is_prerelease }}"
          BUILD_TYPE="${{ needs.build-check.outputs.build_type }}"
+          TARGET_COMMITISH=$(git rev-parse --verify "refs/tags/${TAG}^{commit}")

          # Determine release type for title
-          if [[ "$BUILD_TYPE" == "prerelease" ]]; then
+          if [[ "$BUILD_TYPE" == "preview" ]]; then
+            RELEASE_TYPE="preview"
+          elif [[ "$BUILD_TYPE" == "prerelease" ]]; then
            if [[ "$TAG" == *"alpha"* ]]; then
              RELEASE_TYPE="alpha"
            elif [[ "$TAG" == *"beta"* ]]; then
@@ -783,61 +830,34 @@ jobs:
            RELEASE_TYPE="release"
          fi

-          # Check if release already exists
-          if gh release view "$TAG" >/dev/null 2>&1; then
-            echo "Release $TAG already exists"
-            RELEASE_ID=$(gh release view "$TAG" --json databaseId --jq '.databaseId')
-            RELEASE_URL=$(gh release view "$TAG" --json url --jq '.url')
+          # Create release title
+          if [[ "$IS_PRERELEASE" == "true" ]]; then
+            TITLE="RustFS $VERSION (${RELEASE_TYPE})"
          else
-            # Get release notes from tag message
-            RELEASE_NOTES=$(git tag -l --format='%(contents)' "${TAG}")
-            if [[ -z "$RELEASE_NOTES" || "$RELEASE_NOTES" =~ ^[[:space:]]*$ ]]; then
-              if [[ "$IS_PRERELEASE" == "true" ]]; then
-                RELEASE_NOTES="Pre-release ${VERSION} (${RELEASE_TYPE})"
-              else
-                RELEASE_NOTES="Release ${VERSION}"
-              fi
-            fi
-
-            # Create release title
-            if [[ "$IS_PRERELEASE" == "true" ]]; then
-              TITLE="RustFS $VERSION (${RELEASE_TYPE})"
-            else
-              TITLE="RustFS $VERSION"
-            fi
-
-            # Create the release
-            PRERELEASE_FLAG=""
-            if [[ "$IS_PRERELEASE" == "true" ]]; then
-              PRERELEASE_FLAG="--prerelease"
-            fi
-
-            gh release create "$TAG" \
-              --title "$TITLE" \
-              --notes "$RELEASE_NOTES" \
-              $PRERELEASE_FLAG \
-              --draft
-
-            RELEASE_ID=$(gh release view "$TAG" --json databaseId --jq '.databaseId')
-            RELEASE_URL=$(gh release view "$TAG" --json url --jq '.url')
+            TITLE="RustFS $VERSION"
          fi

-          echo "release_id=$RELEASE_ID" >> "$GITHUB_OUTPUT"
-          echo "release_url=$RELEASE_URL" >> "$GITHUB_OUTPUT"
-          echo "Created release: $RELEASE_URL"
+          ./scripts/release/create_or_update_release.sh \
+            "$TAG" \
+            "$TARGET_COMMITISH" \
+            "$TITLE" \
+            "$IS_PRERELEASE"

  # Prepare and upload release assets
  upload-release-assets:
    name: Upload Release Assets
    needs: [ build-check, build-rustfs, create-release ]
-    if: startsWith(github.ref, 'refs/tags/') && needs.build-check.outputs.build_type != 'development'
+    if: startsWith(github.ref, 'refs/tags/') && (needs.build-check.outputs.build_type == 'preview' || needs.build-check.outputs.build_type == 'release' || needs.build-check.outputs.build_type == 'prerelease')
    runs-on: ubuntu-latest
+    timeout-minutes: 30
    permissions:
      contents: write
      actions: read
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Download all build artifacts
        uses: actions/download-artifact@37930b1c2abaa49bbe596cd826c3c89aef350131 # v7
@@ -920,9 +940,10 @@ jobs:
  # the pointed-to version is a prerelease.
  update-latest-version:
    name: Update Latest Version
-    needs: [ build-check, upload-release-assets ]
-    if: startsWith(github.ref, 'refs/tags/')
+    needs: [ build-check, publish-release ]
+    if: startsWith(github.ref, 'refs/tags/') && (needs.build-check.outputs.build_type == 'release' || needs.build-check.outputs.build_type == 'prerelease')
    runs-on: ubuntu-latest
+    timeout-minutes: 30
    steps:
      - name: Update latest.json
        env:
@@ -980,51 +1001,34 @@ jobs:
  publish-release:
    name: Publish Release
    needs: [ build-check, create-release, upload-release-assets ]
-    if: startsWith(github.ref, 'refs/tags/') && needs.build-check.outputs.build_type != 'development'
+    if: startsWith(github.ref, 'refs/tags/') && (needs.build-check.outputs.build_type == 'preview' || needs.build-check.outputs.build_type == 'release' || needs.build-check.outputs.build_type == 'prerelease')
    runs-on: ubuntu-latest
+    timeout-minutes: 30
    permissions:
      contents: write
    steps:
-      - name: Checkout repository
-        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
-
-      - name: Update release notes and publish
+      - name: Publish release
        env:
          GH_TOKEN: ${{ github.token }}
        shell: bash
        run: |
          TAG="${{ needs.build-check.outputs.version }}"
-          VERSION="${{ needs.build-check.outputs.version }}"
-          IS_PRERELEASE="${{ needs.build-check.outputs.is_prerelease }}"
          BUILD_TYPE="${{ needs.build-check.outputs.build_type }}"
+          RELEASE_ID="${{ needs.create-release.outputs.release_id }}"

-          # Determine release type
-          if [[ "$BUILD_TYPE" == "prerelease" ]]; then
-            if [[ "$TAG" == *"alpha"* ]]; then
-              RELEASE_TYPE="alpha"
-            elif [[ "$TAG" == *"beta"* ]]; then
-              RELEASE_TYPE="beta"
-            elif [[ "$TAG" == *"rc"* ]]; then
-              RELEASE_TYPE="rc"
-            else
-              RELEASE_TYPE="prerelease"
-            fi
+          # Publish the release and correct its channel state on retries.
+          # Only a stable final release may become GitHub Latest.
+          if [[ "$BUILD_TYPE" == "release" ]]; then
+            gh api --method PATCH "repos/${GITHUB_REPOSITORY}/releases/${RELEASE_ID}" \
+              -F draft=false \
+              -F prerelease=false \
+              -f make_latest=true >/dev/null
          else
-            RELEASE_TYPE="release"
+            gh api --method PATCH "repos/${GITHUB_REPOSITORY}/releases/${RELEASE_ID}" \
+              -F draft=false \
+              -F prerelease=true \
+              -f make_latest=false >/dev/null
          fi

-          # Get original release notes from tag
-          ORIGINAL_NOTES=$(git tag -l --format='%(contents)' "${TAG}")
-          if [[ -z "$ORIGINAL_NOTES" || "$ORIGINAL_NOTES" =~ ^[[:space:]]*$ ]]; then
-            if [[ "$IS_PRERELEASE" == "true" ]]; then
-              ORIGINAL_NOTES="Pre-release ${VERSION} (${RELEASE_TYPE})"
-            else
-              ORIGINAL_NOTES="Release ${VERSION}"
-            fi
-          fi
-
-          # Publish the release (remove draft status)
-          gh release edit "$TAG" --draft=false
-
          echo "🎉 Released $TAG successfully!"
          echo "📄 Release URL: ${{ needs.create-release.outputs.release_url }}"
@@ -0,0 +1,265 @@
+# Copyright 2026 RustFS Team
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Sole writer of the Rust dependency caches that ci.yml restores.
+#
+# Why this is a separate workflow rather than steps inside ci.yml: ci.yml's
+# concurrency group cancels in-progress runs on main pushes, and merges land far
+# faster than its 70-minute pipeline. Measured over 15 consecutive main pushes:
+# 12 cancelled, 2 failed, 0 succeeded. A cancelled run never reaches
+# Swatinem/rust-cache's post step (cache-on-failure does not cover cancellation),
+# so the writer lanes were saving nothing and every PR paid a cold restore —
+# 11.8-20.9 minutes of "Setup Rust environment" against 0.7-3.4 warm.
+#
+# Splitting cache writing out of the test pipeline lets ci.yml keep cancelling
+# superseded runs (which is correct — nobody needs test results for a commit
+# that is already three merges behind) while the caches still get written.
+#
+# The group below deliberately does NOT cancel in progress; see the comment on
+# it for how that bounds concurrency and why it is scoped by event.
+#
+# Each job below owns exactly one shared-key and is the only place that sets
+# cache-save-if to anything but 'false' for it; every lane in ci.yml reads.
+# scripts/security/check_cache_save_if.sh keeps the declarations explicit.
+#
+# The builds are supersets of what the reading lanes compile, because a reader
+# restores only what the writer saved. Feature resolution matters here: a lane
+# built with e2e-test-hooks resolves dependency features differently, which
+# changes -Cmetadata, so the plain build does not cover it. See
+# rustfs/backlog#1600.
+
+name: Cache Warm
+
+on:
+  push:
+    branches: [ main ]
+    # Mirrors ci.yml's push paths-ignore: if a commit cannot change what ci.yml
+    # compiles, it cannot change what ci.yml needs restored either.
+    paths-ignore:
+      - "**.md"
+      - "docs/**"
+      - "deploy/**"
+      - "scripts/dev_*.sh"
+      - "scripts/probe.sh"
+      - "LICENSE*"
+      - ".gitignore"
+      - ".dockerignore"
+      - "README*"
+      - "**/*.png"
+      - "**/*.jpg"
+      - "**/*.svg"
+      - ".github/workflows/build.yml"
+      - ".github/workflows/docker.yml"
+      - ".github/workflows/audit.yml"
+  workflow_dispatch:
+    inputs:
+      emit_timings:
+        description: >-
+          Also emit cargo --timings for the ci-dev build and upload it. Used to
+          decide whether sccache is worth adopting (rustfs/backlog#1601 gate).
+        required: false
+        default: false
+        type: boolean
+
+permissions:
+  contents: read
+
+# Scoped by event. A push run and a dispatch run do not compete: GitHub keeps
+# one running plus one pending per group, so with a single shared group a
+# manually dispatched run was displaced as pending by the next merge and
+# cancelled — observed three times in a row, which made the --timings gate in
+# rustfs/backlog#1601 effectively impossible to trigger while main was busy.
+#
+# Still no cancel-in-progress: a burst of merges collapses into "current run
+# finishes, newest queued run follows" rather than a pile-up, which is what
+# bounds this workflow to one self-hosted runner per event type.
+#
+# The two paths can now overlap and race to save the same key. That is benign:
+# the loser finds the key already present and skips, and both builds produce the
+# same artifacts from the same commit.
+concurrency:
+  group: cache-warm-${{ github.event_name }}
+  cancel-in-progress: false
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  # Readers: test-and-lint, test-ilm-integration-serial, build-rustfs-debug-binary,
+  # e2e-tests, e2e-full.
+  warm-ci-dev:
+    name: Warm ci-dev
+    runs-on: sm-standard-4
+    timeout-minutes: 90
+    env:
+      FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: "true"
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
+
+      - name: Setup Rust environment
+        uses: ./.github/actions/setup
+        with:
+          rust-version: stable
+          cache-shared-key: ci-dev
+          cache-save-if: 'true'
+          install-build-packaging-tools: 'false'
+
+      # rustfs/backlog#1601 gate. sccache can only cache compilation units whose
+      # --emit includes link, so it covers workspace rlibs and nothing else:
+      # clippy is metadata-only, and the ~100 test binaries, the rustfs bin and
+      # every build script invoke the system linker. Before spending a bucket,
+      # credentials and a supply-chain boundary on it, measure how much of the
+      # build is actually rlib codegen.
+      #
+      # Read from the report: workspace lib codegen as a share of the build, and
+      # s3select-query's own rlib as a share. The plan adopts sccache only above
+      # 50% and 25% respectively; if linking dominates instead, the answer is
+      # mold/lld plus split-debuginfo, which is exactly the part sccache cannot
+      # touch. Off by default — this doubles the ci-dev build.
+      - name: Build ci-dev superset (with --timings)
+        if: inputs.emit_timings
+        env:
+          CARGO_BUILD_JOBS: "2"
+        run: cargo build --workspace --all-targets --timings
+
+      - name: Upload cargo timings report
+        if: inputs.emit_timings
+        uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6
+        with:
+          name: cargo-timings-ci-dev
+          path: target/cargo-timings/
+          retention-days: 30
+          if-no-files-found: error
+
+      # --all-targets covers the test binaries nextest builds, including
+      # e2e_test, which test-and-lint's own run excludes. The second build adds
+      # the e2e-test-hooks feature resolution that build-rustfs-debug-binary uses
+      # and that no lint lane enables.
+      - name: Build ci-dev superset
+        env:
+          # Same limit ci.yml puts on its nextest step: this builds the same
+          # ~100 workspace test binaries, and three concurrent links saturate the
+          # self-hosted runner's overlay I/O and can wedge Cargo (#5394).
+          CARGO_BUILD_JOBS: "2"
+        run: |
+          cargo build --workspace --all-targets
+          cargo build -p rustfs --bins --features e2e-test-hooks
+
+      # Runs before rust-cache's post step, so these are the sizes it is about
+      # to archive. Reported so the cache-all-crates decision stays evidence-led:
+      # registry/src is what that flag prunes, registry/cache is what the pruned
+      # sources are re-unpacked from. See rustfs/backlog#1600.
+      - name: Report cache input sizes
+        if: always()
+        run: |
+          # tee, not a plain redirect: sent only to $GITHUB_STEP_SUMMARY these
+          # numbers are readable in the UI but absent from the job log, and the
+          # REST API exposes the log, not the summary — which made the figures
+          # unreachable for exactly the scripted comparison they exist for.
+          sizes="$(du -sh ~/.cargo/registry/src ~/.cargo/registry/cache \
+                          ~/.cargo/registry/index ~/.cargo/git target 2>/dev/null || true)"
+          echo "cache-input-sizes-begin"
+          printf '%s\n' "$sizes"
+          echo "cache-input-sizes-end"
+          {
+            echo "### Cache input sizes (ci-dev)"
+            echo '```'
+            printf '%s\n' "$sizes"
+            echo '```'
+          } >> "$GITHUB_STEP_SUMMARY"
+
+  # Readers: test-and-lint-rio-v2, build-rustfs-debug-binary-rio-v2.
+  warm-ci-feat-rio:
+    name: Warm ci-feat-rio
+    runs-on: sm-standard-4
+    timeout-minutes: 90
+    env:
+      FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: "true"
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
+
+      - name: Setup Rust environment
+        uses: ./.github/actions/setup
+        with:
+          rust-version: stable
+          cache-shared-key: ci-feat-rio
+          cache-save-if: 'true'
+          install-build-packaging-tools: 'false'
+
+      - name: Build ci-feat-rio superset
+        run: |
+          cargo build -p rustfs -p rustfs-ecstore --all-targets --features rio-v2
+          cargo build -p rustfs --bins --features rio-v2,e2e-test-hooks
+
+  # Readers: the swift and sftp legs of test-and-lint-protocols. Built in
+  # sequence rather than as `--features swift,sftp`, which is a combination no
+  # lane actually compiles; running both leaves the union in target/.
+  warm-ci-feat-proto:
+    name: Warm ci-feat-proto
+    runs-on: sm-standard-4
+    timeout-minutes: 90
+    env:
+      FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: "true"
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
+
+      - name: Setup Rust environment
+        uses: ./.github/actions/setup
+        with:
+          rust-version: stable
+          cache-shared-key: ci-feat-proto
+          cache-save-if: 'true'
+          install-build-packaging-tools: 'false'
+
+      - name: Build ci-feat-proto superset
+        run: |
+          cargo build -p rustfs -p rustfs-protocols --all-targets --features swift
+          cargo build -p rustfs -p rustfs-protocols --all-targets --features sftp
+
+  # Reader: uring-integration. Runs on ubuntu-latest to match it: rust-cache's
+  # key covers runner.os and arch but not the runner label or image, so a cache
+  # written on sm-standard-4 would be restored by the hosted runner as if it
+  # belonged to it.
+  warm-ci-uring:
+    name: Warm ci-uring
+    runs-on: ubuntu-latest
+    timeout-minutes: 60
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
+
+      - name: Setup Rust environment
+        uses: ./.github/actions/setup
+        with:
+          rust-version: stable
+          cache-shared-key: ci-uring
+          cache-save-if: 'true'
+          install-build-packaging-tools: 'false'
+
+      - name: Install build dependencies
+        run: sudo apt-get update && sudo apt-get install -y protobuf-compiler
+
+      - name: Build ci-uring superset
+        run: cargo build -p rustfs-ecstore --all-targets
@@ -12,18 +12,24 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-# Companion to ci.yml for the required "Test and Lint" status check.
+# Companion to ci.yml for required status checks.
 #
-# ci.yml skips docs-only pull requests via paths-ignore, but the branch
-# ruleset requires a check named "Test and Lint" — without this workflow a
-# docs-only PR would wait on that check forever. This workflow triggers on
-# exactly the paths ci.yml ignores and reports an instant success under the
-# same job name. Mixed PRs trigger both workflows and the real check still
-# gates: a required check with any failing run blocks the merge.
+# ci.yml skips docs-only pull requests via paths-ignore, but the branch ruleset
+# requires a check named "Test and Lint" — without this workflow a docs-only PR
+# would wait on it forever. This workflow triggers on exactly the paths ci.yml
+# ignores and reports success under the same job name. Mixed PRs trigger both
+# workflows and the real check still gates: a required check with any failing
+# run blocks the merge.
 # https://docs.github.com/en/repositories/configuring-branches-and-merges-in-your-repository/defining-the-mergeability-of-pull-requests/troubleshooting-required-status-checks#handling-skipped-but-required-checks
 #
+# "Quick Checks" is mirrored here ahead of the ruleset change that will make it
+# required too (rustfs/backlog#1599). Until that change lands this job is
+# inert; mirroring it first is what lets the ruleset change happen without
+# stranding docs-only PRs on a check nobody reports.
+#
 # Keep the paths list below in sync with the pull_request paths-ignore list
-# in ci.yml.
+# in ci.yml, and keep the quick-checks steps below byte-identical to the
+# quick-checks job in ci.yml.

 name: Continuous Integration (docs only)

@@ -47,17 +53,82 @@ on:
      - ".github/workflows/build.yml"
      - ".github/workflows/docker.yml"
      - ".github/workflows/audit.yml"
+      - "flake.lock"

 permissions:
  contents: read

 jobs:
-  test-and-lint:
-    name: Test and Lint
+  # Deliberately NOT a bare `echo`. Once "Quick Checks" becomes a required
+  # check, ci.yml gates every expensive job behind it, so a mixed PR reports
+  # two check runs with this name: the real one (45-51s) and this companion.
+  # GitHub has no written contract for how it picks between same-named
+  # required check runs ("latest wins" vs "any failure blocks"), so instead of
+  # relying on ordering we make both runs execute the same commands against
+  # the same merge ref — their conclusions are then necessarily identical and
+  # the choice does not matter. Keep these steps byte-identical to the
+  # quick-checks job in ci.yml (a guard script that asserts this, and the paths
+  # sync below, is tracked in rustfs/backlog#1603).
+  #
+  # For a genuinely docs-only PR this adds no strictness (no code changed, so
+  # fmt and the guards always pass) and costs ~50s of ubuntu-latest.
+  quick-checks:
+    name: Quick Checks
    runs-on: ubuntu-latest
+    timeout-minutes: 10
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
+
+      - name: Install ripgrep
+        run: sudo apt-get update && sudo apt-get install -y ripgrep
+
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@29eef336d9b2848a0b548edc03f92a220660cdb8 # stable
+        with:
+          components: rustfmt
+
+      - name: Check code formatting
+        run: cargo fmt --all --check
+
+      - name: Check unsafe code allowances
+        run: ./scripts/check_unsafe_code_allowances.sh
+
+      - name: Check layered dependencies
+        run: ./scripts/check_layer_dependencies.sh
+
+      - name: Check architecture migration rules
+        run: ./scripts/check_architecture_migration_rules.sh
+
+      - name: Check tokio io-uring feature guard
+        run: ./scripts/check_no_tokio_io_uring.sh
+
+      - name: Check extension schema boundaries
+        run: ./scripts/check_extension_schema_boundaries.sh
+
+      - name: Check body-cache whitelist guard
+        run: ./scripts/check_body_cache_whitelist.sh
+
+      - name: Check no planning docs committed
+        run: ./scripts/check_no_planning_docs.sh
+
+      - name: Check CI paths stay in sync
+        run: ./scripts/check_ci_paths_sync.sh
+
+      - name: Check io_uring lane --lib precondition
+        run: ./scripts/check_uring_lane_lib_only.sh
+
+  test-and-lint:
+    name: Test and Lint
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      # Docs-only PRs skip the full code CI, but they are exactly where a
      # planning-type document could be slipped in (git add -f bypasses
@@ -33,6 +33,7 @@ on:
      - ".github/workflows/build.yml"
      - ".github/workflows/docker.yml"
      - ".github/workflows/audit.yml"
+      - "flake.lock"
  pull_request:
    types: [ opened, synchronize, reopened, closed ]
    branches: [ main ]
@@ -54,6 +55,7 @@ on:
      - ".github/workflows/build.yml"
      - ".github/workflows/docker.yml"
      - ".github/workflows/audit.yml"
+      - "flake.lock"
  merge_group:
    types: [ checks_requested ]
  schedule:
@@ -81,6 +83,7 @@ jobs:
    name: Cancel Closed PR Runs
    if: github.event_name == 'pull_request' && github.event.action == 'closed'
    runs-on: ubuntu-latest
+    timeout-minutes: 10
    steps:
      - name: Explain cancellation run
        run: echo "PR closed; this run only cancels older runs in the same concurrency group."
@@ -89,13 +92,20 @@ jobs:
    name: Typos
    if: github.event_name != 'pull_request' || github.event.action != 'closed'
    runs-on: ubuntu-latest
+    timeout-minutes: 10
    steps:
      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
      - name: Typos check with custom config file
        uses: crate-ci/typos@37bb98842b0d8c4ffebdb75301a13db0267cef89 # master

  # Fast, compile-free checks that fail early so contributors get feedback in
  # ~1 minute instead of waiting for the full test job.
+  #
+  # These steps are mirrored byte-for-byte in ci-docs-only.yml so that a mixed
+  # PR, which reports two check runs named "Quick Checks", cannot get one red
+  # and one green. Edit both jobs together.
  quick-checks:
    name: Quick Checks
    if: github.event_name != 'pull_request' || github.event.action != 'closed'
@@ -104,6 +114,8 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Install ripgrep
        run: sudo apt-get update && sudo apt-get install -y ripgrep
@@ -137,24 +149,48 @@ jobs:
      - name: Check no planning docs committed
        run: ./scripts/check_no_planning_docs.sh

+      - name: Check CI paths stay in sync
+        run: ./scripts/check_ci_paths_sync.sh
+
+      - name: Check io_uring lane --lib precondition
+        run: ./scripts/check_uring_lane_lib_only.sh
+
  test-and-lint:
    name: Test and Lint
    if: github.event_name != 'pull_request' || github.event.action != 'closed'
+    needs: [ quick-checks ]
    runs-on: sm-standard-4
    timeout-minutes: 90
+    # Both lines are required. Job-level `permissions` replaces the workflow
+    # block rather than merging with it, so declaring only `actions: write`
+    # would drop `contents: read` and break this job's checkout and the
+    # repo-token the setup action hands to setup-protoc.
+    permissions:
+      contents: read
+      actions: write
    env:
      FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: "true"
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          # This job's token can cancel runs and delete Actions caches. Checkout
+          # otherwise writes it into .git/config, where a PR's own build.rs or
+          # proc-macro could read it back out.
+          persist-credentials: false

      - name: Setup Rust environment
        uses: ./.github/actions/setup
        with:
          rust-version: stable
-          cache-shared-key: ci-test
-          github-token: ${{ secrets.GITHUB_TOKEN }}
-          cache-save-if: ${{ github.ref == 'refs/heads/main' }}
+          # Every lane in this workflow reads its cache and none writes it.
+          # cache-warm.yml is the sole writer for all four keys: this workflow
+          # cancels superseded runs on main, and a cancelled run never reaches
+          # rust-cache's post step, so writing from here saved nothing (12 of 15
+          # consecutive main-push runs were cancelled). See rustfs/backlog#1600.
+          cache-shared-key: ci-dev
+          cache-save-if: 'false'
+          install-build-packaging-tools: 'false'

      - name: Prepare test evidence
        run: |
@@ -169,43 +205,54 @@ jobs:
      # Clippy runs before the test pass: lint failures are the most common
      # CI-only breakage and should surface in minutes, not after 20+ minutes
      # of tests.
+      # Sampled too: clippy is the natural control arm for any CARGO_BUILD_JOBS
+      # experiment, since --all-targets is check-only for workspace members and
+      # never links the ~100 test binaries the limit exists to throttle.
      - name: Run clippy lints
-        run: cargo clippy --all-targets -- -D warnings
+        run: |
+          ./scripts/ci/resource_sampler.sh start clippy
+          trap './scripts/ci/resource_sampler.sh stop' EXIT
+          cargo clippy --all-targets -- -D warnings

      - name: Run nextest tests
        env:
-          # Three concurrent workspace test links saturate the self-hosted
-          # runner's overlay I/O and can wedge Cargo until the 75m timeout.
-          CARGO_BUILD_JOBS: "2"
+          # #5394 mitigation, now under a measured experiment (backlog#1601).
+          #
+          # 2 was chosen when three concurrent workspace test links were believed
+          # to saturate the runner's overlay I/O and wedge Cargo until the 75m
+          # timeout. cgroup v2 readings from the sampler show the pod actually
+          # has 14 CPUs and 28GB (peak use 2.1GB), so 2 throttles compilation to
+          # a seventh of what is available and memory was never the constraint —
+          # the label name "sm-standard-4" had led everyone, including the
+          # original mitigation, to assume 4 cores.
+          #
+          # Raised to 3 on main pushes and manual dispatches; PRs keep 2 so the
+          # merge path is untouched while the experiment runs.
+          #
+          # Dispatch is included because push alone cannot supply the samples:
+          # this workflow cancels superseded runs on main, and only 4 of the last
+          # 20 push-triggered Test and Lint jobs reached a terminal state — at
+          # that rate ten samples would take roughly fifty merges. The
+          # concurrency group is scoped by event_name, so a dispatched run has
+          # its own group and is not cancelled by merge traffic, which makes the
+          # sample collectable on demand rather than by waiting.
+          #
+          # Baseline over 17 samples at 2:
+          # median nextest/clippy step ratio 1.95, spread 1.85-2.06. The gate-2
+          # criterion is that ratio dropping at least 10% (below ~1.76) with no
+          # 75m timeout and no run showing three consecutive samples of
+          # rustc/collect2/rust-lld in D state. If it does not, the conclusion is
+          # "this limit is not the bottleneck" — fix it back at 2 and record the
+          # experiment, which is a result, not a failure.
+          #
+          # Must stay step-level: rust-cache hashes CARGO/CC/CFLAGS/CXX/CMAKE/RUST
+          # prefixed variables from process.env into the cache key, so promoting
+          # this to job level would rotate every key on this lane.
+          CARGO_BUILD_JOBS: ${{ (github.event_name == 'push' || github.event_name == 'workflow_dispatch') && '3' || '2' }}
        run: |
          mkdir -p artifacts/test-and-lint
-          # Evidence sampler for issue #5394: the post-mortem pgrep below runs
-          # only after `timeout` has already TERM'd the whole cargo process
-          # group, so it cannot name a wedged process. Sample system and
-          # process state every 60s instead; the last samples before the
-          # timeout show what was stuck (rustc, linker, build script, memory
-          # pressure, ...). The log rides along in the existing artifact.
-          (
-            while true; do
-              {
-                echo "=== $(date --utc --iso-8601=seconds)"
-                echo "--- load";  cat /proc/loadavg
-                echo "--- psi";   grep -H . /proc/pressure/* 2>/dev/null || true
-                echo "--- mem";   free -m
-                echo "--- disk";  df -h / /home/runner 2>/dev/null || df -h /
-                echo "--- top-rss"
-                ps -eo pid,ppid,stat,etime,rss,pcpu,args --sort=-rss | head -15
-                echo "--- build/test processes"
-                ps -eo pid,ppid,stat,etime,rss,pcpu,args | grep -E '[c]argo|[r]ustc|[n]extest|[c]ollect2|rust-ll[d]|[b]uild-script|deps[/]' || true
-                echo "--- d-state (uninterruptible IO)"
-                ps -eo pid,stat,etime,args | awk 'NR > 1 && $2 ~ /D/' || true
-                echo
-              } >> artifacts/test-and-lint/sampler.log 2>&1 || true
-              sleep 60
-            done
-          ) &
-          sampler_pid=$!
-          trap 'kill "${sampler_pid}" 2>/dev/null || true' EXIT
+          ./scripts/ci/resource_sampler.sh start nextest
+          trap './scripts/ci/resource_sampler.sh stop' EXIT
          set +e
          NEXTEST_HIDE_PROGRESS_BAR=1 timeout --verbose --signal=TERM --kill-after=30s 75m \
            cargo nextest run --profile ci --all --exclude e2e_test \
@@ -277,6 +324,48 @@ jobs:
      - name: Run rebalance/decommission migration proofs
        run: ./scripts/check_migration_gate_count.sh

+      # Early stop. Once this job has failed the PR cannot merge, so the sibling
+      # lanes are burning runners on a result nobody can act on: on run
+      # 30674613104 three lanes had already failed while Test and Lint and the
+      # rio-v2 variant kept going past 70 minutes.
+      #
+      # Only this job may cancel. The lanes that are NOT required checks
+      # (protocols, ILM, e2e, s3-tests) must never hold that power: a flake in
+      # one of them would turn the required "Test and Lint" into `cancelled`,
+      # which blocks the merge. Today a maintainer can merge with sftp red, and
+      # that has to stay true.
+      #
+      # These steps run last so the `if: always()` artifact upload above still
+      # captures logs and diagnostics before the run goes away.
+      - name: Annotate early-stop reason
+        if: failure() && github.event_name == 'pull_request'
+        run: |
+          echo "## CI early-stop" >> "$GITHUB_STEP_SUMMARY"
+          echo "Job \`${GITHUB_JOB}\` (Test and Lint) failed; cancelling run ${GITHUB_RUN_ID} to free runners." >> "$GITHUB_STEP_SUMMARY"
+          echo "Sibling jobs showing **cancelled** were stopped by this job, not by their own failure." >> "$GITHUB_STEP_SUMMARY"
+
+      # curl rather than `gh`: every existing `gh` call in this repo runs on
+      # ubuntu-latest, and the sm-standard-* images are custom and trimmed (they
+      # ship no C toolchain, see the e2e job below), so `gh` is not known to
+      # exist here.
+      #
+      # Fork PRs are excluded explicitly instead of relying on the error path:
+      # their GITHUB_TOKEN is forced read-only and job-level permissions cannot
+      # raise it, so the call would always 403. Skipping keeps their logs clean.
+      - name: Cancel run on failure (same-repo PR only)
+        if: >-
+          failure() && github.event_name == 'pull_request'
+          && github.event.pull_request.head.repo.full_name == github.repository
+        continue-on-error: true
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          curl -fsS -X POST \
+            -H "Authorization: Bearer ${GH_TOKEN}" \
+            -H "Accept: application/vnd.github+json" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            "${GITHUB_API_URL}/repos/${GITHUB_REPOSITORY}/actions/runs/${GITHUB_RUN_ID}/cancel" || true
+
  # Dedicated serial lane for the ILM / lifecycle integration tests. These tests
  # drive the object layer through process-global singletons (the GLOBAL_ENV
  # ECStore, the global tier-config manager, background-expiry workers) and bind
@@ -290,6 +379,7 @@ jobs:
  test-ilm-integration-serial:
    name: ILM Integration (serial)
    if: github.event_name != 'pull_request' || github.event.action != 'closed'
+    needs: [ quick-checks ]
    runs-on: sm-standard-4
    timeout-minutes: 45
    env:
@@ -297,14 +387,16 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Setup Rust environment
        uses: ./.github/actions/setup
        with:
          rust-version: stable
-          cache-shared-key: ci-ilm-serial
-          github-token: ${{ secrets.GITHUB_TOKEN }}
-          cache-save-if: ${{ github.ref == 'refs/heads/main' }}
+          cache-shared-key: ci-dev
+          cache-save-if: 'false'
+          install-build-packaging-tools: 'false'

      # test_transition_and_restore_flows was re-enabled by rustfs/backlog#1303:
      # its "missing xl.meta on disk2" was a test-util bug (open_disk hardcoded
@@ -327,6 +419,7 @@ jobs:
  test-and-lint-rio-v2:
    name: Test and Lint (rio-v2)
    if: github.event_name != 'pull_request' || github.event.action != 'closed'
+    needs: [ quick-checks ]
    runs-on: sm-standard-4
    timeout-minutes: 60
    env:
@@ -334,14 +427,16 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Setup Rust environment
        uses: ./.github/actions/setup
        with:
          rust-version: stable
-          cache-shared-key: ci-test-rio-v2
-          github-token: ${{ secrets.GITHUB_TOKEN }}
-          cache-save-if: ${{ github.ref == 'refs/heads/main' }}
+          cache-shared-key: ci-feat-rio
+          cache-save-if: 'false'
+          install-build-packaging-tools: 'false'

      - name: Run rio-v2 clippy lints
        run: cargo clippy -p rustfs -p rustfs-ecstore --all-targets --features rio-v2 -- -D warnings
@@ -354,10 +449,17 @@ jobs:
  test-and-lint-protocols:
    name: "Test and Lint (${{ matrix.features.name }})"
    if: github.event_name != 'pull_request' || github.event.action != 'closed'
+    needs: [ quick-checks ]
    runs-on: sm-standard-4
    timeout-minutes: 60
    strategy:
-      fail-fast: false
+      # On a PR, one failing protocol leg is enough to know the PR is not ready,
+      # so stop the sibling leg instead of paying another ~40 minutes for it.
+      # Everywhere else (main pushes, the merge queue, the weekly schedule) keep
+      # the full signal: there we want to know whether swift AND sftp are broken,
+      # not just whichever failed first. This is the only part of the early-stop
+      # work that also covers fork PRs, since it needs no token.
+      fail-fast: ${{ github.event_name == 'pull_request' }}
      matrix:
        features:
          - name: swift
@@ -369,14 +471,16 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Setup Rust environment
        uses: ./.github/actions/setup
        with:
          rust-version: stable
-          cache-shared-key: ci-test-${{ matrix.features.name }}
-          github-token: ${{ secrets.GITHUB_TOKEN }}
-          cache-save-if: ${{ github.ref == 'refs/heads/main' }}
+          cache-shared-key: ci-feat-proto
+          cache-save-if: 'false'
+          install-build-packaging-tools: 'false'

      - name: Run clippy with ${{ matrix.features.name }}
        run: |
@@ -389,6 +493,7 @@ jobs:
  build-rustfs-debug-binary:
    name: Build RustFS Debug Binary
    if: github.event_name != 'pull_request' || github.event.action != 'closed'
+    needs: [ quick-checks ]
    runs-on: sm-standard-4
    timeout-minutes: 30
    env:
@@ -396,14 +501,16 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Setup Rust environment
        uses: ./.github/actions/setup
        with:
          rust-version: stable
-          cache-shared-key: ci-rustfs-debug-binary
-          cache-save-if: ${{ github.ref == 'refs/heads/main' }}
-          github-token: ${{ secrets.GITHUB_TOKEN }}
+          cache-shared-key: ci-dev
+          cache-save-if: 'false'
+          install-build-packaging-tools: 'false'

      - name: Build debug binary
        run: cargo build -p rustfs --bins --features e2e-test-hooks
@@ -419,6 +526,7 @@ jobs:
  build-rustfs-debug-binary-rio-v2:
    name: Build RustFS Debug Binary (rio-v2)
    if: github.event_name != 'pull_request' || github.event.action != 'closed'
+    needs: [ quick-checks ]
    runs-on: sm-standard-4
    timeout-minutes: 30
    env:
@@ -426,14 +534,16 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Setup Rust environment
        uses: ./.github/actions/setup
        with:
          rust-version: stable
-          cache-shared-key: ci-rustfs-debug-binary-rio-v2
-          cache-save-if: ${{ github.ref == 'refs/heads/main' }}
-          github-token: ${{ secrets.GITHUB_TOKEN }}
+          cache-shared-key: ci-feat-rio
+          cache-save-if: 'false'
+          install-build-packaging-tools: 'false'

      - name: Build debug binary with rio-v2
        run: cargo build -p rustfs --bins --features rio-v2,e2e-test-hooks
@@ -448,6 +558,14 @@ jobs:

  uring-integration:
    name: io_uring Integration (real)
+    # The pull_request trigger includes `closed` purely so the concurrency
+    # group cancels in-flight runs of a closed PR; every other job opts out of
+    # that run with this guard (or is skipped through its `needs` chain). This
+    # job had neither, so each closed/merged PR really ran the whole io_uring
+    # suite (measured 4m17s / 7m19s / 7m31s on runs 30678272341 / 30678117601 /
+    # 30662728539) and kept the cancellation run in progress for minutes.
+    if: github.event_name != 'pull_request' || github.event.action != 'closed'
+    needs: [ quick-checks ]
    # GitHub-hosted ubuntu-latest runs a recent kernel with io_uring and, unlike
    # a container, applies no seccomp filter that would block io_uring_setup — so
    # the probe succeeds and the tests exercise the real UringBackend/FdCache/
@@ -458,17 +576,24 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Setup Rust environment
        uses: ./.github/actions/setup
        with:
          rust-version: stable
+          # Keeps its own key rather than joining ci-dev. rust-cache's key is
+          # built from runner.os/arch plus rustc and lockfile fingerprints — it
+          # does NOT include the runner label or image. ubuntu-latest and
+          # sm-standard-4 are therefore indistinguishable to it, so sharing a key
+          # would let two different system images overwrite each other's
+          # artifacts, and would make a 2-core hosted runner unpack ci-dev's ~3GB
+          # instead of this lane's ~1.3GB. cache-warm.yml warms this key on
+          # ubuntu-latest for the same reason.
          cache-shared-key: ci-uring
-          github-token: ${{ secrets.GITHUB_TOKEN }}
-          cache-save-if: ${{ github.ref == 'refs/heads/main' }}
-
-      - name: Install build dependencies
-        run: sudo apt-get update && sudo apt-get install -y protobuf-compiler
+          cache-save-if: 'false'
+          install-build-packaging-tools: 'false'

      # ext4 supports O_DIRECT; the runner's default TMPDIR may sit on tmpfs or
      # overlayfs, where open(O_DIRECT) returns EINVAL/EOPNOTSUPP and the native
@@ -495,7 +620,17 @@ jobs:
          RUSTFS_IO_URING_READ_ENABLE: "true"
          RUSTFS_URING_TESTS_MUST_RUN: "1"
          TMPDIR: /mnt/rustfs-odirect
-        run: cargo test -p rustfs-ecstore uring_ -- --test-threads=1 --nocapture
+        # --lib narrows what gets compiled, not what gets run: every selected
+        # test lives in the lib target. The 7 integration binaries under
+        # crates/ecstore/tests/ each reported "running 0 tests" here, so they
+        # were compiled and linked for nothing.
+        #
+        # The `uring_` filter must stay exactly as it is. libtest matches on
+        # substring, so it also selects names containing `during_` — 6 of the 18
+        # selected tests are such incidental matches. Narrowing the filter to
+        # `io_uring` would silently drop them, which is a coverage change.
+        # scripts/check_uring_lane_lib_only.sh guards the --lib precondition.
+        run: cargo test -p rustfs-ecstore --lib uring_ -- --test-threads=1 --nocapture

  e2e-tests:
    name: End-to-End Tests
@@ -505,6 +640,8 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      # Full setup with dependency caching: the smoke-suite step below
      # compiles the e2e_test crate, which pulls in most of the workspace.
@@ -513,9 +650,9 @@ jobs:
        uses: ./.github/actions/setup
        with:
          rust-version: stable
-          cache-shared-key: ci-e2e
-          github-token: ${{ secrets.GITHUB_TOKEN }}
-          cache-save-if: ${{ github.ref == 'refs/heads/main' }}
+          cache-shared-key: ci-dev
+          cache-save-if: 'false'
+          install-build-packaging-tools: 'false'

      # Download after the cache restore so the freshly built binary from the
      # build job always wins over anything restored into target/debug.
@@ -589,14 +726,16 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Setup Rust environment
        uses: ./.github/actions/setup
        with:
          rust-version: stable
-          cache-shared-key: ci-e2e
-          github-token: ${{ secrets.GITHUB_TOKEN }}
-          cache-save-if: ${{ github.ref == 'refs/heads/main' }}
+          cache-shared-key: ci-dev
+          cache-save-if: 'false'
+          install-build-packaging-tools: 'false'

      # Download after the cache restore so the freshly built binary from the
      # build job always wins over anything restored into target/debug.
@@ -632,6 +771,8 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Clean up previous test run
        run: |
@@ -686,6 +827,8 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Download debug binary
        uses: actions/download-artifact@37930b1c2abaa49bbe596cd826c3c89aef350131 # v7
@@ -746,12 +889,20 @@ jobs:
  # evaluates ILM within ~2s of the due time, well inside the poll window.
  s3-lifecycle-behavior-tests:
    name: S3 Lifecycle Behavior Tests
-    needs: [ build-rustfs-debug-binary ]
+    # Also gated on e2e-tests, matching s3-implemented-tests: when the e2e smoke
+    # suite is already red this lane cannot tell us anything new, and it holds a
+    # sm-standard-4 for up to 30 minutes doing so. Both lanes only download the
+    # prebuilt debug binary (no cargo build), and s3-implemented-tests — which
+    # already waits on e2e-tests — finishes later anyway, so a green PR's total
+    # wall clock is unchanged.
+    needs: [ build-rustfs-debug-binary, e2e-tests ]
    runs-on: sm-standard-4
    timeout-minutes: 30
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Download debug binary
        uses: actions/download-artifact@37930b1c2abaa49bbe596cd826c3c89aef350131 # v7
@@ -22,11 +22,18 @@ on:
  issue_comment:
    types: [created, edited]

+# Least privilege at the top, widened per job below. This workflow runs on
+# pull_request_target and issue_comment, so it holds full secrets on every fork
+# PR and on any comment anyone writes — the one place in this repository where a
+# compromised action would be handed a repo-write token. It does not check out
+# or execute PR code, so there is no pwn-request path today, but the blast
+# radius should not depend on that staying true.
+#
+# contents: write in particular was never used: the signature records are
+# written to rustfs/cla through the scoped app token created below, and nothing
+# here writes to this repository's contents.
 permissions:
-  contents: write
-  pull-requests: write
-  issues: write
-  checks: write
+  contents: read

 concurrency:
  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.event.issue.number || github.ref }}
@@ -36,14 +43,26 @@ jobs:
  cancel-closed-pr-runs:
    name: Cancel Closed PR Runs
    if: github.event_name == 'pull_request_target' && github.event.action == 'closed'
+    # Echoes one line; the run exists only so the concurrency group cancels the
+    # in-flight run of a closed PR.
+    permissions: {}
    runs-on: ubuntu-latest
+    timeout-minutes: 10
    steps:
      - name: Explain cancellation run
        run: echo "PR closed; this run only cancels older runs in the same concurrency group."

  cla:
    if: ${{ (github.event_name != 'issue_comment' || github.event.issue.pull_request) && (github.event_name != 'pull_request_target' || github.event.action != 'closed') }}
+    # checks: write reports the merge-queue check run; pull-requests and issues
+    # let cla-bot comment and label. contents stays read — see the note above.
+    permissions:
+      contents: read
+      checks: write
+      issues: write
+      pull-requests: write
    runs-on: ubuntu-latest
+    timeout-minutes: 30
    steps:
      - name: Report CLA result for merge queue
        if: github.event_name == 'merge_group'
@@ -62,14 +62,16 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Setup Rust environment
        uses: ./.github/actions/setup
        with:
          rust-version: stable
          cache-shared-key: ci-coverage
-          github-token: ${{ secrets.GITHUB_TOKEN }}
          cache-save-if: ${{ github.ref == 'refs/heads/main' }}
+          install-build-packaging-tools: 'false'

      - name: Install cargo-llvm-cov
        uses: taiki-e/install-action@bffeee26d4db9be238a4ea78d8826604ebcb594d # v2
@@ -116,6 +118,8 @@ jobs:
      issues: write
    steps:
      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
      - name: Open or update failure-tracking issue
        uses: ./.github/actions/schedule-failure-issue
        with:
@@ -82,8 +82,10 @@ jobs:
      github.event_name == 'workflow_dispatch' ||
      (github.event.workflow_run.conclusion == 'success' &&
       github.event.workflow_run.event == 'push' &&
-       github.event.workflow_run.head_branch != 'main')
+       github.event.workflow_run.head_branch != 'main' &&
+       !contains(github.event.workflow_run.head_branch, '-preview'))
    runs-on: ubuntu-latest
+    timeout-minutes: 30
    outputs:
      should_build: ${{ steps.check.outputs.should_build }}
      should_push: ${{ steps.check.outputs.should_push }}
@@ -96,11 +98,18 @@ jobs:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
        with:
+          persist-credentials: false
          # For workflow_run events, checkout the specific commit that triggered the workflow
          ref: ${{ github.event.workflow_run.head_sha || github.sha }}

      - name: Check build conditions
        id: check
+        env:
+          # dispatch inputs via env, not `${{ }}` interpolation: they are
+          # free-form strings and would otherwise be evaluated by bash.
+          INPUT_VERSION: ${{ github.event.inputs.version }}
+          INPUT_PUSH_IMAGES: ${{ github.event.inputs.push_images }}
+          INPUT_FORCE_REBUILD: ${{ github.event.inputs.force_rebuild }}
        run: |
          should_build=false
          should_push=false
@@ -201,9 +210,9 @@ jobs:

          elif [[ "${{ github.event_name }}" == "workflow_dispatch" ]]; then
            # Manual trigger
-            input_version="${{ github.event.inputs.version }}"
+            input_version="$INPUT_VERSION"
            version="${input_version}"
-            should_push="${{ github.event.inputs.push_images }}"
+            should_push="$INPUT_PUSH_IMAGES"
            should_build=true

            # Get short SHA
@@ -211,7 +220,7 @@ jobs:

            echo "🎯 Manual Docker build triggered:"
            echo "   📋 Requested version: $input_version"
-            echo "   🔧 Force rebuild: ${{ github.event.inputs.force_rebuild }}"
+            echo "   🔧 Force rebuild: $INPUT_FORCE_REBUILD"
            echo "   🚀 Push images: $should_push"

            case "$input_version" in
@@ -220,6 +229,13 @@ jobs:
                create_latest=true
                echo "🚀 Building with latest stable release version"
                ;;
+              *-preview*)
+                build_type="preview"
+                is_prerelease=true
+                should_build=false
+                should_push=false
+                echo "⏭️  Preview tags do not publish Docker images"
+                ;;
              # Prerelease versions (must match first, more specific)
              v*alpha*|v*beta*|v*rc*|*alpha*|*beta*|*rc*)
                build_type="prerelease"
@@ -290,6 +306,8 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Login to Docker Hub
        uses: docker/login-action@c94ce9fb468520275223c153574b00df6fe4bcc9 # v3
@@ -325,32 +343,28 @@ jobs:
          CREATE_LATEST="${{ needs.build-check.outputs.create_latest }}"
          VARIANT_SUFFIX="${{ matrix.suffix }}"

-          # Convert version format for Dockerfile compatibility
+          # Convert version format for Dockerfile compatibility. The former
+          # DOCKER_CHANNEL was "release" down every branch and was passed as a
+          # build-arg no Dockerfile declares, so it is gone.
          case "$VERSION" in
            "latest")
-              # For stable latest, use RELEASE=latest + release CHANNEL
              DOCKER_RELEASE="latest"
-              DOCKER_CHANNEL="release"
              ;;
            v*)
              # For versioned releases (v1.0.0), remove 'v' prefix for Dockerfile
              DOCKER_RELEASE="${VERSION#v}"
-              DOCKER_CHANNEL="release"
              ;;
            *)
              # For other versions, pass as-is
              DOCKER_RELEASE="${VERSION}"
-              DOCKER_CHANNEL="release"
              ;;
          esac

          echo "docker_release=$DOCKER_RELEASE" >> "$GITHUB_OUTPUT"
-          echo "docker_channel=$DOCKER_CHANNEL" >> "$GITHUB_OUTPUT"

          echo "🐳 Docker build parameters:"
          echo "  - Original version: $VERSION"
          echo "  - Docker RELEASE: $DOCKER_RELEASE"
-          echo "  - Docker CHANNEL: $DOCKER_CHANNEL"

          # Generate tags based on build type
          # Only support release and prerelease builds (no development builds)
@@ -404,18 +418,24 @@ jobs:
          push: ${{ needs.build-check.outputs.should_push == 'true' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
-          cache-from: |
-            type=gha,scope=docker-${{ matrix.variant }}
-          cache-to: |
-            type=gha,mode=max,scope=docker-${{ matrix.variant }}
+          # No layer cache. This build compiles nothing — it downloads a
+          # release zip and runs apk/apt — so the cache could only save the
+          # minute or two those take, while creating a correctness problem: with
+          # RELEASE=latest the binary URL is resolved by curl *inside* a RUN
+          # layer, and the layer key does not include what that resolved to. A
+          # rebuild at the same RELEASE value (dispatch with version=latest, or
+          # a re-run of the same version) would hit the old layer and ship the
+          # previous release's binary. mode=max also consumed the same 10GB
+          # Actions cache quota the Rust lanes are fighting over.
+          #
+          # Only RELEASE is passed: it is the sole build-arg the Dockerfiles
+          # declare besides TARGETARCH. BUILDTIME, VERSION, BUILD_TYPE, REVISION
+          # and CHANNEL were never read by any stage (and BUILDTIME's $(date ...)
+          # was a literal here, not a shell substitution). BUILD_DATE and VCS_REF
+          # are declared by the Dockerfiles but deliberately left unset —
+          # supplying them would change the published image labels.
          build-args: |
-            BUILDTIME=$(date -u +'%Y-%m-%dT%H:%M:%SZ')
-            VERSION=${{ needs.build-check.outputs.version }}
-            BUILD_TYPE=${{ needs.build-check.outputs.build_type }}
-            REVISION=${{ github.sha }}
            RELEASE=${{ steps.meta.outputs.docker_release }}
-            CHANNEL=${{ steps.meta.outputs.docker_channel }}
-            BUILDKIT_INLINE_CACHE=1
          provenance: true
          sbom: true
          # Add retry mechanism by splitting the build process
@@ -431,6 +451,7 @@ jobs:
    needs: [ build-check, build-docker ]
    if: needs.build-check.outputs.should_build == 'true' && needs.build-check.outputs.should_push == 'true'
    runs-on: ubuntu-latest
+    timeout-minutes: 30
    permissions:
      contents: read
      security-events: write
@@ -485,6 +506,7 @@ jobs:
    needs: [ build-check, build-docker ]
    if: always() && needs.build-check.outputs.should_build == 'true'
    runs-on: ubuntu-latest
+    timeout-minutes: 10
    steps:
      - name: Docker build completion summary
        run: |
@@ -64,14 +64,16 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Setup Rust environment
        uses: ./.github/actions/setup
        with:
          rust-version: stable
          cache-shared-key: ci-e2e-repl
-          github-token: ${{ secrets.GITHUB_TOKEN }}
          cache-save-if: ${{ github.ref == 'refs/heads/main' }}
+          install-build-packaging-tools: 'false'

      # awscurl lets the STS dual-node test actually exercise its path. Without
      # it the test skips gracefully with a visible log line
@@ -124,6 +126,8 @@ jobs:
      issues: write
    steps:
      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
      - name: Open or update failure-tracking issue
        uses: ./.github/actions/schedule-failure-issue
        with:
@@ -45,6 +45,13 @@
 # The PR gate (ci.yml s3-implemented-tests) is unaffected: it avoids Docker
 # via DEPLOY_MODE=binary and defers all pip setup to run.sh's self-bootstrap.

+# DISABLED. This workflow is switched off in the repository's Actions settings
+# (state: disabled_manually) and does not run on any trigger, including its cron
+# and workflow_dispatch. That state lives in GitHub's UI and is invisible when
+# reading this file, which has already misled at least one audit — hence this
+# banner. Re-enabling is a UI action; anyone doing so should first check that the
+# workflow still matches the current CI layout. See rustfs/backlog#1603.
+#
 name: e2e-s3tests

 on:
@@ -135,6 +142,8 @@ jobs:
      TEST_MODE: ${{ matrix.test-mode }}
    steps:
      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      # Provision Python explicitly rather than trusting the runner image to
      # ship a working pip (ci-1: a bare python3 without pip is what broke the
@@ -354,6 +363,8 @@ jobs:
      issues: write
    steps:
      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
      - name: Open or update failure-tracking issue
        uses: ./.github/actions/schedule-failure-issue
        with:
@@ -12,6 +12,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

+# DISABLED. This workflow is switched off in the repository's Actions settings
+# (state: disabled_manually) and does not run on any trigger, including its cron
+# and workflow_dispatch. That state lives in GitHub's UI and is invisible when
+# reading this file, which has already misled at least one audit — hence this
+# banner. Re-enabling is a UI action; anyone doing so should first check that the
+# workflow still matches the current CI layout. See rustfs/backlog#1603.
+#
 name: Fuzz

 on:
@@ -59,6 +66,7 @@ jobs:
    name: Cancel Closed PR Runs
    if: github.event_name == 'pull_request' && github.event.action == 'closed'
    runs-on: ubuntu-latest
+    timeout-minutes: 10
    steps:
      - name: Explain cancellation run
        run: echo "PR closed; this run only cancels older runs in the same concurrency group."
@@ -79,13 +87,14 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Setup Rust environment
        uses: ./.github/actions/setup
        with:
          rust-version: nightly
          cache-shared-key: fuzz-${{ hashFiles('fuzz/Cargo.lock') }}
-          github-token: ${{ secrets.GITHUB_TOKEN }}
          cache-save-if: ${{ github.ref == 'refs/heads/main' || github.event_name == 'schedule' }}

      - name: Install cargo-fuzz
@@ -145,6 +154,8 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Download prebuilt fuzz binaries
        uses: actions/download-artifact@37930b1c2abaa49bbe596cd826c3c89aef350131 # v7
@@ -200,6 +211,8 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Download prebuilt fuzz binaries
        uses: actions/download-artifact@37930b1c2abaa49bbe596cd826c3c89aef350131 # v7
@@ -247,6 +260,8 @@ jobs:
      issues: write
    steps:
      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
      - name: Open or update failure-tracking issue
        uses: ./.github/actions/schedule-failure-issue
        with:
@@ -32,12 +32,14 @@ permissions:
 jobs:
  build-helm-package:
    runs-on: ubuntu-latest
+    timeout-minutes: 30
    if: |
-      github.event_name == 'workflow_dispatch' ||
+      (github.event_name == 'workflow_dispatch' && !contains(github.event.inputs.version, '-preview')) ||
      (
        github.event.workflow_run.conclusion == 'success' &&
        github.event.workflow_run.event == 'push' &&
-        contains(github.event.workflow_run.head_branch, '.')
+        contains(github.event.workflow_run.head_branch, '.') &&
+        !contains(github.event.workflow_run.head_branch, '-preview')
      )

    outputs:
@@ -48,16 +50,26 @@ jobs:
    steps:
      - name: Checkout helm chart repo
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

+      # Both inputs reach the shell through env rather than `${{ }}`
+      # interpolation. A git ref name may contain `$(...)` — anything without a
+      # space is a legal tag — and interpolation pastes it into the script
+      # verbatim, where bash would run it. Reading "$RAW_INPUT" instead makes it
+      # data.
      - name: Normalize release version
        id: version
+        env:
+          RAW_INPUT: ${{ github.event.inputs.version }}
+          RAW_BRANCH: ${{ github.event.workflow_run.head_branch }}
        run: |
          set -eux

          if [ "${{ github.event_name }}" = "workflow_dispatch" ]; then
-            RAW="${{ github.event.inputs.version }}"
+            RAW="$RAW_INPUT"
          else
-            RAW="${{ github.event.workflow_run.head_branch }}"
+            RAW="$RAW_BRANCH"
          fi

          case "$RAW" in
@@ -72,10 +84,13 @@ jobs:
          ./scripts/helm_chart_version.sh "$RAW_TAG"

      - name: Replace chart version and app version
+        env:
+          CHART_VERSION: ${{ steps.version.outputs.chart_version }}
+          APP_VERSION: ${{ steps.version.outputs.app_version }}
        run: |
          set -eux
-          sed -i -E 's/^version:.*/version: "${{ steps.version.outputs.chart_version }}"/' helm/rustfs/Chart.yaml
-          sed -i -E 's/^appVersion:.*/appVersion: "${{ steps.version.outputs.app_version }}"/' helm/rustfs/Chart.yaml
+          sed -i -E "s/^version:.*/version: \"${CHART_VERSION}\"/" helm/rustfs/Chart.yaml
+          sed -i -E "s/^appVersion:.*/appVersion: \"${APP_VERSION}\"/" helm/rustfs/Chart.yaml

      - name: Set up Helm
        uses: azure/setup-helm@b9e51907a09c216f16ebe8536097933489208112 # v4.3.0
@@ -100,6 +115,7 @@ jobs:

  publish-helm-package:
    runs-on: ubuntu-latest
+    timeout-minutes: 30
    needs: [ build-helm-package ]
    if: needs.build-helm-package.result == 'success'

@@ -107,6 +123,8 @@ jobs:
      - name: Checkout helm package repo
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
        with:
+          # persist-credentials-exempt: this checkout's token IS the push credential —
+          # the job git-pushes to rustfs/helm below. Clearing it breaks chart publishing.
          repository: rustfs/helm
          token: ${{ secrets.RUSTFS_HELM_PACKAGE }}

@@ -122,11 +140,19 @@ jobs:
      - name: Generate index
        run: helm repo index . --url https://charts.rustfs.com

+      # app_version is derived from the triggering tag name, and this job holds
+      # the cross-repository push token with rustfs/helm already checked out —
+      # the worst place in the repo to paste an attacker-influenced string into
+      # a shell line. Passed through env so bash treats it as data.
      - name: Push helm package and index file
+        env:
+          GIT_USERNAME: ${{ secrets.USERNAME }}
+          GIT_EMAIL: ${{ secrets.EMAIL_ADDRESS }}
+          APP_VERSION: ${{ needs.build-helm-package.outputs.app_version }}
        run: |
          set -eux
-          git config --global user.name "${{ secrets.USERNAME }}"
-          git config --global user.email "${{ secrets.EMAIL_ADDRESS }}"
+          git config --global user.name "${GIT_USERNAME}"
+          git config --global user.email "${GIT_EMAIL}"
          git add .
-          git commit -m "Update rustfs helm package with ${{ needs.build-helm-package.outputs.app_version }}." || echo "No changes to commit"
+          git commit -m "Update rustfs helm package with ${APP_VERSION}." || echo "No changes to commit"
          git push origin main
@@ -12,6 +12,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

+# DISABLED. This workflow is switched off in the repository's Actions settings
+# (state: disabled_manually) and does not run on any trigger, including its cron
+# and workflow_dispatch. That state lives in GitHub's UI and is invisible when
+# reading this file, which has already misled at least one audit — hence this
+# banner. Re-enabling is a UI action; anyone doing so should first check that the
+# workflow still matches the current CI layout. See rustfs/backlog#1603.
+#
 name: "issue-translator"
 on:
  issue_comment:
@@ -26,6 +33,7 @@ permissions:
 jobs:
  build:
    runs-on: ubuntu-latest
+    timeout-minutes: 10
    steps:
      - uses: usthe/issues-translate-action@b41f55ddc81d7d54bd542a4f289fe28ec081898e # v2.7
        with:
@@ -23,6 +23,13 @@
 # Runner: GitHub-hosted `ubuntu-latest`. It reliably ships Docker + Python,
 # unlike the self-hosted fleet, whose pods drift in Docker/pip availability
 # (see the infra note in e2e-s3tests.yml). Nightly + manual only.
+# DISABLED. This workflow is switched off in the repository's Actions settings
+# (state: disabled_manually) and does not run on any trigger, including its cron
+# and workflow_dispatch. That state lives in GitHub's UI and is invisible when
+# reading this file, which has already misled at least one audit — hence this
+# banner. Re-enabling is a UI action; anyone doing so should first check that the
+# workflow still matches the current CI layout. See rustfs/backlog#1603.
+#
 name: minio-interop

 on:
@@ -51,13 +58,14 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Setup Rust environment
        uses: ./.github/actions/setup
        with:
          rust-version: stable
          cache-shared-key: ci-minio-interop
-          github-token: ${{ secrets.GITHUB_TOKEN }}
          cache-save-if: ${{ github.ref == 'refs/heads/main' }}

      - name: Generate real MinIO fixtures via Docker
@@ -45,6 +45,13 @@
 # docker-capable self-hosted `dind-sm-standard-2` label was the alternative but
 # has fewer cores and reintroduces fleet-state risk for no reliability gain.

+# DISABLED. This workflow is switched off in the repository's Actions settings
+# (state: disabled_manually) and does not run on any trigger, including its cron
+# and workflow_dispatch. That state lives in GitHub's UI and is invisible when
+# reading this file, which has already misled at least one audit — hence this
+# banner. Re-enabling is a UI action; anyone doing so should first check that the
+# workflow still matches the current CI layout. See rustfs/backlog#1603.
+#
 name: mint

 on:
@@ -118,6 +125,8 @@ jobs:
    timeout-minutes: 120
    steps:
      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Enable buildx
        uses: docker/setup-buildx-action@8d2750c68a42422c14e847fe6c8ac0403b4cbd6f # v3
@@ -263,6 +272,8 @@ jobs:
      issues: write
    steps:
      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
      - name: Open or update failure-tracking issue
        uses: ./.github/actions/schedule-failure-issue
        with:
@@ -0,0 +1,57 @@
+# Copyright 2024 RustFS Team
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name: Nightly GNU Build
+
+on:
+  schedule:
+    - cron: "0 0 * * *"
+      timezone: "Asia/Shanghai"
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: nightly-gnu-build-main-${{ github.event_name }}
+  cancel-in-progress: ${{ github.event_name == 'workflow_dispatch' }}
+
+env:
+  CARGO_TERM_COLOR: always
+  RUST_BACKTRACE: 1
+
+jobs:
+  build:
+    name: Build x86_64 GNU
+    runs-on: sm-standard-2
+    timeout-minutes: 150
+    env:
+      FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: "true"
+    steps:
+      - name: Checkout main branch
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
+          ref: main
+
+      - name: Setup Rust environment
+        uses: ./.github/actions/setup
+        with:
+          cache-shared-key: build-x86_64-unknown-linux-gnu
+          cache-save-if: 'false'
+          install-build-packaging-tools: 'false'
+          install-test-tools: 'false'
+
+      - name: Build RustFS
+        run: cargo build --release --locked --target x86_64-unknown-linux-gnu -p rustfs --bins
@@ -19,9 +19,12 @@ on:
  schedule:
    - cron: '0 5 * * 0' # Weekly on Sunday 05:00 UTC (staggered after the midnight ci/build crons)

+# GITHUB_TOKEN only needs to read the repository here: the branch push and the
+# pull request are both created by update-flake-lock using the
+# FLAKE_UPDATE_TOKEN PAT below, not by this token. Leaving write on it hands a
+# repo-write credential to an unattended weekly job that does not use it.
 permissions:
-  contents: write
-  pull-requests: write
+  contents: read

 concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
@@ -37,6 +40,10 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        # persist-credentials-exempt: update-flake-lock pushes the branch and opens
+        # the PR. It passes FLAKE_UPDATE_TOKEN to create-pull-request itself rather
+        # than reusing .git/config, but that is unverified — exempt until a
+        # workflow_dispatch run confirms it (rustfs/backlog#1602).

      - name: Install Nix
        uses: DeterminateSystems/determinate-nix-action@629b284231c2a82554b724e357e47fc6020833c8 # v3
@@ -12,6 +12,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

+# DISABLED. This workflow is switched off in the repository's Actions settings
+# (state: disabled_manually) and does not run on any trigger, including its cron
+# and workflow_dispatch. That state lives in GitHub's UI and is invisible when
+# reading this file, which has already misled at least one audit — hence this
+# banner. Re-enabling is a UI action; anyone doing so should first check that the
+# workflow still matches the current CI layout. See rustfs/backlog#1603.
+#
 name: Nix CI

 on:
@@ -46,6 +53,7 @@ jobs:
    name: Cancel Closed PR Runs
    if: github.event_name == 'pull_request' && github.event.action == 'closed'
    runs-on: ubuntu-latest
+    timeout-minutes: 10
    steps:
      - name: Explain cancellation run
        run: echo "PR closed; this run only cancels older runs in the same concurrency group."
@@ -63,6 +71,8 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Install Nix
        uses: DeterminateSystems/determinate-nix-action@4eea0b33e3d1f02ecfe37cf16e7204c424009606 # v3.21.0
@@ -22,6 +22,13 @@
 # a deliberate correctness cost (e.g. the #4221 fsync durability fix) is
 # recorded but does not block (rustfs/backlog#935 correction 1).

+# DISABLED. This workflow is switched off in the repository's Actions settings
+# (state: disabled_manually) and does not run on any trigger, including its cron
+# and workflow_dispatch. That state lives in GitHub's UI and is invisible when
+# reading this file, which has already misled at least one audit — hence this
+# banner. Re-enabling is a UI action; anyone doing so should first check that the
+# workflow still matches the current CI layout. See rustfs/backlog#1603.
+#
 name: Performance A/B

 on:
@@ -92,6 +99,8 @@ jobs:
    steps:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false

      - name: Setup Rust environment
        uses: ./.github/actions/setup
@@ -99,7 +108,6 @@ jobs:
          rust-version: stable
          cache-shared-key: warp-ab-${{ hashFiles('**/Cargo.lock') }}
          cache-save-if: ${{ github.ref == 'refs/heads/main' }}
-          github-token: ${{ secrets.GITHUB_TOKEN }}

      - name: Build release rustfs
        run: cargo build --release --bin rustfs
@@ -142,6 +150,7 @@ jobs:
      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
        with:
+          persist-credentials: false
          fetch-depth: 0 # baseline is built from origin/main

      - name: Setup Rust environment
@@ -150,7 +159,6 @@ jobs:
          rust-version: stable
          cache-shared-key: warp-ab-${{ hashFiles('**/Cargo.lock') }}
          cache-save-if: ${{ github.ref == 'refs/heads/main' }}
-          github-token: ${{ secrets.GITHUB_TOKEN }}

      - name: Install warp
        run: |
@@ -162,13 +170,15 @@ jobs:

      - name: Decide exemption
        id: exempt
+        env:
+          INPUT_ALLOW_REGRESSION: ${{ github.event.inputs.allow_regression }}
        run: |
          allow="false"
          if [[ "${{ github.event_name }}" == "pull_request" ]] \
            && ${{ contains(github.event.pull_request.labels.*.name, 'perf-deliberate-tradeoff') }}; then
            allow="true"
          fi
-          if [[ "${{ github.event.inputs.allow_regression }}" == "true" ]]; then
+          if [[ "$INPUT_ALLOW_REGRESSION" == "true" ]]; then
            allow="true"
          fi
          echo "allow_regression=$allow" >> "$GITHUB_OUTPUT"
@@ -215,8 +225,34 @@ jobs:
          cp target/release/rustfs baseline-bin/rustfs
          echo "built=true" >> "$GITHUB_OUTPUT"

+      - name: Build baseline on cache miss (different candidate)
+        id: baseline_build
+        if: >-
+          steps.baseline_cache.outputs.cache-hit != 'true' &&
+          steps.commits.outputs.baseline_sha != steps.commits.outputs.candidate_sha
+        run: |
+          set -euo pipefail
+          baseline_root="$RUNNER_TEMP/rustfs-baseline-${{ github.run_id }}"
+          baseline_target="$RUNNER_TEMP/rustfs-baseline-target-${{ github.run_id }}"
+          git worktree add --detach "$baseline_root" "${{ steps.commits.outputs.baseline_sha }}"
+          cargo build --release --manifest-path "$baseline_root/Cargo.toml" --bin rustfs --target-dir "$baseline_target"
+          mkdir -p baseline-bin
+          cp "$baseline_target/release/rustfs" baseline-bin/rustfs
+          git worktree remove --force "$baseline_root"
+          echo "built=true" >> "$GITHUB_OUTPUT"
+
+      - name: Build candidate binary
+        id: candidate_build
+        if: steps.commits.outputs.baseline_sha != steps.commits.outputs.candidate_sha
+        run: |
+          set -euo pipefail
+          cargo build --release --bin rustfs
+          mkdir -p candidate-bin
+          cp target/release/rustfs candidate-bin/rustfs
+          echo "built=true" >> "$GITHUB_OUTPUT"
+
      - name: Save self-healed baseline to cache
-        if: steps.selfheal.outputs.built == 'true'
+        if: steps.selfheal.outputs.built == 'true' || steps.baseline_build.outputs.built == 'true'
        uses: actions/cache/save@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6
        with:
          path: baseline-bin/rustfs
@@ -224,54 +260,58 @@ jobs:

      - name: Run warp A/B and gate
        id: ab
+        env:
+          INPUT_DURATION: ${{ github.event.inputs.duration }}
        run: |
          set -euo pipefail
-          # Budget note: with perf-3's cached baseline the nightly does no source
-          # build on a cache hit, so the wall-clock is dominated by the short warp
-          # matrix — duration/rounds/cooldown are kept small to fit all 24 cells
-          # (6 workloads x 2 phases x 2 drive-sync) rather than dropping cells.
+          # The formal runner executes A1 baseline -> B1 candidate -> B2 candidate
+          # -> A2 baseline for each workload and drive-sync cell. It requires three
+          # rounds per leg to emit tail latency and error-rate evidence.
          # --health-timeout 180 outlasts the server's own 120s startup-readiness
          # budget, which the rig's previous 60s health poll undershot (the first
          # two nightly failures). perf-6 recalibrates these once the noise study
          # lands.
-          duration="${{ github.event.inputs.duration || '12s' }}"
+          duration="${INPUT_DURATION:-12s}"
          baseline_sha="${{ steps.commits.outputs.baseline_sha }}"
          candidate_sha="${{ steps.commits.outputs.candidate_sha }}"
          baseline_hit="${{ steps.baseline_cache.outputs.cache-hit }}"
          selfheal_built="${{ steps.selfheal.outputs.built }}"
+          baseline_built="${{ steps.baseline_build.outputs.built }}"
+          candidate_built="${{ steps.candidate_build.outputs.built }}"

-          args=(--duration "$duration" --rounds 2 --cooldown 5 --health-timeout 180)
+          args=(--duration "$duration" --rounds 3 --cooldown 5 --health-timeout 180 --baseline-revision "$baseline_sha" --candidate-revision "$candidate_sha")

-          if [[ "$baseline_hit" == "true" || "$selfheal_built" == "true" ]]; then
+          if [[ "$baseline_hit" == "true" || "$selfheal_built" == "true" || "$baseline_built" == "true" ]]; then
            chmod +x baseline-bin/rustfs
            base_bin="$PWD/baseline-bin/rustfs"
            args+=(--baseline-bin "$base_bin")
            if [[ "$baseline_hit" == "true" ]]; then
              base_src="actions-cache (rustfs-baseline-$baseline_sha)"
-            else
+            elif [[ "$selfheal_built" == "true" ]]; then
              base_src="source build (cache self-heal, saved as rustfs-baseline-$baseline_sha)"
+            else
+              base_src="isolated origin/main source build (saved as rustfs-baseline-$baseline_sha)"
            fi
            if [[ "$candidate_sha" == "$baseline_sha" ]]; then
              # Nightly on main: the candidate is the same commit as the baseline,
              # so reuse the one binary for both phases and skip all builds.
-              args+=(--candidate-bin "$base_bin" --skip-build)
+              args+=(--candidate-bin "$base_bin")
              cand_src="same binary as baseline (same commit)"
-            else
+            elif [[ "$candidate_built" == "true" ]]; then
+              chmod +x candidate-bin/rustfs
+              args+=(--candidate-bin "$PWD/candidate-bin/rustfs")
              cand_src="source build of the checked-out ref"
+            else
+              echo "::error::candidate binary was not built" >&2
+              exit 2
            fi
          else
-            # Cache miss with candidate != baseline (opt-in PR gate only): fall
-            # back to the source double-build. With the post-#4806 LTO profile
-            # this will overrun the job budget and alert; rerun once the push
-            # cache build for origin/main has completed, or wait for perf-7's
-            # merge-base caching.
-            args+=(--baseline-ref origin/main)
-            base_src="source build of origin/main (cache miss)"
-            cand_src="source build of the checked-out ref"
+            echo "::error::baseline binary was not restored or built" >&2
+            exit 2
          fi

-          args+=(--provenance-note "baseline commit: $baseline_sha - $base_src")
-          args+=(--provenance-note "candidate commit: $candidate_sha - $cand_src")
+          echo "baseline binary: $base_src"
+          echo "candidate binary: $cand_src"

          if [[ "${{ steps.exempt.outputs.allow_regression }}" == "true" ]]; then
            args+=(--allow-regression --exemption-reason "labeled perf-deliberate-tradeoff / dispatch override")
@@ -279,7 +319,7 @@ jobs:
          # Do not let a gate FAIL abort the job here; capture status and surface
          # it after the PR comment is posted.
          set +e
-          bash scripts/run_hotpath_warp_ab.sh "${args[@]}"
+          bash scripts/run_hotpath_warp_abba.sh "${args[@]}"
          echo "status=$?" >> "$GITHUB_OUTPUT"
          set -e
          # Locate the newest run dir + gate.md for the summary/comment/artifact
@@ -287,10 +327,10 @@ jobs:
          # holds server-logs/ for diagnosis.
          # Run dirs are UTC-timestamp names (no special chars); ls is safe here.
          # shellcheck disable=SC2012
-          run_dir="$(ls -td target/hotpath-ab/*/ 2>/dev/null | head -n1 || true)"
+          run_dir="$(ls -td target/hotpath-abba/*/ 2>/dev/null | head -n1 || true)"
          echo "run_dir=${run_dir%/}" >> "$GITHUB_OUTPUT"
          # shellcheck disable=SC2012
-          gate_md="$(ls -t target/hotpath-ab/*/gate.md 2>/dev/null | head -n1 || true)"
+          gate_md="$(ls -t target/hotpath-abba/*/candidate_gate.md 2>/dev/null | head -n1 || true)"
          echo "gate_md=$gate_md" >> "$GITHUB_OUTPUT"

      - name: Upload A/B results
@@ -298,10 +338,10 @@ jobs:
        uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6
        with:
          name: hotpath-warp-ab-${{ github.run_number }}
-          # Includes per-cell median_summary.csv / baseline_compare.csv, gate.md,
+          # Includes per-cell median_summary.csv / baseline_compare.csv, both gates,
          # and server-logs/ (rustfs.log + startup env per phase) so a failed run
          # is diagnosable. Short retention: this is churny nightly debug data.
-          path: target/hotpath-ab/
+          path: target/hotpath-abba/
          if-no-files-found: warn
          retention-days: 14

@@ -385,6 +425,8 @@ jobs:
      issues: write
    steps:
      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
      - name: Open or update failure-tracking issue
        uses: ./.github/actions/schedule-failure-issue
        with:
@@ -0,0 +1,81 @@
+# Copyright 2026 RustFS Team
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Asserts that the self-hosted runners are still ephemeral — one job per pod.
+#
+# This repository is public and its pull_request jobs run on those runners,
+# executing the PR's own build.rs, proc-macros and tests. The only thing keeping
+# that code from reaching a later job is that each ARC pod handles exactly one
+# job and is then destroyed. That guarantee lives in the ARC scale-set
+# configuration, outside this repository, where it can be changed without any PR
+# — so it is asserted here from the outside, against real run data, instead of
+# being assumed.
+#
+# Monthly rather than per-PR: the property changes only when someone
+# reconfigures the scale set, and the check costs a few dozen API calls.
+# See docs/ci/runners.md and rustfs/backlog#1602.
+
+name: Runner Hygiene
+
+on:
+  schedule:
+    - cron: "0 6 1 * *" # Monthly, 1st at 06:00 UTC (after the daily audit cron)
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: runner-hygiene
+  cancel-in-progress: false
+
+jobs:
+  check-ephemerality:
+    name: Check runner ephemerality
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
+
+      # Exit 2 (inconclusive / broken) is deliberately not a pass: a window
+      # where every sm-* job was still queued would otherwise look identical to
+      # a clean bill of health.
+      - name: Assert one job per self-hosted runner
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: ./scripts/ci/check_runner_ephemerality.sh 40
+
+  alert-on-failure:
+    name: Alert on scheduled failure
+    needs: [check-ephemerality]
+    # Same ci-8 mechanism as coverage.yml, audit.yml and the nightly lanes:
+    # scheduled runs file a tracking issue, manual dispatch stays quiet so
+    # debugging never produces a spurious alert.
+    if: always() && github.event_name == 'schedule' && contains(needs.*.result, 'failure')
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    permissions:
+      contents: read
+      issues: write
+    steps:
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
+      - name: Open or update failure-tracking issue
+        uses: ./.github/actions/schedule-failure-issue
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
@@ -24,6 +24,13 @@
 # The run itself is expected to end red (the forced failure); only the
 # alert-on-failure job result matters.

+# DISABLED. This workflow is switched off in the repository's Actions settings
+# (state: disabled_manually) and does not run on any trigger, including its cron
+# and workflow_dispatch. That state lives in GitHub's UI and is invisible when
+# reading this file, which has already misled at least one audit — hence this
+# banner. Re-enabling is a UI action; anyone doing so should first check that the
+# workflow still matches the current CI layout. See rustfs/backlog#1603.
+#
 name: Schedule Failure Alert Drill

 on:
@@ -56,6 +63,8 @@ jobs:
      issues: write
    steps:
      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
      - name: Open or update failure-tracking issue
        uses: ./.github/actions/schedule-failure-issue
        with:
@@ -12,6 +12,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

+# DISABLED. This workflow is switched off in the repository's Actions settings
+# (state: disabled_manually) and does not run on any trigger, including its cron
+# and workflow_dispatch. That state lives in GitHub's UI and is invisible when
+# reading this file, which has already misled at least one audit — hence this
+# banner. Re-enabling is a UI action; anyone doing so should first check that the
+# workflow still matches the current CI layout. See rustfs/backlog#1603.
+#
 name: "Mark stale issues"
 on:
  schedule:
@@ -20,6 +27,7 @@ on:
 jobs:
  stale:
    runs-on: ubuntu-latest
+    timeout-minutes: 30
    steps:
      - uses: actions/stale@5bef64f19d7facfb25b37b414482c7164d639639 # v9
        with:
@@ -15,6 +15,7 @@ concurrency:
 jobs:
  update:
    runs-on: ubuntu-latest
+    timeout-minutes: 10
    steps:
      - uses: overtrue/repo-visuals-action@72f34d24769ff5d341956da2f23952594ef2f1e2 # v1.3.0
        with:
@@ -21,6 +21,22 @@ If repo-level instructions conflict, follow the nearest file and keep behavior a
 - Avoid redundant file reads, repeated commands, and unnecessary exploratory work once enough context is available.
 - A good result is a minimal diff with clear assumptions, no over-engineering, and independent verification that survives Adversarial Validation (below).

+## Worktree and Disk Hygiene
+
+- Unless the requester explicitly says otherwise, treat every new implementation task as isolated work: fetch the latest `origin/main`, confirm the requested change is not already present there, and create a dedicated feature branch and worktree from that exact upstream commit before editing. Do not implement new work directly in the primary checkout or reuse a worktree from another task.
+- Check available disk space before creating the worktree or starting dependency downloads, builds, tests, coverage, or other artifact-heavy commands. For long-running or artifact-heavy work, re-check disk usage at natural phase boundaries and before broad validation; if remaining space may not safely accommodate the next command, stop and reclaim task-owned artifacts before continuing.
+- Keep cleanup scoped and safe: remove generated build/test/coverage artifacts and temporary files created by the task when they are no longer needed, and never delete another task's worktree or uncommitted files. Prefer shared dependency caches where supported instead of duplicating large artifacts across worktrees.
+- At handoff, report the disk-space checks, cleanup performed, and any retained worktree or artifacts with the reason they are still needed.
+
+## PR Lifecycle Monitoring
+
+- Creating or updating a PR is not the terminal state. Unless the requester explicitly limits the task to PR creation, monitor the PR through its terminal state: merged, closed, or explicitly handed off because progress requires user or maintainer action.
+- While the task is active, monitor CI/check runs, review decisions and unresolved threads, mergeability and conflicts, and unexpected head/base changes. Prefer event-driven or bounded waits provided by the current environment over frequent polling; report only state changes, actionable failures, or meaningful prolonged delays.
+- Investigate every failing check and review comment before changing code. Fix failures attributable to the task, run the verification required for the new diff, push the update, respond to or resolve the corresponding review threads, and resume monitoring. Do not weaken checks, dismiss valid feedback, or retry flaky failures merely to obtain a green result.
+- Treat opening, green CI, approval, and mergeability as intermediate states. Never merge without the required reviewer approval or explicit authority. If progress depends on credentials, infrastructure, a maintainer decision, or another external action, report the exact blocker and the evidence already collected.
+- If the current execution environment cannot remain active until the next PR event, use a supported automation, monitor, or thread wakeup when available and within scope. Otherwise leave an explicit handoff containing the PR, current state, next event to observe, and pending cleanup; do not imply that background monitoring exists when none is scheduled.
+- After observing a merge, verify the commits are preserved on the upstream base, ensure the worktree is clean, remove the dedicated worktree, prune stale worktree metadata, and delete the local task branch when it is no longer in use. For a closed or abandoned PR, preserve any unmerged work unless deletion was explicitly authorized. Do not delete remote branches unless explicitly requested or repository automation owns that cleanup.
+
 ## Autonomy and Approval Boundaries

 - Inquiry tasks (answer, explain, review, diagnose, plan): report findings; do not change files unless a fix is explicitly requested.
@@ -105,33 +121,78 @@ CI) fails the build if anything is committed under `docs/superpowers/`, even via

 ## Verification Before PR

-Convert changes into independently verifiable outcomes. Prefer focused tests for behavior changes and run the relevant checks before declaring completion.
-Non-exempt changes must also pass Adversarial Validation (next section) before the checks below count as completion.
+Convert changes into independently verifiable outcomes. This section controls
+agent-run local validation; preparing a commit or PR does not by itself require
+the broadest gate. Inspect only the final task-owned diff, classify it by
+behavioral impact rather than line count or path alone, and run the smallest
+set of checks that provides meaningful coverage. Do not let unrelated
+worktree changes or a generic contributor checklist expand the scope.
+Non-exempt changes must also pass Adversarial Validation (next section) before
+the checks below count as completion.

-For code changes, run and pass the following before opening a PR:
+### Validation floor

-```bash
-make pre-pr
-```
+- Every change that is not documentation-only must finish with
+  `cargo fmt --all --check` passing. An umbrella gate that runs this exact
+  check satisfies the requirement; do not run it twice. Use `cargo fmt --all`
+  only when formatting needs to be fixed. Run the configured formatter or
+  validator for other changed languages when one exists.
+- Documentation-only or instruction-only means all task-owned changes are
+  prose or documentation assets and cannot affect runtime, builds, CI,
+  dependencies, generated code, or tests. Run `git diff --check` and any
+  relevant documentation guard, but skip Cargo formatting, compilation,
+  Clippy, tests, `make pre-commit`, and `make pre-pr`.
+- Behavior changes require relevant existing or new tests. Prefer the most
+  focused test or affected package. A passing targeted test can also provide
+  sufficient compilation coverage when it builds every changed target and
+  feature involved; do not add a redundant `cargo check` in that case.
+- `cargo check` supplements compilation coverage; it never substitutes for a
+  behavioral test. If a relevant test cannot reasonably be added or run, use
+  the narrowest compilation check and report the reason and remaining risk.

-Before committing code changes, prefer focused verification for the touched
-surface and use the faster local gate when a broad smoke check is needed:
+### Validation tiers

-```bash
-make pre-commit
-```
+1. **Documentation/instruction-only:** Apply the exemption above. Run a guard
+   such as `make doc-paths-check` only when it is relevant to the edited text.
+2. **Non-behavioral source change:** For comments, formatting, or another
+   demonstrably non-executable change, run the formatting floor. Compilation,
+   Clippy, and tests may be skipped only when the edit cannot affect
+   compilation or runtime behavior; run targeted doctests if executable
+   documentation examples changed.
+3. **Localized or bounded behavior change:** Run the formatting floor and the
+   narrowest relevant tests. Add package-scoped `cargo check` or Clippy only
+   for changed targets, features, APIs, error handling, async behavior, or
+   control flow not already covered. When several crates are affected but the
+   dependency set is identifiable, validate those packages and known
+   dependents instead of the whole workspace. Use `make pre-commit` only when
+   a repository-wide fast gate adds useful confidence beyond those checks.
+4. **Broad or high-risk change:** Run `make pre-pr` only when targeted coverage
+   cannot bound the impact, including:
+   - dependency, feature, build-script, procedural-macro, code-generation,
+     toolchain, or CI changes that alter compilation or the test matrix;
+   - cross-crate public APIs, shared foundational code, or broad refactors with
+     an unbounded dependent set;
+   - locking, storage durability or formats, erasure coding, replication,
+     RPC/protocol compatibility, IAM/KMS/auth, cryptography, or other
+     security-sensitive behavior;
+   - a targeted check that reveals wider impact, an explicit user request, or
+     a release policy that requires the full gate.

-For migration batches, do not run the full `make pre-pr` gate before every
-intermediate commit. Use focused tests and `make pre-commit` during
-development, then reserve `make pre-pr` for the final PR-ready branch.
+Documentation-only and non-behavioral classifications take precedence over
+path-based triggers. A small diff can still be high-risk, while a CI comment,
+manifest comment, or release-note edit does not require full validation.

-Before pushing code changes, make sure formatting is clean:
+`make pre-pr` includes `make pre-commit` coverage. Never run both for the same
+unchanged diff, and do not repeat equivalent checks during PR preparation or
+because a local hook already ran them. Rerun only checks whose scope is affected
+by later edits. Full workspace checks do not replace a relevant integration or
+E2E test for changed behavior; run that focused test when required and
+available, or report why it was not run and the remaining risk.

- Run `cargo fmt --all`.
- Run `cargo fmt --all --check` and ensure no files are modified unexpectedly.
+If `make` is unavailable, run the equivalent checks defined under
+`.config/make/`. At handoff, list the checks actually run, checks intentionally
+skipped, and the reason for the selected tier.

-If `make` is unavailable, run the equivalent checks defined under `.config/make/`.
-Documentation-only or instruction-only changes are exempt from the verification commands above (including the `.config/make/` equivalents), though any locally installed git pre-commit hooks may still run on commit unless explicitly skipped.
 After build-based verification completes, clean generated build artifacts before wrapping up to avoid unnecessary disk usage.
 Do not open a PR with code changes when the required checks fail.
 Make a failing check pass by fixing the cause, never by weakening the gate:
@@ -290,11 +290,11 @@ dependencies = [

 [[package]]
 name = "ar_archive_writer"
-version = "0.5.2"
+version = "0.5.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4087686b4b0a3427190bae57a1d9a478dbb2d40c5dc1bd6e2b6d797913bdd348"
+checksum = "73cd58deff2140a0a8eae87e417bd01db68a33e148aa93d1e8cd837e55e312b6"
 dependencies = [
- "object 0.37.3",
+ "object 0.39.1",
 ]

 [[package]]
@@ -599,6 +599,16 @@ dependencies = [
 "syn 2.0.119",
 ]

+[[package]]
+name = "assert-json-diff"
+version = "2.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "47e4f2b81832e72834d7518d8487a0396a28cc408186a2e8854c0f98011faf12"
+dependencies = [
+ "serde",
+ "serde_json",
+]
+
 [[package]]
 name = "astral-tokio-tar"
 version = "0.6.4"
@@ -943,6 +953,32 @@ dependencies = [
 "uuid",
 ]

+[[package]]
+name = "aws-sdk-kms"
+version = "1.114.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c0b7d906608ee41e7ddea9983577ba82200435644d567d63dc34e822e088b453"
+dependencies = [
+ "arc-swap",
+ "aws-credential-types",
+ "aws-runtime",
+ "aws-smithy-async",
+ "aws-smithy-http",
+ "aws-smithy-json",
+ "aws-smithy-observability",
+ "aws-smithy-runtime",
+ "aws-smithy-runtime-api",
+ "aws-smithy-schema",
+ "aws-smithy-types",
+ "aws-types",
+ "bytes",
+ "fastrand",
+ "http 0.2.12",
+ "http 1.5.0",
+ "regex-lite",
+ "tracing",
+]
+
 [[package]]
 name = "aws-sdk-s3"
 version = "1.140.0"
@@ -1158,17 +1194,23 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "635d23afda0a6ab48d666c4d447c4873e8d1e83518a2be2093122397e50b838e"
 dependencies = [
 "aws-smithy-async",
+ "aws-smithy-protocol-test",
 "aws-smithy-runtime-api",
 "aws-smithy-types",
+ "bytes",
 "h2",
 "http 1.5.0",
+ "http-body 1.1.0",
 "hyper",
 "hyper-rustls",
 "hyper-util",
+ "indexmap 2.14.0",
 "pin-project-lite",
 "rustls",
 "rustls-native-certs",
 "rustls-pki-types",
+ "serde",
+ "serde_json",
 "tokio",
 "tokio-rustls",
 "tower",
@@ -1195,6 +1237,25 @@ dependencies = [
 "aws-smithy-runtime-api",
 ]

+[[package]]
+name = "aws-smithy-protocol-test"
+version = "0.64.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f76511a0e223ce78deb6a78b8afebda99cb737cfbc8a58d96dcb190f012dd40a"
+dependencies = [
+ "assert-json-diff",
+ "aws-smithy-runtime-api",
+ "base64-simd",
+ "cbor-diag",
+ "ciborium",
+ "http 0.2.12",
+ "pretty_assertions",
+ "regex-lite",
+ "roxmltree",
+ "serde_json",
+ "thiserror 2.0.19",
+]
+
 [[package]]
 name = "aws-smithy-query"
 version = "0.62.0"
@@ -1679,9 +1740,9 @@ dependencies = [

 [[package]]
 name = "bytesize"
-version = "2.4.2"
+version = "2.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3d7c8918969267b2932ffd5655509bbbea0833823058c378876953217f5fc50e"
+checksum = "351a3e803ee3c6eaeee6b00076b767514b37c32a73d326c3ec7abddb7d6c3493"

 [[package]]
 name = "bytestring"
@@ -1758,6 +1819,25 @@ dependencies = [
 "cipher 0.5.2",
 ]

+[[package]]
+name = "cbor-diag"
+version = "0.1.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc245b6ecd09b23901a4fbad1ad975701fd5061ceaef6afa93a2d70605a64429"
+dependencies = [
+ "bs58",
+ "chrono",
+ "data-encoding",
+ "half",
+ "nom 7.1.3",
+ "num-bigint",
+ "num-rational",
+ "num-traits",
+ "separator",
+ "url",
+ "uuid",
+]
+
 [[package]]
 name = "cc"
 version = "1.4.0"
@@ -1888,9 +1968,9 @@ dependencies = [

 [[package]]
 name = "clap"
-version = "4.6.4"
+version = "4.6.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d91e0c145792ef73a6ad36d27c75ac09f1832222a3c209689d90f534685ee5b7"
+checksum = "301b56658598e48f3648647ac6fc887be7e7108eddfa4e9b63fcf3ec58c0cadf"
 dependencies = [
 "clap_builder",
 "clap_derive",
@@ -1898,9 +1978,9 @@ dependencies = [

 [[package]]
 name = "clap_builder"
-version = "4.6.2"
+version = "4.6.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f09628afdcc538b57f3c6341e9c8e9970f18e4a481690a64974d7023bd33548b"
+checksum = "94a65403d1a1bd28f7dc68eb8506e8874808ee5eecb59298de588e2e1407a078"
 dependencies = [
 "anstream",
 "anstyle",
@@ -3672,6 +3752,7 @@ dependencies = [
 "flate2",
 "futures",
 "hex",
+ "hotpath",
 "http 1.5.0",
 "http-body-util",
 "hyper",
@@ -4372,9 +4453,9 @@ dependencies = [

 [[package]]
 name = "google-cloud-auth"
-version = "1.14.0"
+version = "1.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a3494870d06f3cbbb3561ada6f234982549e3a2fb31e719ef258e6eadb9ae09a"
+checksum = "f54aab44c16b8463ae11b165a87c3d484780231f157bb1ed65843d591beb5abd"
 dependencies = [
 "async-trait",
 "aws-lc-rs",
@@ -4401,9 +4482,9 @@ dependencies = [

 [[package]]
 name = "google-cloud-gax"
-version = "1.12.0"
+version = "1.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3103a4a9013f1aed573ca56e19a9680b0211643a99ea85caf524b397d6be8be3"
+checksum = "b9a46dd0fd026bbc4a5d84e6ab0c941cee6e3b057976a0bb107fdb5238ce598f"
 dependencies = [
 "bytes",
 "futures",
@@ -4420,9 +4501,9 @@ dependencies = [

 [[package]]
 name = "google-cloud-gax-internal"
-version = "0.7.15"
+version = "0.7.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c0df265fba091ed7e00ecd0755009423310163f8b52820f007b6b4d97f4c6617"
+checksum = "fb04c54317ace06d489213f761797240b3046142a9b7ce6b9a82a9d134e193d1"
 dependencies = [
 "bytes",
 "futures",
@@ -4524,9 +4605,9 @@ dependencies = [

 [[package]]
 name = "google-cloud-storage"
-version = "1.16.0"
+version = "1.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc4b1d78c88db5c2530b12461e373a7d0d3a6caa3f6c1fc14e5d824cf2aeb307"
+checksum = "9227f65175fa91a6e41f246797917697efdadfe09dd8ea84ad8b737a71efbd28"
 dependencies = [
 "async-trait",
 "base64 0.22.1",
@@ -4577,9 +4658,9 @@ dependencies = [

 [[package]]
 name = "google-cloud-wkt"
-version = "1.6.0"
+version = "1.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "46df1fcc3ab69164af3f4199ed21f45b5dbc56d9f03211eb4fa20116d442364b"
+checksum = "7fccf98cfd5481a5f5a285181ab0c62123d7d47cd2bb7299448440649349e4e7"
 dependencies = [
 "base64 0.22.1",
 "bytes",
@@ -4916,19 +4997,31 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "66750a77f4f6b408a148be5102ef1f3ba7172def7ee92b1cfc75d9f7a3870453"
 dependencies = [
 "arc-swap",
+ "async-channel",
+ "async-trait",
 "cfg-if",
 "crossbeam-channel",
+ "flate2",
+ "futures-channel",
 "futures-util",
 "hdrhistogram",
 "hotpath-macros",
+ "hotpath-meta",
+ "http 1.5.0",
 "libc",
+ "object 0.36.7",
+ "parking_lot",
 "pin-project-lite",
 "prettytable-rs",
 "quanta",
 "regex",
+ "reqwest",
+ "reqwest-middleware",
+ "rustc-demangle",
 "serde",
 "serde_json",
 "tiny_http",
+ "tokio",
 ]

 [[package]]
@@ -4942,6 +5035,21 @@ dependencies = [
 "syn 2.0.119",
 ]

+[[package]]
+name = "hotpath-macros-meta"
+version = "0.22.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "21f2f70b29b6f42311acd2fb0b2f91a34d9a573c76fb8a7f51970670a1673a49"
+
+[[package]]
+name = "hotpath-meta"
+version = "0.22.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b771f77b2f409086bb40ff029f850ce99d17118d4e207df0f28cb32bd7568c7"
+dependencies = [
+ "hotpath-macros-meta",
+]
+
 [[package]]
 name = "htmlescape"
 version = "0.3.1"
@@ -5023,9 +5131,9 @@ checksum = "15cdd26707701c53297e2fa6afb323d55fbc1d0810c3aec078ae3ef0424c3c15"

 [[package]]
 name = "hybrid-array"
-version = "0.4.13"
+version = "0.4.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "818356c5132c1fede50f837ca96afbe78ff42413047f4abb886217845e1b6c8c"
+checksum = "707114b52a152fa7bdb290cd7cd5912d9467273b6d74e21b8d81aca1f8533f6b"
 dependencies = [
 "ctutils",
 "subtle",
@@ -5807,8 +5915,7 @@ checksum = "b6d2cec3eae94f9f509c767b45932f1ada8350c4bdb85af2fcab4a3c14807981"
 [[package]]
 name = "libmimalloc-sys"
 version = "0.1.49"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a45a52f43e1c16f667ccfe4dd8c85b7f7c204fd5e3bf46c5b0db9a5c3c0b8e9"
+source = "git+https://github.com/xonatius/mimalloc_rust.git?rev=1cdadea43e9c5a0f054b65be21200ce580e4eb13#1cdadea43e9c5a0f054b65be21200ce580e4eb13"
 dependencies = [
 "cc",
 "cty",
@@ -6217,8 +6324,7 @@ dependencies = [
 [[package]]
 name = "mimalloc"
 version = "0.1.52"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2d4139bb28d14ad1facf21d5eb8825051b326e172d216b39f6d31df53cc97862"
+source = "git+https://github.com/xonatius/mimalloc_rust.git?rev=1cdadea43e9c5a0f054b65be21200ce580e4eb13#1cdadea43e9c5a0f054b65be21200ce580e4eb13"
 dependencies = [
 "libmimalloc-sys",
 ]
@@ -6640,6 +6746,17 @@ dependencies = [
 "num-traits",
 ]

+[[package]]
+name = "num-rational"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f83d14da390562dca69fc84082e73e548e1ad308d24accdedd2720017cb37824"
+dependencies = [
+ "num-bigint",
+ "num-integer",
+ "num-traits",
+]
+
 [[package]]
 name = "num-traits"
 version = "0.2.19"
@@ -6704,7 +6821,7 @@ version = "5.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "51e219e79014df21a225b1860a479e2dcd7cbd9130f4defd4bd0e191ea31d67d"
 dependencies = [
- "base64 0.21.7",
+ "base64 0.22.1",
 "chrono",
 "getrandom 0.2.17",
 "http 1.5.0",
@@ -6783,6 +6900,15 @@ dependencies = [
 "objc2-core-foundation",
 ]

+[[package]]
+name = "object"
+version = "0.36.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62948e14d923ea95ea2c7c86c71013138b66525b86bdc08d2dcc262bdb497b87"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "object"
 version = "0.37.3"
@@ -7820,7 +7946,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "be769465445e8c1474e9c5dac2018218498557af32d9ed057325ec9a41ae81bf"
 dependencies = [
 "heck",
- "itertools 0.10.5",
+ "itertools 0.14.0",
 "log",
 "multimap",
 "once_cell",
@@ -7840,7 +7966,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "03da047801ff44bb6a4d407d4860c05fd70bb81714e6b2f3812603d5b145b042"
 dependencies = [
 "heck",
- "itertools 0.10.5",
+ "itertools 0.14.0",
 "log",
 "multimap",
 "petgraph 0.8.3",
@@ -7861,7 +7987,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8a56d757972c98b346a9b766e3f02746cde6dd1cd1d1d563472929fdd74bec4d"
 dependencies = [
 "anyhow",
- "itertools 0.10.5",
+ "itertools 0.14.0",
 "proc-macro2",
 "quote",
 "syn 2.0.119",
@@ -7874,7 +8000,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b570b25f7617e43d59005d0990ccb79e950a423952cea19671b7a876da390adf"
 dependencies = [
 "anyhow",
- "itertools 0.10.5",
+ "itertools 0.14.0",
 "proc-macro2",
 "quote",
 "syn 2.0.119",
@@ -8514,6 +8640,21 @@ dependencies = [
 "web-sys",
 ]

+[[package]]
+name = "reqwest-middleware"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "07bc3f1384cffa4f274dad2d4ddd73aed32fed8f786d96c6be8aa4e5fd3c3b58"
+dependencies = [
+ "anyhow",
+ "async-trait",
+ "http 1.5.0",
+ "reqwest",
+ "serde",
+ "thiserror 2.0.19",
+ "tower-service",
+]
+
 [[package]]
 name = "resolv-conf"
 version = "0.7.6"
@@ -8579,6 +8720,15 @@ dependencies = [
 "serde",
 ]

+[[package]]
+name = "roxmltree"
+version = "0.14.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "921904a62e410e37e215c40381b7117f830d9d89ba60ab5236170541dd25646b"
+dependencies = [
+ "xmlparser",
+]
+
 [[package]]
 name = "rsa"
 version = "0.9.10"
@@ -8672,9 +8822,9 @@ dependencies = [

 [[package]]
 name = "russh"
-version = "0.62.4"
+version = "0.62.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b8b67b5a0d8068c89dcbe9d95df986af7a851d1f3c604525274c37468e60464f"
+checksum = "da7c230e0ed9cbeb92fbad6c8848985d6df2a1464c0dc247a021abd666e9005e"
 dependencies = [
 "aes 0.9.2",
 "aws-lc-rs",
@@ -8975,6 +9125,7 @@ dependencies = [
 "url",
 "urlencoding",
 "uuid",
+ "zeroize",
 "zip",
 "zstd",
 ]
@@ -8988,6 +9139,7 @@ dependencies = [
 "const-str",
 "futures",
 "hashbrown 0.17.1",
+ "hotpath",
 "metrics",
 "rustfs-config",
 "rustfs-s3-types",
@@ -9008,6 +9160,7 @@ dependencies = [
 "base64-simd",
 "bytes",
 "crc-fast",
+ "hotpath",
 "http 1.5.0",
 "md-5 0.11.0",
 "pretty_assertions",
@@ -9021,6 +9174,7 @@ name = "rustfs-common"
 version = "1.0.0-beta.12"
 dependencies = [
 "chrono",
+ "hotpath",
 "metrics",
 "rmp-serde",
 "s3s",
@@ -9035,6 +9189,7 @@ dependencies = [
 name = "rustfs-concurrency"
 version = "1.0.0-beta.12"
 dependencies = [
+ "hotpath",
 "insta",
 "rustfs-io-core",
 "serde",
@@ -9048,6 +9203,7 @@ name = "rustfs-config"
 version = "1.0.0-beta.12"
 dependencies = [
 "const-str",
+ "hotpath",
 "serde",
 "serde_json",
 ]
@@ -9058,6 +9214,7 @@ version = "1.0.0-beta.12"
 dependencies = [
 "base64-simd",
 "hmac 0.13.0",
+ "hotpath",
 "rand 0.10.2",
 "serde",
 "serde_json",
@@ -9073,6 +9230,7 @@ dependencies = [
 "argon2",
 "base64-simd",
 "chacha20poly1305",
+ "hotpath",
 "jsonwebtoken 11.0.0",
 "pbkdf2 0.13.0",
 "rand 0.10.2",
@@ -9090,6 +9248,7 @@ name = "rustfs-data-usage"
 version = "1.0.0-beta.12"
 dependencies = [
 "async-trait",
+ "hotpath",
 "rmp-serde",
 "rustfs-filemeta",
 "serde",
@@ -9099,7 +9258,6 @@ dependencies = [
 name = "rustfs-ecstore"
 version = "1.0.0-beta.12"
 dependencies = [
- "aes-gcm",
 "arc-swap",
 "async-channel",
 "async-recursion",
@@ -9115,7 +9273,6 @@ dependencies = [
 "byteorder",
 "bytes",
 "bytesize",
- "chacha20poly1305",
 "chrono",
 "criterion",
 "enumset",
@@ -9128,6 +9285,7 @@ dependencies = [
 "google-cloud-storage",
 "hex-simd",
 "hmac 0.13.0",
+ "hostname",
 "hotpath",
 "http 1.5.0",
 "http-body 1.1.0",
@@ -9168,7 +9326,6 @@ dependencies = [
 "rustfs-erasure-codec",
 "rustfs-filemeta",
 "rustfs-io-metrics",
- "rustfs-kms",
 "rustfs-lifecycle",
 "rustfs-lock",
 "rustfs-madmin",
@@ -9237,6 +9394,7 @@ dependencies = [
 name = "rustfs-extension-schema"
 version = "1.0.0-beta.12"
 dependencies = [
+ "hotpath",
 "serde",
 "serde_json",
 "thiserror 2.0.19",
@@ -9275,6 +9433,7 @@ dependencies = [
 "async-trait",
 "base64 0.23.0",
 "futures",
+ "hotpath",
 "http 1.5.0",
 "metrics",
 "rustfs-common",
@@ -9306,6 +9465,7 @@ dependencies = [
 "async-trait",
 "base64-simd",
 "futures",
+ "hotpath",
 "http 1.5.0",
 "jsonwebtoken 11.0.0",
 "moka",
@@ -9340,6 +9500,7 @@ name = "rustfs-io-core"
 version = "1.0.0-beta.12"
 dependencies = [
 "bytes",
+ "hotpath",
 "memmap2",
 "rustfs-io-metrics",
 "thiserror 2.0.19",
@@ -9352,10 +9513,13 @@ name = "rustfs-io-metrics"
 version = "1.0.0-beta.12"
 dependencies = [
 "criterion",
+ "hotpath",
 "metrics",
 "metrics-util",
 "num_cpus",
+ "rustfs-common",
 "rustfs-s3-ops",
+ "rustfs-utils",
 "sysinfo",
 "thiserror 2.0.19",
 "tokio",
@@ -9416,6 +9580,7 @@ version = "1.0.0-beta.12"
 dependencies = [
 "bytes",
 "futures",
+ "hotpath",
 "http 1.5.0",
 "http-body 1.1.0",
 "http-body-util",
@@ -9441,20 +9606,32 @@ name = "rustfs-kms"
 version = "1.0.0-beta.12"
 dependencies = [
 "aes-gcm",
+ "anyhow",
 "arc-swap",
 "argon2",
 "async-trait",
+ "aws-config",
+ "aws-sdk-kms",
+ "aws-smithy-http-client",
+ "aws-smithy-runtime-api",
+ "aws-smithy-types",
 "base64 0.23.0",
 "chacha20poly1305",
 "hex",
+ "hotpath",
+ "http 1.5.0",
 "insta",
 "jiff",
 "md-5 0.11.0",
+ "metrics",
+ "metrics-util",
 "moka",
 "rand 0.10.2",
 "reqwest",
+ "rustfs-s3-types",
 "rustfs-security-governance",
 "rustfs-utils",
+ "rustify",
 "serde",
 "serde_json",
 "sha2 0.11.0",
@@ -9463,6 +9640,7 @@ dependencies = [
 "tempfile",
 "thiserror 2.0.19",
 "tokio",
+ "tokio-util",
 "tracing",
 "url",
 "uuid",
@@ -9475,6 +9653,7 @@ name = "rustfs-lifecycle"
 version = "1.0.0-beta.12"
 dependencies = [
 "async-trait",
+ "hotpath",
 "metrics",
 "metrics-util",
 "proptest",
@@ -9499,6 +9678,7 @@ dependencies = [
 "async-trait",
 "crossbeam-queue",
 "futures",
+ "hotpath",
 "parking_lot",
 "rand 0.10.2",
 "rustfs-io-metrics",
@@ -9520,6 +9700,7 @@ version = "1.0.0-beta.12"
 dependencies = [
 "chrono",
 "flate2",
+ "hotpath",
 "regex",
 "serde",
 "serde_json",
@@ -9537,6 +9718,7 @@ name = "rustfs-madmin"
 version = "1.0.0-beta.12"
 dependencies = [
 "chrono",
+ "hotpath",
 "humantime",
 "hyper",
 "rmp-serde",
@@ -9557,6 +9739,7 @@ dependencies = [
 "criterion",
 "form_urlencoded",
 "hashbrown 0.17.1",
+ "hotpath",
 "metrics",
 "percent-encoding",
 "quick-xml",
@@ -9586,6 +9769,7 @@ version = "1.0.0-beta.12"
 dependencies = [
 "criterion",
 "futures",
+ "hotpath",
 "rustfs-config",
 "rustfs-io-metrics",
 "rustfs-utils",
@@ -9604,6 +9788,7 @@ version = "1.0.0-beta.12"
 dependencies = [
 "bytes",
 "criterion",
+ "hotpath",
 "metrics",
 "metrics-util",
 "moka",
@@ -9626,8 +9811,10 @@ dependencies = [
 "flate2",
 "futures-util",
 "glob",
+ "hotpath",
 "jiff",
 "libc",
+ "log",
 "metrics",
 "num_cpus",
 "nvml-wrapper",
@@ -9663,6 +9850,7 @@ dependencies = [
 "tracing-error",
 "tracing-opentelemetry",
 "tracing-subscriber",
+ "url",
 "zstd",
 ]

@@ -9674,6 +9862,7 @@ dependencies = [
 "base64-simd",
 "chrono",
 "futures",
+ "hotpath",
 "ipnetwork",
 "jsonwebtoken 11.0.0",
 "moka",
@@ -9693,6 +9882,7 @@ dependencies = [
 "time",
 "tokio",
 "tracing",
+ "tracing-subscriber",
 ]

 [[package]]
@@ -9710,6 +9900,7 @@ dependencies = [
 "futures-util",
 "hex",
 "hmac 0.13.0",
+ "hotpath",
 "http 1.5.0",
 "http-body-util",
 "hyper",
@@ -9762,6 +9953,7 @@ name = "rustfs-protos"
 version = "1.0.0-beta.12"
 dependencies = [
 "flatbuffers",
+ "hotpath",
 "prost 0.14.4",
 "rmp-serde",
 "rustfs-common",
@@ -9786,6 +9978,7 @@ version = "1.0.0-beta.12"
 dependencies = [
 "byteorder",
 "bytes",
+ "hotpath",
 "regex",
 "rmp",
 "rmp-serde",
@@ -9844,6 +10037,7 @@ dependencies = [
 "chacha20poly1305",
 "hex",
 "hmac 0.13.0",
+ "hotpath",
 "minlz",
 "pin-project-lite",
 "rand 0.10.2",
@@ -9861,6 +10055,7 @@ dependencies = [
 name = "rustfs-s3-ops"
 version = "1.0.0-beta.12"
 dependencies = [
+ "hotpath",
 "rustfs-s3-types",
 ]

@@ -9868,6 +10063,7 @@ dependencies = [
 name = "rustfs-s3-types"
 version = "1.0.0-beta.12"
 dependencies = [
+ "hotpath",
 "serde",
 "serde_json",
 ]
@@ -9882,6 +10078,7 @@ dependencies = [
 "datafusion",
 "futures",
 "futures-core",
+ "hotpath",
 "http 1.5.0",
 "metrics",
 "parking_lot",
@@ -9910,6 +10107,7 @@ dependencies = [
 "datafusion",
 "derive_builder",
 "futures",
+ "hotpath",
 "parking_lot",
 "rustfs-s3select-api",
 "s3s",
@@ -9927,6 +10125,7 @@ dependencies = [
 "futures",
 "hex-simd",
 "hmac 0.13.0",
+ "hotpath",
 "http 1.5.0",
 "metrics",
 "rand 0.10.2",
@@ -9937,6 +10136,7 @@ dependencies = [
 "rustfs-data-usage",
 "rustfs-ecstore",
 "rustfs-filemeta",
+ "rustfs-lock",
 "rustfs-storage-api",
 "rustfs-utils",
 "s3s",
@@ -9959,6 +10159,7 @@ dependencies = [
 name = "rustfs-security-governance"
 version = "1.0.0-beta.12"
 dependencies = [
+ "hotpath",
 "thiserror 2.0.19",
 ]

@@ -9968,6 +10169,7 @@ version = "1.0.0-beta.12"
 dependencies = [
 "base64-simd",
 "bytes",
+ "hotpath",
 "http 1.5.0",
 "hyper",
 "rustfs-utils",
@@ -9984,6 +10186,7 @@ name = "rustfs-storage-api"
 version = "1.0.0-beta.12"
 dependencies = [
 "async-trait",
+ "hotpath",
 "insta",
 "rustfs-filemeta",
 "serde",
@@ -10005,6 +10208,7 @@ dependencies = [
 "deadpool-postgres",
 "futures-util",
 "hashbrown 0.17.1",
+ "hotpath",
 "hyper",
 "hyper-rustls",
 "lapin",
@@ -10050,6 +10254,7 @@ dependencies = [
 name = "rustfs-test-utils"
 version = "1.0.0-beta.12"
 dependencies = [
+ "hotpath",
 "rustfs-data-usage",
 "rustfs-ecstore",
 "rustfs-storage-api",
@@ -10066,6 +10271,7 @@ name = "rustfs-tls-runtime"
 version = "1.0.0-beta.12"
 dependencies = [
 "arc-swap",
+ "hotpath",
 "metrics",
 "rcgen",
 "rustfs-common",
@@ -10087,6 +10293,7 @@ version = "1.0.0-beta.12"
 dependencies = [
 "async-trait",
 "axum",
+ "hotpath",
 "http 1.5.0",
 "ipnetwork",
 "metrics",
@@ -10133,6 +10340,7 @@ dependencies = [
 "hex-simd",
 "highway",
 "hmac 0.13.0",
+ "hotpath",
 "http 1.5.0",
 "hyper",
 "local-ip-address",
@@ -10165,6 +10373,7 @@ dependencies = [
 "astral-tokio-tar",
 "async-compression",
 "criterion",
+ "hotpath",
 "tempfile",
 "thiserror 2.0.19",
 "tokio",
@@ -10561,6 +10770,12 @@ dependencies = [
 "serde_core",
 ]

+[[package]]
+name = "separator"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f97841a747eef040fcd2e7b3b9a220a7205926e60488e673d9e4926d27772ce5"
+
 [[package]]
 name = "seq-macro"
 version = "0.3.6"
@@ -173,7 +173,7 @@ tower-http = { version = "0.7.0" }
 # Serialization and Data Formats
 apache-avro = "0.21.0"
 bytes = { version = "1.12.1" }
-bytesize = "2.4.2"
+bytesize = "2.6.0"
 byteorder = "1.5.0"
 flatbuffers = "25.12.19"
 form_urlencoded = "1.2.2"
@@ -227,6 +227,7 @@ atoi = "3.1.0"
 atomic_enum = "0.3.0"
 aws-config = { version = "1.10.1" }
 aws-credential-types = { version = "1.3.0" }
+aws-sdk-kms = { default-features = false, version = "1.114.0" }
 aws-sdk-s3 = { default-features = false, version = "1.140.0" }
 aws-sdk-sts = { default-features = false, version = "1.110.0" }
 aws-smithy-http-client = { default-features = false, version = "1.2.0" }
@@ -235,7 +236,7 @@ aws-smithy-types = { version = "1.6.1" }
 base64 = "0.23.0"
 base64-simd = "0.8.0"
 brotli = "8.0.4"
-clap = { version = "4.6.4" }
+clap = { version = "4.6.5" }
 const-str = { version = "1.1.0" }
 convert_case = "0.11.0"
 criterion = { version = "0.8" }
@@ -250,12 +251,13 @@ enumset = "1.1.14"
 faster-hex = "0.10.0"
 flate2 = "1.1.9"
 glob = "0.3.4"
-google-cloud-storage = "1.16.0"
-google-cloud-auth = "1.14.0"
+google-cloud-storage = "1.17.0"
+google-cloud-auth = "1.15.0"
 hashbrown = { version = "0.17.1" }
 hex = "0.4.3"
 hex-simd = "0.8.0"
 highway = { version = "1.3.0" }
+hostname = "0.4.2"
 ipnetwork = { version = "0.21.1" }
 lazy_static = "1.5.0"
 libc = "0.2.189"
@@ -284,6 +286,7 @@ reed-solomon-simd = "3.1.0"
 regex = { version = "1.13.1" }
 rumqttc = { package = "rumqttc-next", version = "0.33.3" }
 redis = { version = "1.5.0" }
+rustify = { version = "0.7", default-features = false }
 rustix = { version = "1.1.4" }
 rust-embed = { version = "8.12.0" }
 rustc-hash = { version = "2.1.3" }
@@ -338,15 +341,16 @@ libunftp = { version = "0.23.0" }
 unftp-core = "0.1.0"
 suppaftp = { version = "10.0.1" }
 rcgen = { version = "0.14.8", default-features = false, features = ["aws_lc_rs", "crypto", "pem"] }
-russh = { version = "0.62.4" }
+russh = { version = "0.62.5" }
 russh-sftp = "2.3.0"

 # WebDAV
 dav-server = "0.11.0"

 # Performance Analysis and Memory Profiling
-mimalloc = "0.1.52"
-hotpath = "0.22.0"
+mimalloc = { version = "0.1.52", git = "https://github.com/xonatius/mimalloc_rust.git", rev = "1cdadea43e9c5a0f054b65be21200ce580e4eb13" }
+libmimalloc-sys = { version = "0.1.49", git = "https://github.com/xonatius/mimalloc_rust.git", rev = "1cdadea43e9c5a0f054b65be21200ce580e4eb13", features = ["extended"] }
+hotpath = { version = "0.22.0", default-features = false }
 # Snapshot testing for output format regression detection
 insta = { version = "1.48" }

@@ -25,7 +25,33 @@ documentation = "https://docs.rs/rustfs-audit/latest/rustfs_audit/"
 keywords = ["audit", "target", "management", "fan-out", "RustFS"]
 categories = ["web-programming", "development-tools", "asynchronous", "api-bindings"]

+[features]
+default = []
+hotpath = [
+    "hotpath/hotpath",
+    "hotpath/tokio",
+    "hotpath/futures",
+    "rustfs-config/hotpath",
+    "rustfs-s3-types/hotpath",
+    "rustfs-targets/hotpath",
+]
+hotpath-alloc = [
+    "hotpath",
+    "hotpath/hotpath-alloc",
+    "rustfs-config/hotpath-alloc",
+    "rustfs-s3-types/hotpath-alloc",
+    "rustfs-targets/hotpath-alloc",
+]
+hotpath-cpu = [
+    "hotpath",
+    "hotpath/hotpath-cpu",
+    "rustfs-config/hotpath-cpu",
+    "rustfs-s3-types/hotpath-cpu",
+    "rustfs-targets/hotpath-cpu",
+]
+
 [dependencies]
+hotpath.workspace = true
 rustfs-targets = { workspace = true }
 rustfs-config = { workspace = true, features = ["audit", "server-config-model"] }
 rustfs-s3-types = { workspace = true }
@@ -28,7 +28,14 @@ documentation = "https://docs.rs/rustfs-checksums/latest/rustfs_checksum/"
 [lints]
 workspace = true

+[features]
+default = []
+hotpath = ["hotpath/hotpath"]
+hotpath-alloc = ["hotpath", "hotpath/hotpath-alloc"]
+hotpath-cpu = ["hotpath", "hotpath/hotpath-cpu"]
+
 [dependencies]
+hotpath.workspace = true
 bytes = { workspace = true, features = ["serde"] }
 crc-fast = { workspace = true }
 http = { workspace = true }
@@ -27,7 +27,14 @@ categories = ["web-programming", "development-tools", "data-structures"]
 [lints]
 workspace = true

+[features]
+default = []
+hotpath = ["hotpath/hotpath", "hotpath/tokio"]
+hotpath-alloc = ["hotpath", "hotpath/hotpath-alloc"]
+hotpath-cpu = ["hotpath", "hotpath/hotpath-cpu"]
+
 [dependencies]
+hotpath.workspace = true
 tokio = { workspace = true, features = ["fs", "rt-multi-thread"] }
 tonic = { workspace = true, features = ["gzip", "deflate"] }
 uuid = { workspace = true, features = ["v4", "fast-rng", "macro-diagnostics"] }
@@ -13,7 +13,14 @@ categories = ["concurrency", "filesystem"]
 [lints]
 workspace = true

+[features]
+default = []
+hotpath = ["hotpath/hotpath", "hotpath/tokio", "rustfs-io-core/hotpath"]
+hotpath-alloc = ["hotpath", "hotpath/hotpath-alloc", "rustfs-io-core/hotpath-alloc"]
+hotpath-cpu = ["hotpath", "hotpath/hotpath-cpu", "rustfs-io-core/hotpath-cpu"]
+
 [dependencies]
+hotpath.workspace = true
 # Internal crates
 rustfs-io-core = { workspace = true }
 serde = { workspace = true, features = ["derive"] }
@@ -25,6 +25,7 @@ keywords = ["configuration", "settings", "management", "rustfs", "Minio"]
 categories = ["web-programming", "development-tools", "config"]

 [dependencies]
+hotpath.workspace = true
 const-str = { workspace = true, optional = true, features = ["std", "proc"] }
 serde = { workspace = true, optional = true, features = ["derive"] }
 serde_json = { workspace = true, optional = true, features = ["raw_value"] }
@@ -34,6 +35,9 @@ workspace = true

 [features]
 default = ["constants"]
+hotpath = ["hotpath/hotpath"]
+hotpath-alloc = ["hotpath", "hotpath/hotpath-alloc"]
+hotpath-cpu = ["hotpath", "hotpath/hotpath-cpu"]
 audit = ["dep:const-str", "constants"]
 constants = ["dep:const-str"]
 notify = ["dep:const-str", "constants"]
@@ -66,6 +66,10 @@ Current guidance:

 - `RUSTFS_BROWSER_REDIRECT_URL` sets the externally reachable browser origin used for OIDC callback, console success redirect, and logout fallback URLs. Configure it to the public scheme and authority without a path, for example `https://console.example.com`. In load-balancer deployments, keep OIDC authorize and callback requests on the same backend node because the in-flight OIDC `state` is local to the RustFS node.

+## Distributed endpoint locality
+
+- `RUSTFS_LOCAL_ENDPOINT_HOST` identifies this server's host in a distributed `RUSTFS_VOLUMES` topology without resolving every peer during startup. Set it to exactly one host, without a scheme, port, or path. It is accepted only for orchestrated URL topologies and must match at least one endpoint on the RustFS server port; invalid or unmatched values fail startup. Leave it unset to retain DNS-based locality discovery.
+
 ## Scanner environment aliases

 - `RUSTFS_SCANNER_SPEED` (canonical, also accepts `MINIO_SCANNER_SPEED`)
@@ -131,6 +131,10 @@ pub const ENV_RUSTFS_ADDRESS: &str = "RUSTFS_ADDRESS";
 /// Environment variable for server volumes.
 pub const ENV_RUSTFS_VOLUMES: &str = "RUSTFS_VOLUMES";

+/// Environment variable identifying this server's host in distributed endpoint
+/// lists without relying on DNS locality discovery.
+pub const ENV_LOCAL_ENDPOINT_HOST: &str = "RUSTFS_LOCAL_ENDPOINT_HOST";
+
 /// Environment variable to explicitly bypass local physical disk independence checks.
 pub const ENV_UNSAFE_BYPASS_DISK_CHECK: &str = "RUSTFS_UNSAFE_BYPASS_DISK_CHECK";

@@ -226,6 +230,19 @@ pub const ENV_RUSTFS_KMS_ENABLE: &str = "RUSTFS_KMS_ENABLE";
 /// Default value: false
 pub const DEFAULT_KMS_ENABLE: bool = false;

+/// Environment variable enabling per-key KMS authorization on the SSE-KMS data path.
+///
+/// When enabled, an SSE-KMS write additionally requires `kms:GenerateDataKey` and an
+/// SSE-KMS read additionally requires `kms:Decrypt` on the resolved key, evaluated as
+/// the requesting identity. SSE-S3 and SSE-C are unaffected.
+pub const ENV_RUSTFS_KMS_ENFORCE_SSE_KEY_POLICY: &str = "RUSTFS_KMS_ENFORCE_SSE_KEY_POLICY";
+
+/// Default per-key KMS authorization mode for the SSE-KMS data path.
+///
+/// Off for now so deployments whose identity policies only grant s3 actions keep
+/// working; the default flips to on in a later release.
+pub const DEFAULT_KMS_ENFORCE_SSE_KEY_POLICY: bool = false;
+
 /// Environment variable for server KMS backend.
 pub const ENV_RUSTFS_KMS_BACKEND: &str = "RUSTFS_KMS_BACKEND";

@@ -24,7 +24,14 @@ description = "Credentials management utilities for RustFS, enabling secure hand
 keywords = ["rustfs", "Minio", "credentials", "authentication", "authorization"]
 categories = ["web-programming", "development-tools", "data-structures", "security"]

+[features]
+default = []
+hotpath = ["hotpath/hotpath"]
+hotpath-alloc = ["hotpath", "hotpath/hotpath-alloc"]
+hotpath-cpu = ["hotpath", "hotpath/hotpath-cpu"]
+
 [dependencies]
+hotpath.workspace = true
 base64-simd = { workspace = true }
 hmac = { workspace = true }
 rand = { workspace = true, features = ["serde"] }
@@ -29,6 +29,7 @@ documentation = "https://docs.rs/rustfs-crypto/latest/rustfs_crypto/"
 workspace = true

 [dependencies]
+hotpath.workspace = true
 aes-gcm = { workspace = true, optional = true, features = ["rand_core"] }
 argon2 = { workspace = true, optional = true }
 chacha20poly1305 = { workspace = true, optional = true }
@@ -49,6 +50,9 @@ time = { workspace = true, features = ["parsing", "formatting", "macros", "serde

 [features]
 default = ["crypto", "fips"]
+hotpath = ["hotpath/hotpath"]
+hotpath-alloc = ["hotpath", "hotpath/hotpath-alloc"]
+hotpath-cpu = ["hotpath", "hotpath/hotpath-cpu"]
 fips = []
 crypto = [
    "dep:aes-gcm",
@@ -27,7 +27,14 @@ categories = ["data-structures", "filesystem"]
 [lints]
 workspace = true

+[features]
+default = []
+hotpath = ["hotpath/hotpath", "rustfs-filemeta/hotpath"]
+hotpath-alloc = ["hotpath", "hotpath/hotpath-alloc", "rustfs-filemeta/hotpath-alloc"]
+hotpath-cpu = ["hotpath", "hotpath/hotpath-cpu", "rustfs-filemeta/hotpath-cpu"]
+
 [dependencies]
+hotpath.workspace = true
 serde = { workspace = true, features = ["derive"] }
 rmp-serde = { workspace = true }
 async-trait = { workspace = true }
@@ -25,10 +25,58 @@ workspace = true

 [features]
 default = []
+hotpath = [
+    "hotpath/hotpath",
+    "hotpath/tokio",
+    "hotpath/futures",
+    "hotpath/reqwest-0-13",
+    "rustfs-config/hotpath",
+    "rustfs-credentials/hotpath",
+    "rustfs-data-usage/hotpath",
+    "rustfs-ecstore/hotpath",
+    "rustfs-filemeta/hotpath",
+    "rustfs-lock/hotpath",
+    "rustfs-madmin/hotpath",
+    "rustfs-protos/hotpath",
+    "rustfs-rio/hotpath",
+    "rustfs-signer/hotpath",
+    "rustfs-utils/hotpath",
+]
+hotpath-alloc = [
+    "hotpath",
+    "hotpath/hotpath-alloc",
+    "rustfs-config/hotpath-alloc",
+    "rustfs-credentials/hotpath-alloc",
+    "rustfs-data-usage/hotpath-alloc",
+    "rustfs-ecstore/hotpath-alloc",
+    "rustfs-filemeta/hotpath-alloc",
+    "rustfs-lock/hotpath-alloc",
+    "rustfs-madmin/hotpath-alloc",
+    "rustfs-protos/hotpath-alloc",
+    "rustfs-rio/hotpath-alloc",
+    "rustfs-signer/hotpath-alloc",
+    "rustfs-utils/hotpath-alloc",
+]
+hotpath-cpu = [
+    "hotpath",
+    "hotpath/hotpath-cpu",
+    "rustfs-config/hotpath-cpu",
+    "rustfs-credentials/hotpath-cpu",
+    "rustfs-data-usage/hotpath-cpu",
+    "rustfs-ecstore/hotpath-cpu",
+    "rustfs-filemeta/hotpath-cpu",
+    "rustfs-lock/hotpath-cpu",
+    "rustfs-madmin/hotpath-cpu",
+    "rustfs-protos/hotpath-cpu",
+    "rustfs-rio/hotpath-cpu",
+    "rustfs-signer/hotpath-cpu",
+    "rustfs-utils/hotpath-cpu",
+]
 ftps = []
 sftp = []

 [dependencies]
+hotpath.workspace = true
 rustfs-config = { workspace = true, features = ["constants"] }
 rustfs-credentials.workspace = true
 rustfs-ecstore.workspace = true
@@ -26,75 +26,16 @@
 //! Later batches tracked on backlog#1154: config get/set, info, pools status,
 //! group lifecycle, import/export IAM.

-use crate::common::{RustFSTestEnvironment, init_logging, local_http_client};
+use crate::common::{RustFSTestEnvironment, admin_ok, admin_request, init_logging};
 use aws_sdk_s3::config::{Credentials, Region};
 use aws_sdk_s3::primitives::ByteStream;
 use aws_sdk_s3::{Client, Config};
-use http::header::{CONTENT_TYPE, HOST};
 use reqwest::StatusCode;
-use rustfs_signer::constants::UNSIGNED_PAYLOAD;
-use rustfs_signer::sign_v4;
-use s3s::Body;
 use serial_test::serial;
 use std::error::Error;
 use tokio::time::{Duration, sleep};

 type TestResult = Result<(), Box<dyn Error + Send + Sync>>;
-type BoxError = Box<dyn Error + Send + Sync>;
-
-/// Signs and sends an admin HTTP request with the given credential, returning
-/// status and body. Native `/rustfs/admin/v3` requests and responses are plain
-/// JSON (the MinIO-compat encryption applies only to `/minio/admin/v3` paths).
-async fn admin_request(
-    base_url: &str,
-    method: http::Method,
-    path_and_query: &str,
-    body: Option<String>,
-    access_key: &str,
-    secret_key: &str,
-) -> Result<(StatusCode, String), BoxError> {
-    let url = format!("{base_url}{path_and_query}");
-    let uri = url.parse::<http::Uri>()?;
-    let authority = uri.authority().ok_or("admin URL missing authority")?.to_string();
-    let mut builder = http::Request::builder()
-        .method(method.clone())
-        .uri(uri)
-        .header(HOST, authority)
-        .header("x-amz-content-sha256", UNSIGNED_PAYLOAD);
-    if body.is_some() {
-        builder = builder.header(CONTENT_TYPE, "application/json");
-    }
-
-    let content_len = body.as_ref().map(|b| b.len() as i64).unwrap_or_default();
-    let signed = sign_v4(builder.body(Body::empty())?, content_len, access_key, secret_key, "", "us-east-1");
-
-    let reqwest_method = reqwest::Method::from_bytes(method.as_str().as_bytes())?;
-    let mut request = local_http_client().request(reqwest_method, &url);
-    for (name, value) in signed.headers() {
-        request = request.header(name, value);
-    }
-    if let Some(body) = body {
-        request = request.body(body);
-    }
-    let response = request.send().await?;
-    let status = response.status();
-    let text = response.text().await.unwrap_or_default();
-    Ok((status, text))
-}
-
-/// Root-credential admin request that must succeed; returns the response body.
-async fn admin_ok(
-    env: &RustFSTestEnvironment,
-    method: http::Method,
-    path_and_query: &str,
-    body: Option<String>,
-) -> Result<String, BoxError> {
-    let (status, text) = admin_request(&env.url, method.clone(), path_and_query, body, &env.access_key, &env.secret_key).await?;
-    if !status.is_success() {
-        return Err(format!("{method} {path_and_query} failed: {status} {text}").into());
-    }
-    Ok(text)
-}

 fn build_s3_client(url: &str, access_key: &str, secret_key: &str) -> Client {
    let config = Config::builder()
@@ -24,7 +24,12 @@
 use aws_sdk_s3::config::{Credentials, Region};
 use aws_sdk_s3::{Client, Config};
 use aws_smithy_http_client::Builder as SmithyHttpClientBuilder;
+use http::header::{CONTENT_TYPE, HOST};
 use reqwest::Client as HttpClient;
+use reqwest::StatusCode;
+use rustfs_signer::constants::UNSIGNED_PAYLOAD;
+use rustfs_signer::sign_v4;
+use s3s::Body;
 use std::ffi::OsStr;
 use std::fs as stdfs;
 use std::path::{Path, PathBuf};
@@ -75,6 +80,58 @@ pub fn local_http_client() -> HttpClient {
        .expect("failed to build local reqwest client")
 }

+/// Signs and sends an admin HTTP request with the given credentials.
+pub(crate) async fn admin_request(
+    base_url: &str,
+    method: http::Method,
+    path_and_query: &str,
+    body: Option<String>,
+    access_key: &str,
+    secret_key: &str,
+) -> Result<(StatusCode, String), Box<dyn std::error::Error + Send + Sync>> {
+    let url = format!("{base_url}{path_and_query}");
+    let uri = url.parse::<http::Uri>()?;
+    let authority = uri.authority().ok_or("admin URL missing authority")?.to_string();
+    let mut request = http::Request::builder()
+        .method(method.clone())
+        .uri(uri)
+        .header(HOST, authority)
+        .header("x-amz-content-sha256", UNSIGNED_PAYLOAD);
+    if body.is_some() {
+        request = request.header(CONTENT_TYPE, "application/json");
+    }
+
+    let content_length = i64::try_from(body.as_ref().map_or(0, String::len)).map_err(|_| "admin request body is too large")?;
+    let signed = sign_v4(request.body(Body::empty())?, content_length, access_key, secret_key, "", "us-east-1");
+
+    let mut request = local_http_client().request(method, &url);
+    for (name, value) in signed.headers() {
+        request = request.header(name, value);
+    }
+    if let Some(body) = body {
+        request = request.body(body);
+    }
+    let response = request.send().await?;
+    let status = response.status();
+    let body = response.text().await?;
+    Ok((status, body))
+}
+
+/// Sends a root-credential admin request and returns its successful response body.
+pub(crate) async fn admin_ok(
+    env: &RustFSTestEnvironment,
+    method: http::Method,
+    path_and_query: &str,
+    body: Option<String>,
+) -> Result<String, Box<dyn std::error::Error + Send + Sync>> {
+    let (status, response_body) =
+        admin_request(&env.url, method.clone(), path_and_query, body, &env.access_key, &env.secret_key).await?;
+    if !status.is_success() {
+        return Err(format!("{method} {path_and_query} failed: {status} {response_body}").into());
+    }
+    Ok(response_body)
+}
+
 /// Resolve the RustFS binary relative to the workspace.
 pub fn rustfs_binary_path() -> PathBuf {
    rustfs_binary_path_with_features(requested_rustfs_build_features().as_deref())
@@ -117,9 +117,14 @@ mod tests {
            .key("assets/explicit-copy.js")
            .copy_source(format!("{bucket}/{key}"))
            .metadata_directive(MetadataDirective::Copy)
+            .customize()
+            .mutate_request(|request| {
+                request.headers_mut().insert("content-type", "application/octet-stream");
+                request.headers_mut().insert("x-amz-meta-request-only", "ignored");
+            })
            .send()
            .await
-            .expect("explicit COPY directive failed");
+            .expect("explicit COPY directive with request metadata failed");
        let explicit_copy_head = client
            .head_object()
            .bucket(bucket)
@@ -128,6 +133,18 @@ mod tests {
            .await
            .expect("HEAD failed after explicit COPY");
        assert_eq!(explicit_copy_head.cache_control(), Some("max-age=60"));
+        assert_eq!(explicit_copy_head.content_type(), Some("text/javascript; charset=utf-8"));
+        assert_eq!(
+            explicit_copy_head.metadata().and_then(|metadata| metadata.get("mtime")),
+            Some(&"1777992333".to_string())
+        );
+        assert_eq!(
+            explicit_copy_head
+                .metadata()
+                .and_then(|metadata| metadata.get("request-only")),
+            None,
+            "COPY must ignore request metadata"
+        );
        assert_eq!(
            explicit_copy_head.website_redirect_location(),
            None,
@@ -571,20 +588,6 @@ mod tests {
            Some("InvalidArgument")
        );

-        let ignored_replacement = client
-            .copy_object()
-            .bucket(bucket)
-            .key(key)
-            .copy_source(format!("{bucket}/{key}"))
-            .content_type("application/ignored")
-            .send()
-            .await
-            .expect_err("Replacement fields without REPLACE should be rejected");
-        assert_eq!(
-            ignored_replacement.as_service_error().and_then(|error| error.code()),
-            Some("InvalidRequest")
-        );
-
        let unchanged = client
            .get_object()
            .bucket(bucket)
@@ -56,6 +56,21 @@ mod tests {
        );
    }

+    async fn assert_current_list_hides_delete_marker(client: &Client, bucket: &str, key: &str) {
+        let listed = client
+            .list_objects_v2()
+            .bucket(bucket)
+            .prefix(key)
+            .send()
+            .await
+            .expect("list current objects after delete marker");
+
+        assert!(
+            listed.contents().iter().all(|object| object.key() != Some(key)),
+            "ListObjectsV2 must hide an object whose latest version is a delete marker"
+        );
+    }
+
    #[tokio::test]
    #[serial]
    async fn test_versioning_only_delete_marker_has_minio_compatible_visibility_for_migration_proof() {
@@ -94,6 +109,7 @@ mod tests {
        assert_eq!(markers[0].version_id(), Some(delete_marker_version_id));
        assert_eq!(markers[0].is_latest(), Some(true));
        assert_current_get_is_delete_marker_not_found(&client, bucket, key).await;
+        assert_current_list_hides_delete_marker(&client, bucket, key).await;
    }

    #[tokio::test]
@@ -118,6 +134,17 @@ mod tests {
            .await
            .expect("put historical version");
        let data_version_id = put.version_id().expect("put should return data version id");
+        let listed_before_delete = client
+            .list_objects_v2()
+            .bucket(bucket)
+            .prefix(key)
+            .send()
+            .await
+            .expect("list current object before creating delete marker");
+        assert!(
+            listed_before_delete.contents().iter().any(|object| object.key() == Some(key)),
+            "ListObjectsV2 must include the current object before it is deleted"
+        );

        let delete_marker = client
            .delete_object()
@@ -145,6 +172,7 @@ mod tests {
        assert_eq!(markers[0].version_id(), Some(delete_marker_version_id));
        assert_eq!(markers[0].is_latest(), Some(true));
        assert_current_get_is_delete_marker_not_found(&client, bucket, key).await;
+        assert_current_list_hides_delete_marker(&client, bucket, key).await;

        let historical = client
            .get_object()
@@ -2136,11 +2136,20 @@ async fn four_node_manual_transition_distributed_admission_conflict_reports_stat
    assert_eq!(terminal["bucket"].as_str(), Some(bucket.as_str()));
    assert_eq!(terminal["prefix"].as_str(), Some(prefix));
    assert_eq!(terminal["dry_run"].as_bool(), Some(false));
-    assert_eq!(
-        terminal["status"].as_str(),
-        Some("partial"),
+    let terminal_status = terminal["status"].as_str();
+    assert!(
+        matches!(terminal_status, Some("partial" | "unknown")),
        "small transition queue should surface terminal backpressure: {terminal}"
    );
+    if terminal_status == Some("unknown") {
+        let failure_reason = terminal["failure_reason"]
+            .as_str()
+            .ok_or_else(|| format!("unknown terminal status omitted failure_reason: {terminal}"))?;
+        assert!(
+            failure_reason.contains("worker result was not persisted before the transition queue drained"),
+            "unknown terminal status should identify lost worker-result persistence: {terminal}"
+        );
+    }
    let skipped_queue_full = terminal["report"]["skipped_queue_full"]
        .as_u64()
        .ok_or_else(|| format!("terminal status omitted report.skipped_queue_full: {terminal}"))?;
@@ -126,7 +126,10 @@ async fn assert_key_deletion_lifecycle(base_url: &str, access_key: &str, secret_
    assert_eq!(cancelled["success"], true);
    assert_eq!(cancelled["key_metadata"]["key_state"], "Enabled");

-    let removed = kms_admin_request(
+    // A default server refuses to skip the waiting window (rustfs/backlog#1585):
+    // immediate deletion is unrecoverable and takes every object encrypted under
+    // the key with it, so the endpoint must reject it rather than honour it.
+    let refused = kms_admin_request(
        base_url,
        http::Method::DELETE,
        "/rustfs/admin/v3/kms/keys/delete",
@@ -140,37 +143,49 @@ async fn assert_key_deletion_lifecycle(base_url: &str, access_key: &str, secret_
        access_key,
        secret_key,
    )
-    .await?;
-    let removed: serde_json::Value = serde_json::from_str(&removed)?;
-    assert_eq!(removed["success"], true);
+    .await
+    .err()
+    .ok_or("immediate KMS key deletion must be refused on a default server")?;
+    assert!(
+        refused.to_string().contains("400 Bad Request"),
+        "refused immediate deletion must report a client error: {refused}"
+    );

-    let listed =
-        kms_admin_request(base_url, http::Method::GET, "/rustfs/admin/v3/kms/keys", None, access_key, secret_key).await?;
-    let listed: serde_json::Value = serde_json::from_str(&listed)?;
-    assert_eq!(listed["success"], true);
-    let keys = listed["keys"]
-        .as_array()
-        .ok_or("list KMS keys response omitted keys after deletion")?;
-    if let Some(key) = keys.iter().find(|key| key["key_id"] == key_id) {
-        assert_eq!(key["status"], "PendingDeletion", "a retained force-deleted key must be pending deletion");
-        let removed = kms_admin_request(
-            base_url,
-            http::Method::DELETE,
-            "/rustfs/admin/v3/kms/keys/delete",
-            Some(
-                &serde_json::json!({
-                    "key_id": key_id,
-                    "force_immediate": true
-                })
-                .to_string(),
-            ),
-            access_key,
-            secret_key,
-        )
-        .await?;
-        let removed: serde_json::Value = serde_json::from_str(&removed)?;
-        assert_eq!(removed["success"], true);
-    }
+    // The refused request left the key alone, so the window-bounded path still
+    // has something to schedule.
+    let described = kms_admin_request(
+        base_url,
+        http::Method::GET,
+        &format!("/rustfs/admin/v3/kms/keys/{key_id}"),
+        None,
+        access_key,
+        secret_key,
+    )
+    .await?;
+    let described: serde_json::Value = serde_json::from_str(&described)?;
+    assert_eq!(
+        described["key_metadata"]["key_state"], "Enabled",
+        "a refused immediate deletion must leave the key usable"
+    );
+
+    let rescheduled = kms_admin_request(
+        base_url,
+        http::Method::DELETE,
+        "/rustfs/admin/v3/kms/keys/delete",
+        Some(
+            &serde_json::json!({
+                "key_id": key_id,
+                "pending_window_in_days": 7
+            })
+            .to_string(),
+        ),
+        access_key,
+        secret_key,
+    )
+    .await?;
+    let rescheduled: serde_json::Value = serde_json::from_str(&rescheduled)?;
+    assert_eq!(rescheduled["success"], true);
+    assert!(rescheduled["deletion_date"].is_string());

    let listed =
        kms_admin_request(base_url, http::Method::GET, "/rustfs/admin/v3/kms/keys", None, access_key, secret_key).await?;
@@ -179,10 +194,11 @@ async fn assert_key_deletion_lifecycle(base_url: &str, access_key: &str, secret_
    let keys = listed["keys"]
        .as_array()
        .ok_or("final list KMS keys response omitted keys after deletion")?;
-    assert!(
-        keys.iter().all(|key| key["key_id"] != key_id),
-        "force-deleted KMS key must no longer appear in list"
-    );
+    let key = keys
+        .iter()
+        .find(|key| key["key_id"] == key_id)
+        .ok_or("a key awaiting its deletion window must still be listed")?;
+    assert_eq!(key["status"], "PendingDeletion", "a scheduled key must be pending deletion");
    Ok(())
 }

@@ -449,29 +449,31 @@ async fn test_vault_kms_key_crud(

    info!("✅ Delete verification: Key state correctly changed to: {}", key_state);

-    // Force Delete - Force immediate deletion for PendingDeletion key
-    let force_delete_response = crate::common::execute_awscurl(
+    // Force Delete - a default server refuses to skip the waiting window
+    // (rustfs/backlog#1585): destroying the key material immediately would take
+    // every object encrypted under the key with it.
+    let force_delete_error = crate::common::execute_awscurl(
        &format!("{base_url}/rustfs/admin/v3/kms/keys/delete?keyId={key_id}&force_immediate=true"),
        "DELETE",
        None,
        access_key,
        secret_key,
    )
-    .await?;
+    .await
+    .expect_err("Immediate KMS key deletion must be refused on a default server");
+    info!("✅ Force Delete: correctly refused for key {}: {}", key_id, force_delete_error);

-    // Parse and validate the force delete response
-    let force_delete_result: serde_json::Value = serde_json::from_str(&force_delete_response)?;
-    assert_eq!(force_delete_result["success"], true, "Force delete operation must return success=true");
-    info!("✅ Force Delete: Successfully force deleted key: {}", key_id);
+    // The refused request must leave the key exactly as it was: still present,
+    // still pending deletion, still recoverable through cancel-deletion.
+    let describe_after_refusal =
+        crate::common::awscurl_get(&format!("{base_url}/rustfs/admin/v3/kms/keys/{key_id}"), access_key, secret_key).await?;
+    let describe_after_refusal: serde_json::Value = serde_json::from_str(&describe_after_refusal)?;
+    assert_eq!(
+        describe_after_refusal["key_metadata"]["key_state"], "PendingDeletion",
+        "A refused immediate deletion must leave the key pending deletion"
+    );

-    // Verify key no longer exists after force deletion (should return error)
-    let describe_force_deleted_result =
-        crate::common::awscurl_get(&format!("{base_url}/rustfs/admin/v3/kms/keys/{key_id}"), access_key, secret_key).await;
-
-    // After force deletion, key should not be found (GET should fail)
-    assert!(describe_force_deleted_result.is_err(), "Force deleted key should not be found");
-
-    info!("✅ Force Delete verification: Key was permanently deleted and is no longer accessible");
+    info!("✅ Force Delete verification: Key survived the refused immediate deletion");

    info!("Vault KMS key CRUD operations completed successfully");
    Ok(())
@@ -26,6 +26,7 @@

 use super::common::*;
 use aws_sdk_s3::Client;
+use aws_sdk_s3::error::ProvideErrorMetadata;
 use aws_sdk_s3::primitives::{ByteStream, DateTimeFormat};
 use aws_sdk_s3::types::{
    CompletedMultipartUpload, CompletedPart, Delete, MetadataDirective, ObjectIdentifier, ObjectLockLegalHoldStatus,
@@ -2120,6 +2121,127 @@ async fn test_multipart_default_retention_fixed_at_create() {
 // Versioning Auto-Enable Tests
 // ============================================================================

+#[tokio::test]
+#[serial]
+async fn test_unretained_object_lock_object_delete_and_bucket_cleanup() {
+    init_logging();
+    info!("🧪 Test: Unretained Object Lock object delete and bucket cleanup (Issue #5339)");
+
+    let mut env = ObjectLockTestEnvironment::new()
+        .await
+        .expect("failed to create Object Lock test environment");
+    env.start_rustfs().await.expect("failed to start RustFS");
+
+    let bucket = "test-object-lock-delete-cleanup";
+    let key = "unretained-object";
+
+    env.create_object_lock_bucket(bucket)
+        .await
+        .expect("failed to create Object Lock bucket");
+    let client = env.s3_client();
+
+    let put_response = client
+        .put_object()
+        .bucket(bucket)
+        .key(key)
+        .body(ByteStream::from_static(b"unretained data"))
+        .send()
+        .await
+        .expect("failed to upload unretained object");
+    let object_version_id = put_response
+        .version_id()
+        .expect("Object Lock buckets must create versioned objects")
+        .to_string();
+
+    let delete_response = client
+        .delete_object()
+        .bucket(bucket)
+        .key(key)
+        .send()
+        .await
+        .expect("failed to create delete marker");
+    assert_eq!(delete_response.delete_marker(), Some(true));
+    let delete_marker_version_id = delete_response
+        .version_id()
+        .expect("Deleting without a version ID must create a delete marker")
+        .to_string();
+
+    let get_error = client
+        .get_object()
+        .bucket(bucket)
+        .key(key)
+        .send()
+        .await
+        .expect_err("GET must not return an object hidden by a delete marker");
+    assert_eq!(get_error.raw_response().map(|response| response.status().as_u16()), Some(404));
+    assert_eq!(get_error.as_service_error().and_then(|error| error.code()), Some("NoSuchKey"));
+
+    let listed_objects = client
+        .list_objects_v2()
+        .bucket(bucket)
+        .send()
+        .await
+        .expect("failed to list current objects");
+    assert!(
+        listed_objects.contents().iter().all(|object| object.key() != Some(key)),
+        "ListObjectsV2 must hide objects whose latest version is a delete marker"
+    );
+
+    let listed_versions = client
+        .list_object_versions()
+        .bucket(bucket)
+        .send()
+        .await
+        .expect("failed to list object versions");
+    assert!(
+        listed_versions
+            .versions()
+            .iter()
+            .any(|version| version.key() == Some(key) && version.version_id() == Some(object_version_id.as_str())),
+        "The data version must remain until it is explicitly deleted"
+    );
+    assert!(
+        listed_versions
+            .delete_markers()
+            .iter()
+            .any(|marker| marker.key() == Some(key) && marker.version_id() == Some(delete_marker_version_id.as_str())),
+        "ListObjectVersions must expose the delete marker"
+    );
+
+    client
+        .delete_object()
+        .bucket(bucket)
+        .key(key)
+        .version_id(object_version_id)
+        .send()
+        .await
+        .expect("failed to delete the data version");
+    client
+        .delete_object()
+        .bucket(bucket)
+        .key(key)
+        .version_id(delete_marker_version_id)
+        .send()
+        .await
+        .expect("failed to delete the delete marker");
+
+    let remaining_versions = client
+        .list_object_versions()
+        .bucket(bucket)
+        .send()
+        .await
+        .expect("failed to list versions after cleanup");
+    assert!(remaining_versions.versions().is_empty());
+    assert!(remaining_versions.delete_markers().is_empty());
+
+    client
+        .delete_bucket()
+        .bucket(bucket)
+        .send()
+        .await
+        .expect("Deleting every version must remove xl.meta so the bucket can be deleted normally");
+}
+
 #[tokio::test]
 #[serial]
 async fn test_versioning_auto_enabled_with_object_lock() {
@@ -15,9 +15,7 @@

 use super::{grpc_lock_client::GrpcLockClient, grpc_lock_server::spawn_lock_server};
 use rustfs_lock::client::{LockClient, local::LocalClient};
-use rustfs_lock::{
-    GlobalLockManager, LockError, LockInfo, LockRequest, LockResponse, LockStats, LockType, NamespaceLock, ObjectKey,
-};
+use rustfs_lock::{GlobalLockManager, LockInfo, LockRequest, LockResponse, LockStats, LockType, NamespaceLock, ObjectKey};
 use std::sync::Arc;
 use std::time::Duration;

@@ -35,7 +33,11 @@ struct FailingClient;
 #[async_trait::async_trait]
 impl rustfs_lock::LockClient for FailingClient {
    async fn acquire_lock(&self, _request: &rustfs_lock::LockRequest) -> rustfs_lock::Result<LockResponse> {
-        Err(LockError::internal("simulated gRPC node failure"))
+        // Match RemoteClient's transport-failure response so the coordinator can count this node toward quorum loss.
+        Ok(LockResponse::failure(
+            "Remote lock RPC failed: simulated gRPC node failure",
+            Duration::ZERO,
+        ))
    }

    async fn release(&self, _lock_id: &rustfs_lock::LockId) -> rustfs_lock::Result<bool> {
@@ -382,7 +382,6 @@ struct ManualTransitionRunReport {
    skipped_delete_marker: u64,
    skipped_directory: u64,
    skipped_replication: u64,
-    skipped_already_transitioned: u64,
    skipped_already_in_flight: u64,
    skipped_queue_full: u64,
    skipped_queue_closed: u64,
@@ -408,41 +407,6 @@ fn assert_completed_or_in_flight_partial(state: &str, report: &ManualTransitionR
    }
 }

-fn assert_conflict_winner_report(state: &str, report: &ManualTransitionRunReport, expected_objects: u64, context: &str) {
-    assert_completed_or_in_flight_partial(state, report, context);
-    if report.skipped_already_in_flight > 0 {
-        assert!(
-            report.scanned <= expected_objects,
-            "{context}: scanned more objects than the conflict scope contains: {report:#?}"
-        );
-        assert!(
-            report.eligible <= expected_objects,
-            "{context}: marked more objects eligible than the conflict scope contains: {report:#?}"
-        );
-        assert_eq!(
-            report.enqueued + report.skipped_already_in_flight,
-            report.eligible,
-            "{context}: partial in-flight accounting must cover every eligible object: {report:#?}"
-        );
-    } else {
-        assert_eq!(report.scanned, expected_objects, "{context}: {report:#?}");
-        assert_eq!(
-            report.eligible + report.skipped_already_transitioned,
-            expected_objects,
-            "{context}: {report:#?}"
-        );
-        assert_eq!(
-            report.enqueued + report.skipped_already_in_flight,
-            expected_objects,
-            "{context}: {report:#?}"
-        );
-    }
-    assert_eq!(
-        report.transition_completed, report.enqueued,
-        "{context}: winner must wait for all queued transitions: {report:#?}"
-    );
-}
-
 #[derive(Debug, Deserialize)]
 struct ManualTransitionQueueSnapshot {
    queue_capacity: u64,
@@ -1276,8 +1240,15 @@ async fn test_manual_transition_async_scope_conflicts_report_active_job() -> Tes
    cold_client.create_bucket().bucket(TIER_BUCKET).send().await?;

    let mut hot = RustFSTestEnvironment::new().await?;
-    hot.start_rustfs_server_with_env(vec![], &[("RUSTFS_SCANNER_ENABLED", "false"), ("RUSTFS_SCANNER_CYCLE", "3600")])
-        .await?;
+    hot.start_rustfs_server_with_env(
+        vec![],
+        &[
+            ("RUSTFS_SCANNER_ENABLED", "false"),
+            ("RUSTFS_SCANNER_CYCLE", "3600"),
+            (MANUAL_TRANSITION_CANCEL_BARRIER_ENV, "1"),
+        ],
+    )
+    .await?;
    let hot_client = hot.create_s3_client();
    add_rustfs_tier(&hot, &cold).await?;

@@ -1347,20 +1318,21 @@ async fn test_manual_transition_async_scope_conflicts_report_active_job() -> Tes
    assert_eq!(conflict.cancel_endpoint, status_endpoint);
    assert!(!conflict.scope_key.is_empty());

+    manual_transition_job_cancel(&hot, cancel_endpoint).await?;
+
    let terminal = wait_for_manual_transition_job_terminal(&hot, status_endpoint, MANUAL_ASYNC_CONFLICT_TERMINAL_TIMEOUT).await?;
    assert_eq!(terminal.job_id, job_id);
+    assert_eq!(terminal.status, "cancelled", "terminal conflict winner response: {terminal:#?}");
    assert!(!terminal.report.dry_run);
    assert_eq!(terminal.report.bucket, MANUAL_ASYNC_CONFLICT_BUCKET);
    assert_eq!(terminal.report.prefix, accepted.report.prefix);
-    assert_conflict_winner_report(
-        &terminal.status,
-        &terminal.report,
-        MANUAL_ASYNC_CONFLICT_OBJECTS as u64,
-        "terminal conflict winner response",
+    assert!(terminal.report.cancelled, "terminal conflict winner response: {terminal:#?}");
+    assert_eq!(terminal.report.scanned, 0, "terminal conflict winner response: {terminal:#?}");
+    assert_eq!(terminal.report.enqueued, 0, "terminal conflict winner response: {terminal:#?}");
+    assert_eq!(
+        terminal.report.transition_completed, 0,
+        "terminal conflict winner response: {terminal:#?}"
    );
-    assert_eq!(terminal.report.dry_run_eligible, 0, "terminal conflict winner response: {terminal:#?}");
-    assert_eq!(terminal.report.transition_failed, 0, "terminal conflict winner response: {terminal:#?}");
-    assert_eq!(terminal.report.tier_failure, 0, "terminal conflict winner response: {terminal:#?}");
    let after_remote_count = cold_tier_object_count(&cold_client).await?;
    assert!(after_remote_count >= before_remote_count);
    assert!(after_remote_count <= before_remote_count + MANUAL_ASYNC_CONFLICT_OBJECTS);
@@ -29,8 +29,9 @@ use aws_sdk_s3::types::{
 use aws_sdk_s3::{Client, Config};
 use base64::{Engine, engine::general_purpose::STANDARD as BASE64_STANDARD};
 use bytes::Bytes;
+use flate2::read::GzDecoder;
 use futures::{Stream, StreamExt};
-use http::header::{CONTENT_TYPE, HOST};
+use http::header::{CONTENT_ENCODING, CONTENT_TYPE, HOST};
 use http_body_util::{BodyExt, Full};
 use hyper::body::Incoming;
 use hyper::server::conn::http1;
@@ -38,6 +39,10 @@ use hyper::service::service_fn;
 use hyper::{Request, Response};
 use hyper_util::rt::TokioIo;
 use local_ip_address::local_ip;
+use opentelemetry_proto::tonic::collector::metrics::v1::ExportMetricsServiceRequest;
+use opentelemetry_proto::tonic::common::v1::{KeyValue, any_value::Value as AnyValue};
+use opentelemetry_proto::tonic::metrics::v1::{Metric, metric, number_data_point};
+use prost::Message;
 use rcgen::{
    BasicConstraints, CertificateParams, CertifiedIssuer, DnType, ExtendedKeyUsagePurpose, IsCa, KeyPair, KeyUsagePurpose,
    SanType, generate_simple_self_signed,
@@ -56,6 +61,7 @@ use sha2::{Digest, Sha256};
 use std::collections::BTreeMap;
 use std::convert::Infallible;
 use std::error::Error;
+use std::io::Read;
 use std::net::IpAddr;
 use std::path::Path;
 use std::process::Command;
@@ -64,11 +70,13 @@ use std::sync::atomic::{AtomicU64, Ordering};
 use time::{Duration as TimeDuration, OffsetDateTime};
 use tokio::fs;
 use tokio::net::TcpListener;
-use tokio::sync::watch;
+use tokio::sync::{Mutex, watch};
+use tokio::task::JoinHandle;
 use tokio::task::JoinSet;
 use tokio::time::{Duration, sleep, timeout};

 type TestResult = Result<(), Box<dyn Error + Send + Sync>>;
+type BacklogMetricPoints = Arc<Mutex<BTreeMap<String, BTreeMap<String, (u64, f64)>>>>;

 /// A replication source server validates the remote target endpoint, and the e2e
 /// target runs on loopback (127.0.0.1), which RustFS's SSRF egress guard rejects by
@@ -107,6 +115,252 @@ const REPL17_KMS_KEY_ID: &str = "repl17-local-key";
 const REPL17_SSEC_KEY: &str = "01234567890123456789012345678901";
 const REPLICATION_FAILED_EVENT: &str = "s3:Replication:OperationFailedReplication";
 const REPLICATION_EVENT_MAX_BUFFER_BYTES: usize = 1024 * 1024;
+const OTLP_METRICS_BODY_LIMIT: u64 = 4 * 1024 * 1024;
+const BUCKET_LABEL: &str = "bucket";
+const TOTAL_FAILED_COUNT_METRIC: &str = "rustfs_bucket_replication_total_failed_count";
+const CURRENT_BACKLOG_COUNT_METRIC: &str = "rustfs_bucket_replication_current_backlog_count";
+const CURRENT_BACKLOG_BYTES_METRIC: &str = "rustfs_bucket_replication_current_backlog_bytes";
+const MRF_PENDING_COUNT_METRIC: &str = "rustfs_bucket_replication_mrf_pending_count";
+const MRF_PENDING_BYTES_METRIC: &str = "rustfs_bucket_replication_mrf_pending_bytes";
+
+struct ReplicationBacklogMetricCollector {
+    endpoint: String,
+    values: BacklogMetricPoints,
+    task: JoinHandle<()>,
+}
+
+impl ReplicationBacklogMetricCollector {
+    async fn start() -> Result<Self, Box<dyn Error + Send + Sync>> {
+        let listener = TcpListener::bind("127.0.0.1:0").await?;
+        let endpoint = format!("http://{}/v1/metrics", listener.local_addr()?);
+        let values = Arc::new(Mutex::new(BTreeMap::new()));
+        let task_values = values.clone();
+        let task = tokio::spawn(async move {
+            loop {
+                let Ok((stream, _)) = listener.accept().await else {
+                    break;
+                };
+                let values = task_values.clone();
+                tokio::spawn(async move {
+                    let _ = http1::Builder::new()
+                        .serve_connection(
+                            TokioIo::new(stream),
+                            service_fn(move |request| handle_backlog_metric_export(request, values.clone())),
+                        )
+                        .await;
+                });
+            }
+        });
+
+        Ok(Self { endpoint, values, task })
+    }
+
+    fn root_endpoint(&self) -> &str {
+        self.endpoint.trim_end_matches("/v1/metrics")
+    }
+
+    async fn bucket_metric_value(&self, metric: &str, bucket: &str) -> f64 {
+        self.values
+            .lock()
+            .await
+            .get(metric)
+            .and_then(|buckets| buckets.get(bucket))
+            .map(|(_, value)| *value)
+            .unwrap_or_default()
+    }
+
+    async fn wait_for_bucket_metric(
+        &self,
+        metric: &str,
+        bucket: &str,
+        expected: impl Fn(f64) -> bool,
+        description: &str,
+    ) -> Result<f64, Box<dyn Error + Send + Sync>> {
+        let deadline = tokio::time::Instant::now() + Duration::from_secs(30);
+        loop {
+            let value = self.bucket_metric_value(metric, bucket).await;
+            if expected(value) {
+                return Ok(value);
+            }
+            if tokio::time::Instant::now() >= deadline {
+                let snapshot = self.values.lock().await.clone();
+                return Err(format!("timed out waiting for {metric} on bucket {bucket} to satisfy {description}; last={value}, snapshot={snapshot:?}").into());
+            }
+            sleep(Duration::from_millis(200)).await;
+        }
+    }
+}
+
+impl Drop for ReplicationBacklogMetricCollector {
+    fn drop(&mut self) {
+        self.task.abort();
+    }
+}
+
+async fn handle_backlog_metric_export(
+    request: Request<Incoming>,
+    values: BacklogMetricPoints,
+) -> Result<Response<Full<Bytes>>, Infallible> {
+    if request.uri().path() != "/v1/metrics" {
+        return Ok(empty_http_response(StatusCode::NOT_FOUND));
+    }
+
+    let gzip = request
+        .headers()
+        .get(CONTENT_ENCODING)
+        .and_then(|value| value.to_str().ok())
+        .is_some_and(|value| value.eq_ignore_ascii_case("gzip"));
+    let Ok(collected) = request.into_body().collect().await else {
+        return Ok(empty_http_response(StatusCode::BAD_REQUEST));
+    };
+    let body = collected.to_bytes();
+    if body.len() as u64 > OTLP_METRICS_BODY_LIMIT {
+        return Ok(empty_http_response(StatusCode::PAYLOAD_TOO_LARGE));
+    }
+    let payload = if gzip {
+        let mut decoder = GzDecoder::new(body.as_ref());
+        let mut decoded = Vec::new();
+        if decoder
+            .by_ref()
+            .take(OTLP_METRICS_BODY_LIMIT + 1)
+            .read_to_end(&mut decoded)
+            .is_err()
+            || decoded.len() as u64 > OTLP_METRICS_BODY_LIMIT
+        {
+            return Ok(empty_http_response(StatusCode::BAD_REQUEST));
+        }
+        decoded
+    } else {
+        body.to_vec()
+    };
+
+    match ExportMetricsServiceRequest::decode(payload.as_slice()) {
+        Ok(export) => {
+            let mut values = values.lock().await;
+            record_backlog_metrics(&export, &mut values);
+            Ok(empty_http_response(StatusCode::OK))
+        }
+        Err(_) => Ok(empty_http_response(StatusCode::BAD_REQUEST)),
+    }
+}
+
+fn empty_http_response(status: StatusCode) -> Response<Full<Bytes>> {
+    Response::builder()
+        .status(status)
+        .body(Full::new(Bytes::new()))
+        .expect("static HTTP response is valid")
+}
+
+fn record_backlog_metrics(export: &ExportMetricsServiceRequest, values: &mut BTreeMap<String, BTreeMap<String, (u64, f64)>>) {
+    for resource_metrics in &export.resource_metrics {
+        for scope_metrics in &resource_metrics.scope_metrics {
+            for metric in &scope_metrics.metrics {
+                record_backlog_metric(metric, values);
+            }
+        }
+    }
+}
+
+fn record_backlog_metric(metric: &Metric, values: &mut BTreeMap<String, BTreeMap<String, (u64, f64)>>) {
+    if ![
+        TOTAL_FAILED_COUNT_METRIC,
+        CURRENT_BACKLOG_COUNT_METRIC,
+        CURRENT_BACKLOG_BYTES_METRIC,
+        MRF_PENDING_COUNT_METRIC,
+        MRF_PENDING_BYTES_METRIC,
+    ]
+    .contains(&metric.name.as_str())
+    {
+        return;
+    }
+
+    let points = match &metric.data {
+        Some(metric::Data::Gauge(gauge)) => gauge.data_points.as_slice(),
+        Some(metric::Data::Sum(sum)) => sum.data_points.as_slice(),
+        _ => return,
+    };
+    for point in points {
+        let Some(bucket) = attribute_string(&point.attributes, BUCKET_LABEL) else {
+            continue;
+        };
+        let Some(value) = number_point_value(point.value.as_ref()) else {
+            continue;
+        };
+        values
+            .entry(metric.name.clone())
+            .or_default()
+            .entry(bucket.to_string())
+            .and_modify(|current| {
+                if point.time_unix_nano >= current.0 {
+                    *current = (point.time_unix_nano, value);
+                }
+            })
+            .or_insert((point.time_unix_nano, value));
+    }
+}
+
+fn number_point_value(value: Option<&number_data_point::Value>) -> Option<f64> {
+    match value? {
+        number_data_point::Value::AsDouble(value) => Some(*value),
+        number_data_point::Value::AsInt(value) => Some(*value as f64),
+    }
+}
+
+fn attribute_string<'a>(attributes: &'a [KeyValue], wanted_key: &str) -> Option<&'a str> {
+    attributes.iter().find_map(|attribute| {
+        if attribute.key != wanted_key {
+            return None;
+        }
+        match attribute.value.as_ref()?.value.as_ref()? {
+            AnyValue::StringValue(value) => Some(value.as_str()),
+            _ => None,
+        }
+    })
+}
+
+struct SlowReplicationTargetGuard {
+    task: Option<JoinHandle<()>>,
+}
+
+impl SlowReplicationTargetGuard {
+    async fn bind(address: &str, response_delay: Duration) -> Result<Self, Box<dyn Error + Send + Sync>> {
+        let listener = TcpListener::bind(address).await?;
+        let task = tokio::spawn(async move {
+            loop {
+                let Ok((stream, _)) = listener.accept().await else {
+                    break;
+                };
+                tokio::spawn(async move {
+                    let _ = http1::Builder::new()
+                        .serve_connection(
+                            TokioIo::new(stream),
+                            service_fn(move |_request| async move {
+                                sleep(response_delay).await;
+                                Ok::<_, Infallible>(empty_http_response(StatusCode::SERVICE_UNAVAILABLE))
+                            }),
+                        )
+                        .await;
+                });
+            }
+        });
+        Ok(Self { task: Some(task) })
+    }
+
+    async fn stop(mut self) {
+        if let Some(task) = self.task.take() {
+            task.abort();
+            let _ = task.await;
+        }
+    }
+}
+
+impl Drop for SlowReplicationTargetGuard {
+    fn drop(&mut self) {
+        if let Some(task) = self.task.take() {
+            task.abort();
+        }
+    }
+}

 #[derive(Debug, Clone, serde::Deserialize)]
 struct ReplicationResetStatusResponse {
@@ -3659,6 +3913,139 @@ async fn test_bucket_replication_recovers_after_target_outage() -> TestResult {
    Ok(())
 }

+/// backlog#1610 - black-box bucket replication backlog observability.
+///
+/// The source exports metrics through the same OTLP path production uses. A slow
+/// loopback target keeps replication workers occupied long enough for the metrics
+/// runtime to publish non-zero bucket backlog gauges; after the real target
+/// returns, replication must converge and the exported current/MRF pending gauges
+/// must settle back to zero even though the historical failed counter remains
+/// non-zero.
+#[tokio::test]
+#[serial]
+async fn test_bucket_replication_backlog_metrics_observe_outage_and_recovery() -> TestResult {
+    init_logging();
+
+    let collector = ReplicationBacklogMetricCollector::start().await?;
+    let mut source_env = RustFSTestEnvironment::new().await?;
+    let metric_root = collector.root_endpoint().to_string();
+    let metric_endpoint = collector.endpoint.clone();
+    let mut source_env_vars: Vec<(&str, &str)> = replication_fast_env().into_iter().collect();
+    source_env_vars.extend_from_slice(LOOPBACK_REPLICATION_TARGET_ENV);
+    source_env_vars.extend_from_slice(FAST_SCANNER_ENV);
+    source_env_vars.extend_from_slice(&[
+        ("RUSTFS_OBS_ENDPOINT", metric_root.as_str()),
+        ("RUSTFS_OBS_METRIC_ENDPOINT", metric_endpoint.as_str()),
+        ("RUSTFS_OBS_METRICS_EXPORT_ENABLED", "true"),
+        ("RUSTFS_OBS_TRACES_EXPORT_ENABLED", "false"),
+        ("RUSTFS_OBS_LOGS_EXPORT_ENABLED", "false"),
+        ("RUSTFS_OBS_METER_INTERVAL", "1"),
+        ("RUSTFS_OBS_USE_STDOUT", "false"),
+        ("RUSTFS_METRICS_BUCKET_REPLICATION_BANDWIDTH_INTERVAL_SEC", "1"),
+    ]);
+    source_env.start_rustfs_server_with_env(vec![], &source_env_vars).await?;
+
+    let mut target_env = RustFSTestEnvironment::new().await?;
+    target_env.start_rustfs_server_without_cleanup(vec![]).await?;
+
+    let source_bucket = "repl-backlog-metrics-src";
+    let target_bucket = "repl-backlog-metrics-dst";
+    let source_client = source_env.create_s3_client();
+    let target_client = target_env.create_s3_client();
+
+    source_client.create_bucket().bucket(source_bucket).send().await?;
+    target_client.create_bucket().bucket(target_bucket).send().await?;
+    enable_bucket_versioning(&source_env, source_bucket).await?;
+    enable_bucket_versioning(&target_env, target_bucket).await?;
+
+    let target_arn = set_replication_target(&source_env, source_bucket, &target_env, target_bucket).await?;
+    put_bucket_replication(&source_env, source_bucket, &target_arn).await?;
+
+    source_client
+        .put_object()
+        .bucket(source_bucket)
+        .key("before-outage.txt")
+        .body(ByteStream::from_static(b"baseline written before backlog metrics outage"))
+        .send()
+        .await?;
+    assert_replication_converged(&source_client, source_bucket, &target_client, target_bucket).await?;
+
+    target_env.stop_server();
+    let slow_target = SlowReplicationTargetGuard::bind(&target_env.address, Duration::from_secs(5)).await?;
+
+    let outage_keys = ["metrics-outage-1.txt", "metrics-outage-2.txt", "metrics-outage-3.txt"];
+    for key in outage_keys {
+        source_client
+            .put_object()
+            .bucket(source_bucket)
+            .key(key)
+            .body(ByteStream::from(
+                format!("written while backlog metrics target was slow: {key}").into_bytes(),
+            ))
+            .send()
+            .await?;
+    }
+
+    let current_backlog = collector
+        .wait_for_bucket_metric(
+            CURRENT_BACKLOG_COUNT_METRIC,
+            source_bucket,
+            |value| value >= 1.0,
+            "be at least 1 during outage",
+        )
+        .await?;
+    let current_bytes = collector
+        .wait_for_bucket_metric(
+            CURRENT_BACKLOG_BYTES_METRIC,
+            source_bucket,
+            |value| value > 0.0,
+            "report bytes during outage",
+        )
+        .await?;
+    assert!(
+        current_bytes >= current_backlog,
+        "backlog bytes should be at least the object count while queued; count={current_backlog}, bytes={current_bytes}"
+    );
+    let failed_count = collector
+        .wait_for_bucket_metric(
+            TOTAL_FAILED_COUNT_METRIC,
+            source_bucket,
+            |value| value >= 1.0,
+            "record at least one failed replication attempt during outage",
+        )
+        .await?;
+
+    slow_target.stop().await;
+    target_env.restart_server_preserving_data(vec![], &[]).await?;
+
+    assert_replication_converged(&source_client, source_bucket, &target_client, target_bucket).await?;
+    for metric in [
+        CURRENT_BACKLOG_COUNT_METRIC,
+        CURRENT_BACKLOG_BYTES_METRIC,
+        MRF_PENDING_COUNT_METRIC,
+        MRF_PENDING_BYTES_METRIC,
+    ] {
+        collector
+            .wait_for_bucket_metric(metric, source_bucket, |value| value == 0.0, "settle back to zero after recovery")
+            .await?;
+    }
+    let final_failed_count = collector.bucket_metric_value(TOTAL_FAILED_COUNT_METRIC, source_bucket).await;
+    assert!(
+        final_failed_count >= failed_count,
+        "historical failed counter should remain non-zero after recovery while current backlog is zero; before={failed_count}, after={final_failed_count}"
+    );
+
+    let target_state = list_replication_state(&target_client, target_bucket).await?;
+    for key in ["before-outage.txt"].into_iter().chain(outage_keys) {
+        assert!(
+            target_state.iter().any(|entry| entry.key == key && !entry.delete_marker),
+            "target missing object {key} after backlog metrics recovery; state={target_state:?}"
+        );
+    }
+
+    Ok(())
+}
+
 /// backlog#1147 repl-5, scenario (b) — failure state survives a source restart
 /// (mirrors backlog#858 delete-decision re-derivation and #859 no-drop).
 ///
@@ -12,22 +12,35 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.

-use crate::common::{RustFSTestEnvironment, init_logging, local_http_client};
+use crate::common::{RustFSTestEnvironment, admin_ok, init_logging};
 use aws_sdk_sts::config::retry::RetryConfig;
 use aws_sdk_sts::config::{Credentials, Region};
 use aws_sdk_sts::error::ProvideErrorMetadata;
 use aws_sdk_sts::operation::RequestId;
 use aws_sdk_sts::{Client, Config};
 use aws_smithy_http_client::Builder as SmithyHttpClientBuilder;
-use http::header::{CONTENT_TYPE, HOST};
-use rustfs_signer::constants::UNSIGNED_PAYLOAD;
-use rustfs_signer::sign_v4;
-use s3s::Body;
+use bytes::Bytes;
+use http::header::{AUTHORIZATION, CONTENT_TYPE};
+use http::{Request, Response};
+use http_body_util::{BodyExt, Full};
+use hyper::body::Incoming;
+use hyper::server::conn::http1;
+use hyper::service::service_fn;
+use hyper_util::rt::TokioIo;
+use serde_json::Value;
 use serial_test::serial;
+use std::collections::BTreeSet;
+use std::convert::Infallible;
 use std::error::Error;
+use std::sync::Arc;
+use tokio::net::TcpListener;
+use tokio::sync::{Notify, mpsc};
+use tokio::task::{JoinHandle, JoinSet};
+use tokio::time::{Duration, timeout};

 type BoxError = Box<dyn Error + Send + Sync>;
 type TestResult = Result<(), BoxError>;
+const OPA_AUTH_TOKEN: &str = "sts-opa-token";

 fn sts_client(url: &str, access_key: &str, secret_key: &str, session_token: Option<&str>) -> Client {
    let mut config = Config::builder()
@@ -49,32 +62,14 @@ fn sts_client(url: &str, access_key: &str, secret_key: &str, session_token: Opti
 }

 async fn create_root_service_account(env: &RustFSTestEnvironment) -> Result<(String, String), BoxError> {
-    let path = "/rustfs/admin/v3/add-service-accounts";
-    let url = format!("{}{path}", env.url);
-    let uri = url.parse::<http::Uri>()?;
-    let authority = uri.authority().ok_or("admin URL missing authority")?.to_string();
-    let body = serde_json::json!({ "targetUser": env.access_key.clone() }).to_string();
-    let request = http::Request::builder()
-        .method(http::Method::PUT)
-        .uri(uri)
-        .header(HOST, authority)
-        .header(CONTENT_TYPE, "application/json")
-        .header("x-amz-content-sha256", UNSIGNED_PAYLOAD)
-        .body(Body::empty())?;
-    let content_length = i64::try_from(body.len()).map_err(|_| "service account request body is too large")?;
-    let signed = sign_v4(request, content_length, &env.access_key, &env.secret_key, "", "us-east-1");
-    let mut request = local_http_client().put(&url);
-    for (name, value) in signed.headers() {
-        request = request.header(name, value);
-    }
-    let response = request.body(body).send().await?;
-    let status = response.status();
-    let body = response.text().await?;
-    if !status.is_success() {
-        return Err(format!("create service account failed: {status} {body}").into());
-    }
-
-    let response: serde_json::Value = serde_json::from_str(&body)?;
+    let body = admin_ok(
+        env,
+        http::Method::PUT,
+        "/rustfs/admin/v3/add-service-accounts",
+        Some(serde_json::json!({ "targetUser": env.access_key.clone() }).to_string()),
+    )
+    .await?;
+    let response: Value = serde_json::from_str(&body)?;
    let access_key = response["credentials"]["accessKey"]
        .as_str()
        .ok_or("service account response should contain credentials.accessKey")?
@@ -86,28 +81,237 @@ async fn create_root_service_account(env: &RustFSTestEnvironment) -> Result<(Str
    Ok((access_key, secret_key))
 }

-async fn assert_chaining_denied(client: &Client, credential_kind: &str) -> TestResult {
+async fn create_user_with_policy(
+    env: &RustFSTestEnvironment,
+    user: &str,
+    secret: &str,
+    policy_name: &str,
+    statements: Value,
+) -> TestResult {
+    create_user(env, user, secret).await?;
+    admin_ok(
+        env,
+        http::Method::PUT,
+        &format!("/rustfs/admin/v3/add-canned-policy?name={policy_name}"),
+        Some(
+            serde_json::json!({
+                "Version": "2012-10-17",
+                "Statement": statements,
+            })
+            .to_string(),
+        ),
+    )
+    .await?;
+    admin_ok(
+        env,
+        http::Method::POST,
+        "/rustfs/admin/v3/idp/builtin/policy/attach",
+        Some(serde_json::json!({ "policies": [policy_name], "user": user }).to_string()),
+    )
+    .await?;
+    Ok(())
+}
+
+async fn create_user(env: &RustFSTestEnvironment, user: &str, secret: &str) -> TestResult {
+    admin_ok(
+        env,
+        http::Method::PUT,
+        &format!("/rustfs/admin/v3/add-user?accessKey={user}"),
+        Some(serde_json::json!({ "secretKey": secret, "status": "enabled" }).to_string()),
+    )
+    .await?;
+    Ok(())
+}
+
+async fn assert_access_denied(client: &Client, context: &str) -> TestResult {
    let error = client
        .assume_role()
        .role_arn("arn:aws:iam::123456789012:role/test")
        .role_session_name("sts-query-compat-e2e")
        .send()
        .await
-        .expect_err("credential chaining must be denied");
+        .expect_err("AssumeRole must be denied");
    let service_error = error
        .as_service_error()
-        .ok_or_else(|| format!("{credential_kind} denial should deserialize as an STS service error: {error:?}"))?;
+        .ok_or_else(|| format!("{context} should deserialize as an STS service error: {error:?}"))?;

    assert_eq!(error.raw_response().map(|response| response.status().as_u16()), Some(403));
    assert_eq!(service_error.code(), Some("AccessDenied"));
    assert_eq!(service_error.message(), Some("Access Denied"));
    assert!(
        error.request_id().is_some_and(|request_id| !request_id.is_empty()),
-        "{credential_kind} denial should include a request ID"
+        "{context} should include a request ID"
    );
    Ok(())
 }

+async fn handle_opa_request(
+    request: Request<Incoming>,
+    requests: mpsc::UnboundedSender<Value>,
+    validation_started: mpsc::UnboundedSender<()>,
+    validation_mode: OpaValidationMode,
+    expected_authorization: Option<String>,
+) -> Result<Response<Full<Bytes>>, Infallible> {
+    if let Some(expected_authorization) = expected_authorization
+        && request.headers().get(AUTHORIZATION).and_then(|value| value.to_str().ok()) != Some(expected_authorization.as_str())
+    {
+        return Ok(Response::builder()
+            .status(401)
+            .body(Full::new(Bytes::new()))
+            .expect("static OPA unauthorized response must be valid"));
+    }
+
+    let body = match request.into_body().collect().await {
+        Ok(body) => body.to_bytes(),
+        Err(error) => {
+            return Ok(Response::builder()
+                .status(400)
+                .body(Full::new(Bytes::from(error.to_string())))
+                .expect("static OPA error response must be valid"));
+        }
+    };
+
+    let payload = if body.is_empty() {
+        None
+    } else {
+        match serde_json::from_slice::<Value>(&body) {
+            Ok(payload) => Some(payload),
+            Err(error) => {
+                return Ok(Response::builder()
+                    .status(400)
+                    .body(Full::new(Bytes::from(error.to_string())))
+                    .expect("static OPA error response must be valid"));
+            }
+        }
+    };
+    if payload.is_none() {
+        let _ = validation_started.send(());
+        if let OpaValidationMode::DelayedUnavailable(release) = validation_mode {
+            release.notified().await;
+            return Ok(Response::builder()
+                .status(503)
+                .body(Full::new(Bytes::new()))
+                .expect("static OPA unavailable response must be valid"));
+        }
+    }
+    let allow = match payload.as_ref().and_then(|value| value.pointer("/input/identity/account")) {
+        Some(Value::String(account)) if account == "opaallow" => payload
+            .as_ref()
+            .and_then(|value| value.pointer("/input/context/deny_only"))
+            .and_then(Value::as_bool)
+            .unwrap_or(false),
+        Some(Value::String(account)) if account == "opadeny" => false,
+        None => true,
+        _ => false,
+    };
+    if let Some(payload) = payload {
+        let _ = requests.send(payload);
+    }
+    let body =
+        serde_json::to_vec(&serde_json::json!({ "result": { "allow": allow } })).expect("static OPA response must serialize");
+    Ok(Response::builder()
+        .header(CONTENT_TYPE, "application/json")
+        .body(Full::new(Bytes::from(body)))
+        .expect("static OPA response must be valid"))
+}
+
+#[derive(Clone)]
+enum OpaValidationMode {
+    Ready,
+    DelayedUnavailable(Arc<Notify>),
+}
+
+struct OpaMock {
+    url: String,
+    requests: mpsc::UnboundedReceiver<Value>,
+    validation_started: mpsc::UnboundedReceiver<()>,
+    validation_release: Option<Arc<Notify>>,
+    task: JoinHandle<()>,
+}
+
+impl OpaMock {
+    async fn start() -> Result<Self, BoxError> {
+        Self::start_with_mode(OpaValidationMode::Ready, Some(OPA_AUTH_TOKEN)).await
+    }
+
+    async fn start_delayed_unavailable() -> Result<Self, BoxError> {
+        let release = Arc::new(Notify::new());
+        Self::start_with_mode(OpaValidationMode::DelayedUnavailable(release), None).await
+    }
+
+    async fn start_with_mode(validation_mode: OpaValidationMode, auth_token: Option<&str>) -> Result<Self, BoxError> {
+        let listener = TcpListener::bind("127.0.0.1:0").await?;
+        let url = format!("http://{}/v1/data/rustfs/authz/allow", listener.local_addr()?);
+        let (requests_tx, requests) = mpsc::unbounded_channel();
+        let (validation_started_tx, validation_started) = mpsc::unbounded_channel();
+        let expected_authorization = auth_token.map(|token| format!("Bearer {token}"));
+        let validation_release = match &validation_mode {
+            OpaValidationMode::Ready => None,
+            OpaValidationMode::DelayedUnavailable(release) => Some(Arc::clone(release)),
+        };
+        let task = tokio::spawn(async move {
+            let mut connections = JoinSet::new();
+            loop {
+                tokio::select! {
+                    accepted = listener.accept() => {
+                        let Ok((stream, _)) = accepted else { break };
+                        let requests = requests_tx.clone();
+                        let validation_started = validation_started_tx.clone();
+                        let validation_mode = validation_mode.clone();
+                        let expected_authorization = expected_authorization.clone();
+                        connections.spawn(async move {
+                            let handler = service_fn(move |request| {
+                                handle_opa_request(
+                                    request,
+                                    requests.clone(),
+                                    validation_started.clone(),
+                                    validation_mode.clone(),
+                                    expected_authorization.clone(),
+                                )
+                            });
+                            let _ = http1::Builder::new()
+                                .serve_connection(TokioIo::new(stream), handler)
+                                .await;
+                        });
+                    }
+                    _ = connections.join_next(), if !connections.is_empty() => {}
+                }
+            }
+        });
+        Ok(Self {
+            url,
+            requests,
+            validation_started,
+            validation_release,
+            task,
+        })
+    }
+
+    async fn next_request(&mut self) -> Result<Value, BoxError> {
+        timeout(Duration::from_secs(5), self.requests.recv())
+            .await?
+            .ok_or_else(|| "OPA request channel closed".into())
+    }
+
+    async fn wait_for_validation(&mut self) -> TestResult {
+        timeout(Duration::from_secs(5), self.validation_started.recv())
+            .await?
+            .ok_or_else(|| "OPA validation channel closed".into())
+    }
+
+    fn release_validation(&self) {
+        if let Some(release) = &self.validation_release {
+            release.notify_one();
+        }
+    }
+}
+
+impl Drop for OpaMock {
+    fn drop(&mut self) {
+        self.task.abort();
+    }
+}
+
 #[tokio::test]
 #[serial]
 async fn test_sts_query_responses_are_aws_sdk_compatible() -> TestResult {
@@ -155,7 +359,7 @@ async fn test_sts_query_responses_are_aws_sdk_compatible() -> TestResult {
        "signature rejection should include a request ID"
    );

-    assert_chaining_denied(
+    assert_access_denied(
        &sts_client(
            &env.url,
            temporary.access_key_id(),
@@ -167,7 +371,187 @@ async fn test_sts_query_responses_are_aws_sdk_compatible() -> TestResult {
    .await?;

    let (service_access_key, service_secret_key) = create_root_service_account(&env).await?;
-    assert_chaining_denied(&sts_client(&env.url, &service_access_key, &service_secret_key, None), "service account").await?;
+    assert_access_denied(
+        &sts_client(&env.url, &service_access_key, &service_secret_key, None),
+        "service-account denial",
+    )
+    .await?;
+
+    let implicit_user = "stsimplicit";
+    let explicit_allow_user = "stsallow";
+    let explicit_deny_user = "stsdeny";
+    let policyless_user = "stspolicyless";
+    let secret = "stsAuthzSecret123";
+    create_user(&env, policyless_user, secret).await?;
+    assert_access_denied(&sts_client(&env.url, policyless_user, secret, None), "policyless user").await?;
+    create_user_with_policy(
+        &env,
+        implicit_user,
+        secret,
+        "sts-implicit-policy",
+        serde_json::json!([{
+            "Effect": "Allow",
+            "Action": ["s3:ListAllMyBuckets"],
+            "Resource": ["arn:aws:s3:::*"],
+        }]),
+    )
+    .await?;
+    create_user_with_policy(
+        &env,
+        explicit_allow_user,
+        secret,
+        "sts-allow-policy",
+        serde_json::json!([{
+            "Effect": "Allow",
+            "Action": ["sts:AssumeRole"],
+            "Resource": ["arn:aws:s3:::*"],
+        }]),
+    )
+    .await?;
+    create_user_with_policy(
+        &env,
+        explicit_deny_user,
+        secret,
+        "sts-deny-policy",
+        serde_json::json!([
+            {
+                "Effect": "Allow",
+                "Action": ["sts:AssumeRole"],
+                "Resource": ["arn:aws:s3:::*"],
+            },
+            {
+                "Effect": "Deny",
+                "Action": ["sts:AssumeRole"],
+                "Resource": ["arn:aws:s3:::*"],
+            }
+        ]),
+    )
+    .await?;
+
+    for user in [implicit_user, explicit_allow_user] {
+        let output = sts_client(&env.url, user, secret, None)
+            .assume_role()
+            .role_arn("arn:aws:iam::123456789012:role/test")
+            .role_session_name("sts-authz-e2e")
+            .send()
+            .await
+            .map_err(|error| format!("{user} should be allowed to call AssumeRole: {error:?}"))?;
+        let credentials = output
+            .credentials()
+            .ok_or_else(|| format!("{user} AssumeRole response should contain credentials"))?;
+        assert!(!credentials.access_key_id().is_empty());
+        assert!(!credentials.secret_access_key().is_empty());
+        assert!(!credentials.session_token().is_empty());
+    }
+    assert_access_denied(&sts_client(&env.url, explicit_deny_user, secret, None), "explicit sts:AssumeRole Deny").await?;
+
+    env.stop_server();
+    Ok(())
+}
+
+#[tokio::test]
+#[serial]
+async fn test_sts_assume_role_opa_contract() -> TestResult {
+    init_logging();
+
+    let mut opa = OpaMock::start().await?;
+    let mut env = RustFSTestEnvironment::new().await?;
+    env.start_rustfs_server_with_env(
+        vec![],
+        &[
+            ("RUSTFS_POLICY_PLUGIN_URL", opa.url.as_str()),
+            ("RUSTFS_POLICY_PLUGIN_AUTH_TOKEN", OPA_AUTH_TOKEN),
+        ],
+    )
+    .await?;
+
+    let secret = "stsOpaSecret123";
+    create_user_with_policy(
+        &env,
+        "opaallow",
+        secret,
+        "sts-opa-local-deny-policy",
+        serde_json::json!([{
+            "Effect": "Deny",
+            "Action": ["sts:AssumeRole"],
+            "Resource": ["arn:aws:s3:::*"],
+        }]),
+    )
+    .await?;
+    create_user_with_policy(
+        &env,
+        "opadeny",
+        secret,
+        "sts-opa-local-allow-policy",
+        serde_json::json!([{
+            "Effect": "Allow",
+            "Action": ["sts:AssumeRole"],
+            "Resource": ["arn:aws:s3:::*"],
+        }]),
+    )
+    .await?;
+
+    sts_client(&env.url, "opaallow", secret, None)
+        .assume_role()
+        .role_arn("arn:aws:iam::123456789012:role/test")
+        .role_session_name("sts-opa-contract")
+        .send()
+        .await
+        .map_err(|error| format!("OPA allow should override the local explicit Deny: {error:?}"))?;
+    assert_access_denied(
+        &sts_client(&env.url, "opadeny", secret, None),
+        "OPA denial despite local sts:AssumeRole Allow",
+    )
+    .await?;
+
+    let mut accounts = BTreeSet::new();
+    for _ in 0..2 {
+        let request = opa.next_request().await?;
+        assert_eq!(request.pointer("/input/action").and_then(Value::as_str), Some("sts:AssumeRole"));
+        assert_eq!(request.pointer("/input/context/deny_only").and_then(Value::as_bool), Some(true));
+        let account = request
+            .pointer("/input/identity/account")
+            .and_then(Value::as_str)
+            .ok_or("OPA input should include identity.account")?;
+        accounts.insert(account.to_owned());
+    }
+    assert_eq!(accounts, BTreeSet::from(["opaallow".to_owned(), "opadeny".to_owned()]));
+
+    env.stop_server();
+    Ok(())
+}
+
+#[tokio::test]
+#[serial]
+async fn test_sts_assume_role_fails_closed_while_opa_is_unavailable() -> TestResult {
+    init_logging();
+
+    let mut opa = OpaMock::start_delayed_unavailable().await?;
+    let mut env = RustFSTestEnvironment::new().await?;
+    env.start_rustfs_server_with_env(vec![], &[("RUSTFS_POLICY_PLUGIN_URL", opa.url.as_str())])
+        .await?;
+    opa.wait_for_validation().await?;
+
+    let user = "opaunavailable";
+    let secret = "stsOpaUnavailableSecret123";
+    create_user_with_policy(
+        &env,
+        user,
+        secret,
+        "sts-opa-unavailable-local-policy",
+        serde_json::json!([{
+            "Effect": "Allow",
+            "Action": ["s3:ListAllMyBuckets"],
+            "Resource": ["arn:aws:s3:::*"],
+        }]),
+    )
+    .await?;
+
+    assert_access_denied(&sts_client(&env.url, user, secret, None), "configured OPA initialization").await?;
+
+    opa.release_validation();
+    tokio::time::sleep(Duration::from_millis(200)).await;
+    assert_access_denied(&sts_client(&env.url, user, secret, None), "configured OPA validation failure").await?;

    env.stop_server();
    Ok(())
@@ -33,14 +33,98 @@ workspace = true
 [features]
 default = []
 rio-v2 = ["dep:rustfs-rio-v2"]
-hotpath = ["dep:hotpath", "hotpath/hotpath", "rustfs-filemeta/hotpath", "rustfs-rio/hotpath"]
+hotpath = [
+    "hotpath/hotpath",
+    "hotpath/tokio",
+    "hotpath/futures",
+    "hotpath/async-channel",
+    "hotpath/parking_lot",
+    "hotpath/reqwest-0-13",
+    "rustfs-checksums/hotpath",
+    "rustfs-common/hotpath",
+    "rustfs-concurrency/hotpath",
+    "rustfs-config/hotpath",
+    "rustfs-credentials/hotpath",
+    "rustfs-data-usage/hotpath",
+    "rustfs-filemeta/hotpath",
+    "rustfs-io-metrics/hotpath",
+    "rustfs-lifecycle/hotpath",
+    "rustfs-lock/hotpath",
+    "rustfs-madmin/hotpath",
+    "rustfs-object-capacity/hotpath",
+    "rustfs-policy/hotpath",
+    "rustfs-protos/hotpath",
+    "rustfs-replication/hotpath",
+    "rustfs-rio/hotpath",
+    "rustfs-rio-v2?/hotpath",
+    "rustfs-s3-types/hotpath",
+    "rustfs-signer/hotpath",
+    "rustfs-storage-api/hotpath",
+    "rustfs-tls-runtime/hotpath",
+    "rustfs-utils/hotpath",
+    "rustfs-crypto/hotpath",
+]
+hotpath-alloc = [
+    "hotpath",
+    "hotpath/hotpath-alloc",
+    "rustfs-checksums/hotpath-alloc",
+    "rustfs-common/hotpath-alloc",
+    "rustfs-concurrency/hotpath-alloc",
+    "rustfs-config/hotpath-alloc",
+    "rustfs-credentials/hotpath-alloc",
+    "rustfs-data-usage/hotpath-alloc",
+    "rustfs-filemeta/hotpath-alloc",
+    "rustfs-io-metrics/hotpath-alloc",
+    "rustfs-lifecycle/hotpath-alloc",
+    "rustfs-lock/hotpath-alloc",
+    "rustfs-madmin/hotpath-alloc",
+    "rustfs-object-capacity/hotpath-alloc",
+    "rustfs-policy/hotpath-alloc",
+    "rustfs-protos/hotpath-alloc",
+    "rustfs-replication/hotpath-alloc",
+    "rustfs-rio/hotpath-alloc",
+    "rustfs-rio-v2?/hotpath-alloc",
+    "rustfs-s3-types/hotpath-alloc",
+    "rustfs-signer/hotpath-alloc",
+    "rustfs-storage-api/hotpath-alloc",
+    "rustfs-tls-runtime/hotpath-alloc",
+    "rustfs-utils/hotpath-alloc",
+    "rustfs-crypto/hotpath-alloc",
+]
+hotpath-cpu = [
+    "hotpath",
+    "hotpath/hotpath-cpu",
+    "rustfs-checksums/hotpath-cpu",
+    "rustfs-common/hotpath-cpu",
+    "rustfs-concurrency/hotpath-cpu",
+    "rustfs-config/hotpath-cpu",
+    "rustfs-credentials/hotpath-cpu",
+    "rustfs-data-usage/hotpath-cpu",
+    "rustfs-filemeta/hotpath-cpu",
+    "rustfs-io-metrics/hotpath-cpu",
+    "rustfs-lifecycle/hotpath-cpu",
+    "rustfs-lock/hotpath-cpu",
+    "rustfs-madmin/hotpath-cpu",
+    "rustfs-object-capacity/hotpath-cpu",
+    "rustfs-policy/hotpath-cpu",
+    "rustfs-protos/hotpath-cpu",
+    "rustfs-replication/hotpath-cpu",
+    "rustfs-rio/hotpath-cpu",
+    "rustfs-rio-v2?/hotpath-cpu",
+    "rustfs-s3-types/hotpath-cpu",
+    "rustfs-signer/hotpath-cpu",
+    "rustfs-storage-api/hotpath-cpu",
+    "rustfs-tls-runtime/hotpath-cpu",
+    "rustfs-utils/hotpath-cpu",
+    "rustfs-crypto/hotpath-cpu",
+]
 # Exposes shared lifecycle/tier test utilities (MockWarmBackend, fault
 # injection, xl.meta transition assertions) via `api::tier::test_util`.
 # Enable only from `[dev-dependencies]` (rustfs/backlog#1148 ilm-6).
 test-util = []

 [dependencies]
-hotpath = { workspace = true, optional = true }
+hotpath.workspace = true
 rustfs-filemeta.workspace = true
 rustfs-utils = { workspace = true, features = ["full"] }
 rustfs-rio.workspace = true
@@ -57,7 +141,6 @@ rustfs-policy.workspace = true
 rustfs-protos.workspace = true
 rustfs-replication.workspace = true
 rustfs-lifecycle.workspace = true
-rustfs-kms.workspace = true
 rustfs-s3-types = { workspace = true }
 rustfs-data-usage.workspace = true
 rustfs-object-capacity.workspace = true
@@ -105,6 +188,7 @@ tempfile.workspace = true
 hyper = { workspace = true, features = ["http2", "http1", "server"] }
 hyper-util = { workspace = true, features = ["tokio", "server-auto", "server-graceful", "tracing"] }
 hyper-rustls = { workspace = true, default-features = false, features = ["native-tokio", "http1", "tls12", "logging", "http2", "aws-lc-rs"] }
+hostname.workspace = true
 rustls = { workspace = true, default-features = false, features = ["aws-lc-rs", "logging", "tls12", "prefer-post-quantum", "std"] }
 rustls-pki-types.workspace = true
 tokio = { workspace = true, features = ["io-util", "sync", "signal", "fs", "rt-multi-thread"] }
@@ -124,8 +208,6 @@ libc.workspace = true
 rustix = { workspace = true, features = ["process", "fs"] }
 rustfs-madmin.workspace = true
 reqwest = { workspace = true }
-aes-gcm = { workspace = true, features = ["rand_core"] }
-chacha20poly1305.workspace = true
 aws-sdk-s3 = { workspace = true, default-features = false, features = ["sigv4a", "default-https-client", "rt-tokio"] }
 urlencoding = { workspace = true }
 smallvec = { workspace = true, features = ["serde"] }
@@ -172,6 +172,11 @@ pub mod bucket {
    }

    pub mod replication {
+        pub use crate::bucket::replication::replication_pool::{
+            DurableMrfBacklogSummary, DurableMrfBucketBacklog, DurableMrfTargetBacklog, MrfBacklogObservabilitySummary,
+            MrfBucketBacklogObservability, durable_mrf_backlog_summary_snapshot, durable_mrf_target_backlog_snapshot,
+            mrf_backlog_observability_snapshot,
+        };
        pub use crate::bucket::replication::{
            BucketReplicationResyncStatus, BucketStats, DeletedObjectReplicationInfo, DurableMrfBacklog, DynReplicationPool,
            MrfOpKind, MrfReplicateEntry, MustReplicateOptions, ObjectOpts, REPLICATE_INCOMING_DELETE, ReplicateDecision,
@@ -179,13 +184,13 @@ pub mod bucket {
            ReplicationDeleteStateSource, ReplicationHealQueueResult, ReplicationObjectBridge, ReplicationObjectIO,
            ReplicationOperation, ReplicationPoolTrait, ReplicationPriority, ReplicationQueueAdmission, ReplicationScannerBridge,
            ReplicationState, ReplicationStats, ReplicationStatusType, ReplicationStorage, ReplicationTargetValidationError,
-            ReplicationType, ResyncOpts, ResyncStatusType, TargetReplicationResyncStatus, VersionPurgeStatusType,
-            delete_replication_state_from_config, delete_replication_version_id, get_global_replication_pool,
-            get_global_replication_stats, init_background_replication, read_durable_mrf_backlog, replication_state_to_filemeta,
-            replication_status_to_filemeta, replication_statuses_map, replication_target_arns, resync_start_conflict_id,
-            should_remove_replication_target, should_schedule_delete_replication, should_use_existing_delete_replication_info,
-            should_use_existing_delete_replication_source, validate_replication_config_target_arns,
-            version_purge_status_to_filemeta,
+            ReplicationType, ResyncOpts, ResyncStatusType, RuntimeReplicationTargetBacklog, TargetReplicationResyncStatus,
+            VersionPurgeStatusType, delete_replication_state_from_config, delete_replication_version_id,
+            get_global_replication_pool, get_global_replication_stats, init_background_replication, read_durable_mrf_backlog,
+            replication_state_to_filemeta, replication_status_to_filemeta, replication_statuses_map, replication_target_arns,
+            resync_start_conflict_id, should_remove_replication_target, should_schedule_delete_replication,
+            should_use_existing_delete_replication_info, should_use_existing_delete_replication_source,
+            unsupported_replication_config_field, validate_replication_config_target_arns, version_purge_status_to_filemeta,
        };
    }

@@ -267,12 +272,13 @@ pub mod config {
    pub mod com {
        pub use crate::config::com::{
            COMMA_SEPARATED_LISTS, CONFIG_PREFIX, ENV_CONFIG_RECOVER_ON_CORRUPTION, STORAGE_CLASS_SUB_SYS,
-            ServerConfigCorruptError, ServerConfigSnapshot, delete_config, is_server_config_corrupt_error, lookup_configs,
-            read_config, read_config_no_lock, read_config_with_metadata, read_config_without_migrate,
-            read_config_without_migrate_no_lock, read_existing_server_config_no_lock, read_server_config_snapshot, save_config,
-            save_config_no_lock, save_config_with_opts, save_server_config, save_server_config_no_lock,
-            save_server_config_snapshot, server_config_path, try_migrate_server_config, with_config_object_read_lock,
-            with_config_object_write_lock, with_server_config_read_lock, with_server_config_write_lock,
+            ServerConfigCorruptError, ServerConfigSaveResult, ServerConfigSnapshot, delete_config,
+            is_server_config_corrupt_error, lookup_configs, read_config, read_config_no_lock, read_config_with_metadata,
+            read_config_without_migrate, read_config_without_migrate_no_lock, read_existing_server_config_no_lock,
+            read_server_config_snapshot, save_config, save_config_no_lock, save_config_with_opts, save_server_config,
+            save_server_config_no_lock, save_server_config_snapshot, save_server_config_snapshot_with_generation,
+            server_config_path, try_migrate_server_config, with_config_object_read_lock, with_config_object_write_lock,
+            with_server_config_read_lock, with_server_config_write_lock,
        };
    }

@@ -391,10 +397,12 @@ pub mod notification {

 pub mod object {
    pub use crate::object_api::{
-        BLOCK_SIZE_V2, ERASURE_ALGORITHM, GetObjectBodyCacheHook, GetObjectBodyCacheHookLookup, GetObjectBodySource,
-        GetObjectReader, ObjectInfo, ObjectMutationHook, ObjectOptions, PutObjReader, RangedDecompressReader, StreamConsumer,
-        get_object_body_cache_plaintext_len, lookup_get_object_body_cache_hook, register_get_object_body_cache_hook,
-        register_object_mutation_hook, unregister_get_object_body_cache_hook, unregister_object_mutation_hook,
+        BLOCK_SIZE_V2, ERASURE_ALGORITHM, EncryptionResolutionError, EncryptionResolutionErrorKind, GetObjectBodyCacheHook,
+        GetObjectBodyCacheHookLookup, GetObjectBodySource, GetObjectReader, ObjectEncryptionResolver, ObjectInfo,
+        ObjectMutationHook, ObjectOptions, PutObjReader, RangedDecompressReader, ReadEncryptionMaterial, ReadEncryptionMode,
+        ReadEncryptionRequest, StreamConsumer, get_object_body_cache_plaintext_len, lookup_get_object_body_cache_hook,
+        register_get_object_body_cache_hook, register_object_mutation_hook, unregister_get_object_body_cache_hook,
+        unregister_object_mutation_hook,
    };
    pub use crate::store::PreparedGetObjectReader;
 }
@@ -416,15 +424,15 @@ pub mod rio {

 pub mod rpc {
    pub use crate::cluster::rpc::{
-        AuthenticatedChannel, LocalPeerS3Client, PEER_RESTDRY_RUN, PEER_RESTSIGNAL, PEER_RESTSUB_SYS, PeerRestClient,
-        PeerS3Client, S3PeerSys, SERVICE_SIGNAL_REFRESH_CONFIG, SERVICE_SIGNAL_RELOAD_DYNAMIC, ScannerBucketListing,
-        ScannerPeerActivity, TONIC_RPC_PREFIX, TonicInterceptor, gen_signature_headers, gen_tonic_replay_scope_headers,
-        gen_tonic_signature_headers, gen_tonic_signature_interceptor, node_service_time_out_client,
-        node_service_time_out_client_no_auth, normalize_tonic_rpc_audience, set_tonic_canonical_body_digest,
-        sign_ns_scanner_capability, sign_tonic_rpc_response_proof, tonic_boot_epoch_challenge, tonic_boot_epoch_response_headers,
-        verify_rpc_signature, verify_tonic_boot_epoch_response, verify_tonic_canonical_body_digest,
-        verify_tonic_mutation_body_digest, verify_tonic_rpc_response_proof, verify_tonic_rpc_signature,
-        verify_tonic_rpc_signature_with_bootstrap,
+        AuthenticatedChannel, KMS_SIGNAL_SUBSYSTEM, LocalPeerS3Client, PEER_RESTDRY_RUN, PEER_RESTSIGNAL, PEER_RESTSUB_SYS,
+        PeerRestClient, PeerS3Client, S3PeerSys, SERVICE_SIGNAL_REFRESH_CONFIG, SERVICE_SIGNAL_RELOAD_DYNAMIC,
+        ScannerBucketListing, ScannerPeerActivity, TONIC_RPC_PREFIX, TonicInterceptor, gen_signature_headers,
+        gen_tonic_replay_scope_headers, gen_tonic_signature_headers, gen_tonic_signature_interceptor,
+        node_service_time_out_client, node_service_time_out_client_no_auth, normalize_tonic_rpc_audience,
+        set_tonic_canonical_body_digest, sign_ns_scanner_capability, sign_tonic_rpc_response_proof, tonic_boot_epoch_challenge,
+        tonic_boot_epoch_response_headers, verify_rpc_signature, verify_tonic_boot_epoch_response,
+        verify_tonic_canonical_body_digest, verify_tonic_mutation_body_digest, verify_tonic_rpc_response_proof,
+        verify_tonic_rpc_signature, verify_tonic_rpc_signature_with_bootstrap,
    };
 }

@@ -579,8 +579,26 @@ pub struct BucketMetadataSys {
    /// Serializes metadata-map commits and their derived cache updates for one
    /// bucket. Namespace locks, when present, are acquired before this lock.
    metadata_publish_locks: Arc<MetadataPublishLockRegistry>,
+    /// Deduplicates concurrent lazy loads of one bucket's metadata, so N
+    /// simultaneous cache misses issue a single disk read instead of N.
+    ///
+    /// This is the `singleflight` that upstream applies to its own lazy
+    /// `GetConfig`. Without it the namespace *read* lock the load holds is no
+    /// help: read locks are shared, so it excludes concurrent config writers
+    /// but not concurrent readers, and every caller still pays a full
+    /// erasure-set metadata fanout. A separate registry from
+    /// `metadata_publish_locks`, reusing the same per-bucket lock machinery.
+    ///
+    /// Lock order: this lock, then the namespace lock, then the publish lock,
+    /// then the metadata map. It is only ever taken as the first of those, so
+    /// it cannot invert against a path that already holds one of the others.
+    lazy_load_locks: Arc<MetadataPublishLockRegistry>,
    #[cfg(test)]
    lazy_load_lock_probe: std::sync::atomic::AtomicBool,
+    /// Counts disk loads taken by the lazy `get_config` path, so a test can
+    /// prove concurrent misses collapse into one.
+    #[cfg(test)]
+    lazy_disk_loads: std::sync::atomic::AtomicUsize,
    /// Buckets recently observed to have no persisted metadata. Serving the
    /// fabricated default from here (instead of re-reading disk) keeps the
    /// per-request cost of repeated lookups for such names bounded — without
@@ -599,8 +617,13 @@ impl BucketMetadataSys {
            metadata_publish_locks: Arc::new(MetadataPublishLockRegistry {
                locks: StdMutex::new(HashMap::new()),
            }),
+            lazy_load_locks: Arc::new(MetadataPublishLockRegistry {
+                locks: StdMutex::new(HashMap::new()),
+            }),
            #[cfg(test)]
            lazy_load_lock_probe: std::sync::atomic::AtomicBool::new(false),
+            #[cfg(test)]
+            lazy_disk_loads: std::sync::atomic::AtomicUsize::new(0),
            absent_metadata: moka::future::Cache::builder()
                .max_capacity(ABSENT_BUCKET_METADATA_MAX_ENTRIES)
                .time_to_live(ABSENT_BUCKET_METADATA_TTL)
@@ -615,16 +638,22 @@ impl BucketMetadataSys {
    }

    fn metadata_publish_lock(&self, bucket: &str) -> Arc<Mutex<MetadataPublishLockState>> {
-        let mut locks = self
-            .metadata_publish_locks
-            .locks
-            .lock()
-            .unwrap_or_else(|poisoned| poisoned.into_inner());
+        Self::bucket_lock_in(&self.metadata_publish_locks, bucket)
+    }
+
+    /// Per-bucket gate for the lazy `get_config` disk load. See
+    /// [`Self::lazy_load_locks`].
+    fn lazy_load_lock(&self, bucket: &str) -> Arc<Mutex<MetadataPublishLockState>> {
+        Self::bucket_lock_in(&self.lazy_load_locks, bucket)
+    }
+
+    fn bucket_lock_in(registry: &Arc<MetadataPublishLockRegistry>, bucket: &str) -> Arc<Mutex<MetadataPublishLockState>> {
+        let mut locks = registry.locks.lock().unwrap_or_else(|poisoned| poisoned.into_inner());
        locks.get(bucket).and_then(Weak::upgrade).unwrap_or_else(|| {
            let lock = Arc::new_cyclic(|lock| {
                Mutex::new(MetadataPublishLockState {
                    bucket: bucket.to_string(),
-                    registry: Arc::downgrade(&self.metadata_publish_locks),
+                    registry: Arc::downgrade(registry),
                    lock: lock.clone(),
                })
            });
@@ -1079,6 +1108,27 @@ impl BucketMetadataSys {
                return Ok((Arc::new(bm), true));
            }

+            // Collapse concurrent misses for this bucket into one disk load.
+            // Taken before the namespace lock — see `lazy_load_locks` for the
+            // ordering rule.
+            let load_lock = self.lazy_load_lock(bucket);
+            let _load_guard = load_lock.lock_owned().await;
+
+            // Re-check both caches: whoever held the gate before us may have
+            // already answered this exact question, and repeating the fanout
+            // is the whole cost this gate exists to avoid.
+            if let Some(bm) = self.metadata_map.read().await.get(bucket).cloned() {
+                return Ok((bm, true));
+            }
+            if self.absent_metadata.get(bucket).await.is_some() {
+                let mut bm = BucketMetadata::new(bucket);
+                bm.default_timestamps();
+                return Ok((Arc::new(bm), true));
+            }
+
+            #[cfg(test)]
+            self.lazy_disk_loads.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+
            let lock = self.api.new_ns_lock(bucket, bucket).await?;
            let guard = lock.get_read_lock(crate::set_disk::get_lock_acquire_timeout()).await?;
            #[cfg(test)]
@@ -1431,6 +1481,43 @@ mod tests {
    use serial_test::serial;
    use tokio::time::timeout;

+    /// Concurrent cache misses for one bucket must collapse into a single disk
+    /// load.
+    ///
+    /// The namespace read lock the lazy path already holds does not provide
+    /// this: read locks are shared, so it excludes concurrent config writers
+    /// but not concurrent readers. Without the dedup gate every caller pays its
+    /// own namespace-lock acquisition plus a full erasure-set metadata fanout —
+    /// and the paths that reach `get_config` are per-request, so the multiplier
+    /// is request concurrency.
+    #[tokio::test]
+    async fn concurrent_lazy_loads_of_one_bucket_issue_a_single_disk_read() {
+        use std::sync::atomic::Ordering;
+
+        let (_dirs, ecstore) = isolated_store_over_temp_disks().await;
+        let sys = Arc::new(BucketMetadataSys::new(ecstore));
+
+        // A name with no persisted metadata: every caller misses the map, and
+        // the absent-cache entry does not exist until the first load records it.
+        let bucket = "singleflight-bucket";
+        let waiters = 8;
+
+        let results = futures::future::join_all((0..waiters).map(|_| {
+            let sys = Arc::clone(&sys);
+            async move { sys.get_config(bucket).await.map(|(bm, _)| bm.name.clone()) }
+        }))
+        .await;
+
+        for result in results {
+            assert_eq!(result.expect("every caller must get an answer"), bucket);
+        }
+        assert_eq!(
+            sys.lazy_disk_loads.load(Ordering::Relaxed),
+            1,
+            "concurrent misses for one bucket must share a single disk load"
+        );
+    }
+
    /// Pins the fail-closed caching contract of the lazy `get_config` path
    /// and the refresh no-replace rule: fabricated defaults are returned but
    /// never served by the map-only `get()`, persisted metadata is cached on
@@ -46,7 +46,7 @@ mod runtime_boundary;
 pub use datatypes::ResyncStatusType;
 pub use replication_config_boundary::{
    ObjectOpts, ReplicationConfigurationExt, ReplicationTargetValidationError, replication_target_arns,
-    should_remove_replication_target, validate_replication_config_target_arns,
+    should_remove_replication_target, unsupported_replication_config_field, validate_replication_config_target_arns,
 };
 #[cfg(test)]
 pub(crate) use replication_filemeta_boundary::ReplicateTargetDecision;
@@ -78,7 +78,7 @@ pub use replication_queue_boundary::{
 };
 pub use replication_resync_boundary::{BucketReplicationResyncStatus, ResyncOpts, TargetReplicationResyncStatus};
 pub use replication_scanner_bridge::ReplicationScannerBridge;
-pub use replication_state::ReplicationStats;
+pub use replication_state::{ReplicationStats, RuntimeReplicationTargetBacklog};
 pub use replication_stats_boundary::BucketStats;
 pub use replication_storage_boundary::{ReplicationObjectIO, ReplicationStorage};
 pub(crate) use replication_target_config_bridge::ReplicationTargetConfigBridge;
@@ -14,5 +14,5 @@

 pub use rustfs_replication::{
    ObjectOpts, ReplicationConfigurationExt, ReplicationTargetValidationError, replication_target_arns,
-    should_remove_replication_target, validate_replication_config_target_arns,
+    should_remove_replication_target, unsupported_replication_config_field, validate_replication_config_target_arns,
 };
@@ -14,8 +14,11 @@

 use std::{collections::HashMap, sync::Arc};

+use super::replication_error_boundary::Result;
 use super::replication_filemeta_boundary::{ReplicateDecision, ReplicationStatusType, ReplicationType};
-use super::replication_object_config::{check_replicate_delete, get_must_replicate_options, must_replicate};
+use super::replication_object_config::{
+    check_replicate_delete, check_replicate_delete_strict, get_must_replicate_options, must_replicate,
+};
 use super::replication_object_decision_boundary::MustReplicateOptions;
 use super::replication_pool::{schedule_replication, schedule_replication_delete};
 use super::replication_queue_boundary::DeletedObjectReplicationInfo;
@@ -50,6 +53,16 @@ impl ReplicationObjectBridge {
        check_replicate_delete(bucket, object, source, opts, get_error).await
    }

+    pub async fn check_delete_strict(
+        bucket: &str,
+        object: &ObjectToDelete,
+        source: &ObjectInfo,
+        opts: &ObjectOptions,
+        get_error: Option<String>,
+    ) -> Result<ReplicateDecision> {
+        check_replicate_delete_strict(bucket, object, source, opts, get_error).await
+    }
+
    pub async fn schedule_object<S: ReplicationStorage>(
        object: ObjectInfo,
        storage: Arc<S>,
@@ -169,9 +169,8 @@ pub(crate) async fn check_replicate_delete(
    del_opts: &ObjectOptions,
    gerr: Option<String>,
 ) -> ReplicateDecision {
-    let rcfg = match get_replication_config(bucket).await {
-        Ok(Some(config)) => config,
-        Ok(None) => return ReplicateDecision::default(),
+    match check_replicate_delete_strict(bucket, dobj, oi, del_opts, gerr).await {
+        Ok(decision) => decision,
        Err(err) => {
            error!(
                event = EVENT_RESYNC_CONFIG_LOOKUP_SKIPPED,
@@ -182,16 +181,30 @@ pub(crate) async fn check_replicate_delete(
                error = %err,
                "Failed to look up replication config for delete replication"
            );
-            return ReplicateDecision::default();
+            ReplicateDecision::default()
        }
+    }
+}
+
+pub(crate) async fn check_replicate_delete_strict(
+    bucket: &str,
+    dobj: &ObjectToDelete,
+    oi: &ObjectInfo,
+    del_opts: &ObjectOptions,
+    gerr: Option<String>,
+) -> Result<ReplicateDecision> {
+    let rcfg = match get_replication_config(bucket).await {
+        Ok(Some(config)) => config,
+        Ok(None) => return Ok(ReplicateDecision::default()),
+        Err(err) => return Err(err),
    };

    if del_opts.replication_request {
-        return ReplicateDecision::default();
+        return Ok(ReplicateDecision::default());
    }

-    if !del_opts.versioned {
-        return ReplicateDecision::default();
+    if !del_opts.versioned && !del_opts.version_suspended {
+        return Ok(ReplicateDecision::default());
    }

    let replication_delete = object_to_delete_for_replication(dobj);
@@ -209,7 +222,7 @@ pub(crate) async fn check_replicate_delete(
    let mut dsc = ReplicateDecision::new();

    if tgt_arns.is_empty() {
-        return dsc;
+        return Ok(dsc);
    }

    for tgt_arn in tgt_arns {
@@ -239,7 +252,7 @@ pub(crate) async fn check_replicate_delete(
        dsc.set(tgt_dsc);
    }

-    dsc
+    Ok(dsc)
 }

 pub(crate) async fn must_replicate(bucket: &str, object: &str, mopts: MustReplicateOptions) -> ReplicateDecision {
@@ -1151,60 +1151,6 @@ pub async fn replicate_delete<S: ReplicationStorage>(dobj: DeletedObjectReplicat
        dobj.delete_object.version_id
    };

-    let _rcfg = match get_replication_config(&bucket).await {
-        Ok(Some(config)) => config,
-        Ok(None) => {
-            debug!(
-                event = EVENT_REPLICATION_DELETE_SKIPPED,
-                component = LOG_COMPONENT_ECSTORE,
-                subsystem = LOG_SUBSYSTEM_REPLICATION_RESYNC,
-                bucket = %bucket,
-                reason = "replication_config_missing",
-                "Skipping replication delete because replication config is missing"
-            );
-            send_local_event(EventArgs {
-                event_name: EventName::ObjectReplicationNotTracked.to_string(),
-                bucket_name: bucket.clone(),
-                object: ObjectInfo {
-                    bucket: bucket.clone(),
-                    name: dobj.delete_object.object_name.clone(),
-                    version_id,
-                    delete_marker: dobj.delete_object.delete_marker,
-                    ..Default::default()
-                },
-                user_agent: "Internal: [Replication]".to_string(),
-                ..Default::default()
-            });
-
-            return;
-        }
-        Err(err) => {
-            debug!(
-                event = EVENT_REPLICATION_DELETE_SKIPPED,
-                component = LOG_COMPONENT_ECSTORE,
-                subsystem = LOG_SUBSYSTEM_REPLICATION_RESYNC,
-                bucket = %bucket,
-                error = %err,
-                reason = "replication_config_lookup_failed",
-                "Skipping replication delete because replication config lookup failed"
-            );
-            send_local_event(EventArgs {
-                event_name: EventName::ObjectReplicationNotTracked.to_string(),
-                bucket_name: bucket.clone(),
-                object: ObjectInfo {
-                    bucket: bucket.clone(),
-                    name: dobj.delete_object.object_name.clone(),
-                    version_id,
-                    delete_marker: dobj.delete_object.delete_marker,
-                    ..Default::default()
-                },
-                user_agent: "Internal: [Replication]".to_string(),
-                ..Default::default()
-            });
-            return;
-        }
-    };
-
    if dobj.delete_object.delete_marker
        && let Some(delete_marker_version_id) = dobj.delete_object.delete_marker_version_id
    {
@@ -22,9 +22,9 @@ use super::replication_stats_boundary::{
    QueueCache, ReplicationMetricScope, SRMetricsSummary, XferStats,
 };
 use super::runtime_boundary as runtime_sources;
-use std::collections::HashMap;
-use std::sync::Arc;
+use std::collections::{HashMap, hash_map::Entry};
 use std::sync::atomic::{AtomicI64, Ordering};
+use std::sync::{Arc, LazyLock, Mutex as StdMutex, Weak};
 use std::time::{Duration, SystemTime};
 use tokio::sync::{Mutex, RwLock};
 use tokio::time::interval;
@@ -143,7 +143,7 @@ pub struct ReplicationStats {
    // Active worker statistics
    pub workers: Arc<Mutex<ActiveWorkerStat>>,
    // Queue statistics cache
-    pub q_cache: Arc<Mutex<QueueCache>>,
+    pub q_cache: Arc<StdMutex<QueueCache>>,
    // Proxy statistics cache
    pub p_cache: Arc<Mutex<ProxyStatsCache>>,
    // MRF backlog statistics (simplified)
@@ -153,12 +153,89 @@ pub struct ReplicationStats {
    pub most_recent_stats: Arc<Mutex<HashMap<String, BucketStats>>>,
 }

+#[derive(Debug, Clone, Default, PartialEq, Eq)]
+pub struct RuntimeReplicationTargetBacklog {
+    pub bucket: String,
+    pub target_arn: String,
+    pub count: u64,
+    pub bytes: u64,
+}
+
+type TargetQueueKey = (String, String);
+type TargetQueueCache = HashMap<TargetQueueKey, InQueueMetric>;
+
+struct TargetQueueCacheSlot {
+    owner: Weak<StdMutex<QueueCache>>,
+    metrics: TargetQueueCache,
+}
+
+impl TargetQueueCacheSlot {
+    fn new(owner: &Arc<StdMutex<QueueCache>>) -> Self {
+        Self {
+            owner: Arc::downgrade(owner),
+            metrics: TargetQueueCache::default(),
+        }
+    }
+
+    fn belongs_to(&self, owner: &Arc<StdMutex<QueueCache>>) -> bool {
+        self.owner.upgrade().is_some_and(|current| Arc::ptr_eq(&current, owner))
+    }
+}
+
+// Keep runtime target counters outside ReplicationStats to preserve its public struct shape.
+static TARGET_QUEUE_CACHES: LazyLock<StdMutex<Vec<TargetQueueCacheSlot>>> = LazyLock::new(|| StdMutex::new(Vec::new()));
+
+fn i64_to_u64_floor_zero(value: i64) -> u64 {
+    u64::try_from(value.max(0)).unwrap_or(0)
+}
+
+fn normalized_target_arns(target_arns: &[String]) -> Vec<&str> {
+    let mut target_arns = target_arns
+        .iter()
+        .map(String::as_str)
+        .filter(|target_arn| !target_arn.is_empty())
+        .collect::<Vec<_>>();
+    target_arns.sort_unstable();
+    target_arns.dedup();
+    target_arns
+}
+
+fn target_queue_cache_snapshot(cache: &TargetQueueCache) -> Vec<RuntimeReplicationTargetBacklog> {
+    cache
+        .iter()
+        .filter_map(|((bucket, target_arn), metric)| {
+            let count = i64_to_u64_floor_zero(metric.curr.get_current_count());
+            let bytes = i64_to_u64_floor_zero(metric.curr.get_current_bytes());
+            (count > 0 || bytes > 0).then(|| RuntimeReplicationTargetBacklog {
+                bucket: bucket.clone(),
+                target_arn: target_arn.clone(),
+                count,
+                bytes,
+            })
+        })
+        .collect()
+}
+
+fn prune_stale_target_queue_caches(caches: &mut Vec<TargetQueueCacheSlot>) {
+    caches.retain(|slot| slot.owner.strong_count() > 0);
+}
+
+fn with_target_queue_caches<T>(f: impl FnOnce(&mut Vec<TargetQueueCacheSlot>) -> T) -> T {
+    match TARGET_QUEUE_CACHES.lock() {
+        Ok(mut caches) => f(&mut caches),
+        Err(poisoned) => {
+            let mut caches = poisoned.into_inner();
+            f(&mut caches)
+        }
+    }
+}
+
 impl ReplicationStats {
    pub fn new() -> Self {
        Self {
            sr_stats: Arc::new(SRStats::new()),
            workers: Arc::new(Mutex::new(ActiveWorkerStat::new())),
-            q_cache: Arc::new(Mutex::new(QueueCache::new())),
+            q_cache: Arc::new(StdMutex::new(QueueCache::new())),
            p_cache: Arc::new(Mutex::new(ProxyStatsCache::new())),
            mrf_stats: HashMap::new(),
            cache: Arc::new(RwLock::new(HashMap::new())),
@@ -198,8 +275,9 @@ impl ReplicationStats {
            let mut interval = interval(Duration::from_secs(2));
            loop {
                interval.tick().await;
-                let mut cache = q_cache_clone.lock().await;
-                cache.update();
+                if let Ok(mut cache) = q_cache_clone.lock() {
+                    cache.update();
+                }
            }
        });
    }
@@ -391,12 +469,13 @@ impl ReplicationStats {
        drop(cache);

        {
-            let q_cache = self.q_cache.lock().await;
-            for (bucket, queue_stats) in &q_cache.bucket_stats {
-                let bucket_stats = result.entry(bucket.clone()).or_insert_with(BucketReplicationStats::new);
-                bucket_stats.q_stat = queue_stats.snapshot();
-                bucket_stats.mark_node_local_provider_available();
-                bucket_stats.queue_scope = ReplicationMetricScope::NodeLocal;
+            if let Ok(q_cache) = self.q_cache.lock() {
+                for (bucket, queue_stats) in &q_cache.bucket_stats {
+                    let bucket_stats = result.entry(bucket.clone()).or_insert_with(BucketReplicationStats::new);
+                    bucket_stats.q_stat = queue_stats.snapshot();
+                    bucket_stats.mark_node_local_provider_available();
+                    bucket_stats.queue_scope = ReplicationMetricScope::NodeLocal;
+                }
            }
        }

@@ -429,8 +508,11 @@ impl ReplicationStats {
        let boot_time = SystemTime::UNIX_EPOCH; // simplified implementation
        let uptime = SystemTime::now().duration_since(boot_time).unwrap_or_default().as_secs() as i64;

-        let q_cache = self.q_cache.lock().await;
-        let queued = q_cache.get_site_stats();
+        let queued = self
+            .q_cache
+            .lock()
+            .map(|q_cache| q_cache.get_site_stats())
+            .unwrap_or_default();

        let p_cache = self.p_cache.lock().await;
        let proxied = p_cache.get_site_stats();
@@ -633,8 +715,9 @@ impl ReplicationStats {
        drop(cache);

        {
-            let q_cache = self.q_cache.lock().await;
-            if let Some(queue_stats) = q_cache.bucket_stats.get(bucket) {
+            if let Ok(q_cache) = self.q_cache.lock()
+                && let Some(queue_stats) = q_cache.bucket_stats.get(bucket)
+            {
                replication_stats.q_stat = queue_stats.snapshot();
            }
        }
@@ -665,31 +748,79 @@ impl ReplicationStats {
    }

    /// Increase queue statistics
-    pub async fn inc_q(&self, bucket: &str, size: i64, _is_delete_repl: bool, _op_type: ReplicationType) {
-        let mut q_cache = self.q_cache.lock().await;
-        let stats = q_cache
-            .bucket_stats
-            .entry(bucket.to_string())
-            .or_insert_with(InQueueMetric::default);
-        stats.curr.now_bytes.fetch_add(size, Ordering::Relaxed);
-        stats.curr.now_count.fetch_add(1, Ordering::Relaxed);
-
-        q_cache.sr_queue_stats.curr.now_bytes.fetch_add(size, Ordering::Relaxed);
-        q_cache.sr_queue_stats.curr.now_count.fetch_add(1, Ordering::Relaxed);
+    pub fn inc_q(&self, bucket: &str, size: i64, _is_delete_repl: bool, _op_type: ReplicationType) {
+        if let Ok(mut q_cache) = self.q_cache.lock() {
+            q_cache.inc(bucket, size);
+        }
    }

    /// Decrease queue statistics
-    pub async fn dec_q(&self, bucket: &str, size: i64, _is_del_marker: bool, _op_type: ReplicationType) {
-        let mut q_cache = self.q_cache.lock().await;
-        let stats = q_cache
-            .bucket_stats
-            .entry(bucket.to_string())
-            .or_insert_with(InQueueMetric::default);
-        stats.curr.now_bytes.fetch_sub(size, Ordering::Relaxed);
-        stats.curr.now_count.fetch_sub(1, Ordering::Relaxed);
+    pub fn dec_q(&self, bucket: &str, size: i64, _is_del_marker: bool, _op_type: ReplicationType) {
+        if let Ok(mut q_cache) = self.q_cache.lock() {
+            q_cache.dec(bucket, size);
+        }
+    }

-        q_cache.sr_queue_stats.curr.now_bytes.fetch_sub(size, Ordering::Relaxed);
-        q_cache.sr_queue_stats.curr.now_count.fetch_sub(1, Ordering::Relaxed);
+    pub(crate) fn inc_target_q(&self, bucket: &str, target_arns: &[String], size: i64) {
+        let target_arns = normalized_target_arns(target_arns);
+        if target_arns.is_empty() {
+            return;
+        }
+        with_target_queue_caches(|caches| {
+            prune_stale_target_queue_caches(caches);
+            let slot_index = match caches.iter().position(|slot| slot.belongs_to(&self.q_cache)) {
+                Some(index) => index,
+                None => {
+                    caches.push(TargetQueueCacheSlot::new(&self.q_cache));
+                    caches.len() - 1
+                }
+            };
+            let slot = &mut caches[slot_index];
+            let bucket = bucket.to_string();
+            for target_arn in target_arns {
+                let metric = match slot.metrics.entry((bucket.clone(), target_arn.to_string())) {
+                    Entry::Occupied(entry) => entry.into_mut(),
+                    Entry::Vacant(entry) => entry.insert(InQueueMetric::default()),
+                };
+                metric.curr.add_current(size, 1);
+            }
+        });
+    }
+
+    pub(crate) fn dec_target_q(&self, bucket: &str, target_arns: &[String], size: i64) {
+        let target_arns = normalized_target_arns(target_arns);
+        if target_arns.is_empty() {
+            return;
+        }
+        with_target_queue_caches(|caches| {
+            prune_stale_target_queue_caches(caches);
+            if let Some(slot) = caches.iter_mut().find(|slot| slot.belongs_to(&self.q_cache)) {
+                let bucket = bucket.to_string();
+                for target_arn in target_arns {
+                    if let Some(metric) = slot.metrics.get_mut(&(bucket.clone(), target_arn.to_string())) {
+                        metric.curr.subtract_current(size, 1);
+                    }
+                }
+                slot.metrics
+                    .retain(|_, metric| metric.curr.get_current_count() > 0 || metric.curr.get_current_bytes() > 0);
+            }
+        });
+    }
+
+    pub fn runtime_target_backlog_snapshot(&self) -> Vec<RuntimeReplicationTargetBacklog> {
+        let mut snapshot = with_target_queue_caches(|caches| {
+            caches
+                .iter()
+                .find(|slot| slot.belongs_to(&self.q_cache))
+                .map(|slot| target_queue_cache_snapshot(&slot.metrics))
+                .unwrap_or_default()
+        });
+        snapshot.sort_by(|left, right| {
+            left.bucket
+                .cmp(&right.bucket)
+                .then_with(|| left.target_arn.cmp(&right.target_arn))
+        });
+        snapshot
    }

    /// Increase proxy metrics
@@ -715,6 +846,94 @@ impl Default for ReplicationStats {
 mod tests {
    use super::*;

+    #[test]
+    fn runtime_target_backlog_snapshot_tracks_targets() {
+        let stats = ReplicationStats::new();
+        stats.inc_target_q(
+            "photos",
+            &[
+                "arn:rustfs:replication:target-b".to_string(),
+                "arn:rustfs:replication:target-a".to_string(),
+                "arn:rustfs:replication:target-a".to_string(),
+            ],
+            1024,
+        );
+
+        let snapshot = stats.runtime_target_backlog_snapshot();
+
+        assert_eq!(
+            snapshot,
+            vec![
+                RuntimeReplicationTargetBacklog {
+                    bucket: "photos".to_string(),
+                    target_arn: "arn:rustfs:replication:target-a".to_string(),
+                    count: 1,
+                    bytes: 1024,
+                },
+                RuntimeReplicationTargetBacklog {
+                    bucket: "photos".to_string(),
+                    target_arn: "arn:rustfs:replication:target-b".to_string(),
+                    count: 1,
+                    bytes: 1024,
+                },
+            ]
+        );
+    }
+
+    #[test]
+    fn runtime_target_backlog_ignores_empty_targets() {
+        let stats = ReplicationStats::new();
+        stats.inc_target_q("photos", &["".to_string()], 1024);
+
+        assert!(stats.runtime_target_backlog_snapshot().is_empty());
+    }
+
+    #[test]
+    fn runtime_target_backlog_is_scoped_to_stats_instance() {
+        let first = ReplicationStats::new();
+        let second = ReplicationStats::new();
+        first.inc_target_q("photos", &["arn:rustfs:replication:target-a".to_string()], 1024);
+
+        assert!(second.runtime_target_backlog_snapshot().is_empty());
+        assert_eq!(first.runtime_target_backlog_snapshot()[0].count, 1);
+    }
+
+    #[test]
+    fn runtime_target_backlog_decrements_with_saturation() {
+        let stats = ReplicationStats::new();
+        let target_arns = ["arn:rustfs:replication:target-a".to_string()];
+        stats.inc_target_q("photos", &target_arns, 1024);
+        stats.dec_target_q("photos", &target_arns, 2048);
+
+        assert!(stats.runtime_target_backlog_snapshot().is_empty());
+    }
+
+    #[test]
+    fn runtime_target_backlog_prunes_stale_sidecar_on_next_access() {
+        {
+            let stats = ReplicationStats::new();
+            stats.inc_target_q("photos", &["arn:rustfs:replication:target-a".to_string()], 1024);
+            assert!(
+                TARGET_QUEUE_CACHES
+                    .lock()
+                    .expect("target queue cache mutex")
+                    .iter()
+                    .any(|slot| slot.owner.strong_count() > 0)
+            );
+        }
+
+        let stats = ReplicationStats::new();
+        stats.inc_target_q("photos", &["arn:rustfs:replication:target-b".to_string()], 1024);
+
+        assert!(
+            TARGET_QUEUE_CACHES
+                .lock()
+                .expect("target queue cache mutex")
+                .iter()
+                .all(|slot| slot.owner.strong_count() > 0)
+        );
+    }
+
    #[tokio::test]
    async fn test_replication_stats_new() {
        let stats = ReplicationStats::new();
@@ -801,14 +1020,14 @@ mod tests {
    async fn latest_stats_include_queue_until_drained() {
        let stats = ReplicationStats::new();

-        stats.inc_q("queued-bucket", 4096, false, ReplicationType::Object).await;
+        stats.inc_q("queued-bucket", 4096, false, ReplicationType::Object);
        let queued = stats.get_latest_replication_stats("queued-bucket").await;
        assert!(queued.replication_stats.provider_available);
        assert_eq!(queued.replication_stats.q_stat.curr.count, 1);
        assert_eq!(queued.replication_stats.q_stat.curr.bytes, 4096);
        assert_eq!(queued.replication_stats.queue_scope, ReplicationMetricScope::NodeLocal);

-        stats.dec_q("queued-bucket", 4096, false, ReplicationType::Object).await;
+        stats.dec_q("queued-bucket", 4096, false, ReplicationType::Object);
        let drained = stats.get_latest_replication_stats("queued-bucket").await;
        assert_eq!(drained.replication_stats.q_stat.curr.count, 0);
        assert_eq!(drained.replication_stats.q_stat.curr.bytes, 0);
@@ -911,7 +1130,7 @@ mod tests {
        for _ in 0..32 {
            let stats = Arc::clone(&stats);
            tasks.push(tokio::spawn(async move {
-                stats.inc_q("concurrent-bucket", 7, false, ReplicationType::Object).await;
+                stats.inc_q("concurrent-bucket", 7, false, ReplicationType::Object);
            }));
        }
        for task in tasks {
@@ -46,16 +46,6 @@ lazy_static! {
        m.insert("x-amz-replication-status".to_string(), true);
        m
    };
-    static ref SSE_HEADERS: HashMap<String, bool> = {
-        let mut m = HashMap::new();
-        m.insert("x-amz-server-side-encryption".to_string(), true);
-        m.insert("x-amz-server-side-encryption-aws-kms-key-id".to_string(), true);
-        m.insert("x-amz-server-side-encryption-context".to_string(), true);
-        m.insert("x-amz-server-side-encryption-customer-algorithm".to_string(), true);
-        m.insert("x-amz-server-side-encryption-customer-key".to_string(), true);
-        m.insert("x-amz-server-side-encryption-customer-key-md5".to_string(), true);
-        m
-    };
 }

 pub fn is_standard_query_value(qs_key: &str) -> bool {
@@ -70,16 +60,12 @@ pub fn is_standard_header(header_key: &str) -> bool {
    *SUPPORTED_HEADERS.get(&header_key.to_lowercase()).unwrap_or(&false)
 }

-pub fn is_sse_header(header_key: &str) -> bool {
-    *SSE_HEADERS.get(&header_key.to_lowercase()).unwrap_or(&false)
-}
-
 pub fn is_amz_header(header_key: &str) -> bool {
    let key = header_key.to_lowercase();
    key.starts_with("x-amz-meta-")
        || key.starts_with("x-amz-grant-")
        || key == "x-amz-acl"
-        || is_sse_header(header_key)
+        || rustfs_utils::http::is_sse_header(header_key)
        || key.starts_with("x-amz-checksum-")
 }

@@ -44,7 +44,7 @@ pub(crate) use internode_data_transport::TcpHttpInternodeDataTransport;
 pub use internode_data_transport::build_internode_data_transport_from_env;
 pub(crate) use peer_rest_client::TierConfigReloadOutcome;
 pub use peer_rest_client::{
-    PEER_RESTDRY_RUN, PEER_RESTSIGNAL, PEER_RESTSUB_SYS, PeerRestClient, SERVICE_SIGNAL_REFRESH_CONFIG,
+    KMS_SIGNAL_SUBSYSTEM, PEER_RESTDRY_RUN, PEER_RESTSIGNAL, PEER_RESTSUB_SYS, PeerRestClient, SERVICE_SIGNAL_REFRESH_CONFIG,
    SERVICE_SIGNAL_RELOAD_DYNAMIC, ScannerPeerActivity,
 };
 pub(crate) use peer_s3_client::heal_bucket_local_on_disks;
@@ -45,9 +45,9 @@ use rustfs_protos::proto_gen::node_service::{
    HealControlRequest, LoadBucketMetadataRequest, LoadGroupRequest, LoadPolicyMappingRequest, LoadPolicyRequest,
    LoadRebalanceMetaRequest, LoadServiceAccountRequest, LoadTransitionTierConfigRequest, LoadUserRequest,
    LocalStorageInfoRequest, Mss, ReloadPoolMetaRequest, ReloadSiteReplicationConfigRequest, ScannerActivityRequest,
-    ScannerActivityResponse, ServerInfoRequest, SignalServiceRequest, StartDecommissionRequest, StartProfilingRequest,
-    StopRebalanceRequest, TierMutationAbortRequest, TierMutationCommitRequest, TierMutationControlResponse,
-    TierMutationPeerState, TierMutationPrepareRequest, node_service_client::NodeServiceClient,
+    ScannerActivityResponse, ServerInfoRequest, SignalServiceRequest, SignalServiceResponse, StartDecommissionRequest,
+    StartProfilingRequest, StopRebalanceRequest, TierMutationAbortRequest, TierMutationCommitRequest,
+    TierMutationControlResponse, TierMutationPeerState, TierMutationPrepareRequest, node_service_client::NodeServiceClient,
    tier_mutation_control_service_client::TierMutationControlServiceClient,
 };
 pub use rustfs_protos::{PEER_RESTDRY_RUN, PEER_RESTSIGNAL, PEER_RESTSUB_SYS};
@@ -58,7 +58,7 @@ use std::{
    collections::HashMap,
    io::Cursor,
    sync::{
-        Arc,
+        Arc, Weak,
        atomic::{AtomicBool, Ordering},
    },
    time::SystemTime,
@@ -71,6 +71,12 @@ use uuid::Uuid;

 pub const SERVICE_SIGNAL_REFRESH_CONFIG: u64 = 1;
 pub const SERVICE_SIGNAL_RELOAD_DYNAMIC: u64 = 2;
+/// Dynamic config subsystem for the cluster-persisted KMS configuration.
+///
+/// KMS configuration lives in its own cluster object rather than in the server
+/// config document, so it is not a `ServerConfig` subsystem; it only shares the
+/// reload signal transport.
+pub const KMS_SIGNAL_SUBSYSTEM: &str = "kms";
 const BACKGROUND_HEAL_STATUS_MAX_MESSAGE_SIZE: usize = 64 * 1024;
 const HEAL_CONTROL_FINGERPRINT_MAX_SIZE: usize = 256;
 const HEAL_CONTROL_PAYLOAD_MAX_SIZE: usize = 64 * 1024;
@@ -99,8 +105,13 @@ fn decode_bucket_stats_response(response: GetBucketStatsDataResponse) -> Result<
 }

 fn validate_signal_service_protocol(sig: u64, sub_sys: &str, protocol_version: u32) -> Result<()> {
+    // The version stays pinned to DYNAMIC_CONFIG_PROTOCOL_VERSION rather than
+    // being bumped per subsystem: the comparison is shared, so raising it would
+    // retire peers that already converge scanner and heal config correctly.
+    // Subsystems added after a peer was built are rejected by that peer's own
+    // subsystem allow-list, which surfaces as an explicit failed signal.
    if sig == SERVICE_SIGNAL_RELOAD_DYNAMIC
-        && matches!(sub_sys, SCANNER_SUB_SYS | HEAL_SUB_SYS)
+        && matches!(sub_sys, SCANNER_SUB_SYS | HEAL_SUB_SYS | KMS_SIGNAL_SUBSYSTEM)
        && protocol_version < rustfs_protos::DYNAMIC_CONFIG_PROTOCOL_VERSION
    {
        return Err(Error::other(format!("peer does not support dynamic {sub_sys} config convergence")));
@@ -350,6 +361,44 @@ impl PeerRestClient {
        }
    }

+    fn parse_topology_host(peer_host_port: &str, grid_host: &str) -> Result<XHost> {
+        let url = url::Url::parse(grid_host).map_err(|_| Error::other("peer grid host is not a valid URL"))?;
+        if !matches!(url.scheme(), "http" | "https")
+            || !url.username().is_empty()
+            || url.password().is_some()
+            || url.query().is_some()
+            || url.fragment().is_some()
+            || url.path() != "/"
+        {
+            return Err(Error::other("peer grid host has an invalid URL shape"));
+        }
+        let url_host = url.host().ok_or_else(|| Error::other("peer grid host is missing a host"))?;
+        let topology_host = match url.port() {
+            Some(port) => format!("{url_host}:{port}"),
+            None => url_host.to_string(),
+        };
+        let explicit_port = url.port();
+        let name = match url_host {
+            url::Host::Domain(domain) => domain.to_string(),
+            url::Host::Ipv4(address) => address.to_string(),
+            url::Host::Ipv6(address) if explicit_port.is_none() => format!("[{address}]"),
+            url::Host::Ipv6(address) => address.to_string(),
+        };
+        let port = url
+            .port_or_known_default()
+            .filter(|port| *port > 0)
+            .ok_or_else(|| Error::other("peer grid host is missing a valid port"))?;
+        let host = XHost {
+            name,
+            port,
+            is_port_set: explicit_port.is_some(),
+        };
+        if topology_host != peer_host_port {
+            return Err(Error::other("peer topology host does not match its grid URL"));
+        }
+        Ok(host)
+    }
+
    fn build_clients_from_slots(
        slots: Vec<(String, Option<String>, bool)>,
    ) -> (Vec<Option<Self>>, Vec<Option<Self>>, Vec<String>) {
@@ -363,14 +412,14 @@ impl PeerRestClient {
            }

            let client = match grid_host {
-                Some(grid_host) => match XHost::try_from(peer_host_port.clone()) {
+                Some(grid_host) => match Self::parse_topology_host(&peer_host_port, &grid_host) {
                    Ok(host) => {
                        let mut client = PeerRestClient::new(host, grid_host);
                        client.topology_member = peer_host_port.clone();
                        Some(client)
                    }
                    Err(err) => {
-                        warn!(peer = %peer_host_port, "Xhost parse failed while constructing peer client: {err:?}");
+                        warn!(peer = %peer_host_port, "peer topology host parse failed while constructing peer client: {err:?}");
                        None
                    }
                },
@@ -519,9 +568,8 @@ impl PeerRestClient {
        }

        let grid_host = self.grid_host.clone();
-        let offline = Arc::clone(&self.offline);
-        let recovery_running = Arc::clone(&self.recovery_running);
-        let span = Self::recovery_monitor_span(&grid_host);
+        let offline = Arc::downgrade(&self.offline);
+        let recovery_running = Arc::downgrade(&self.recovery_running);
        // The offline flag and its recovery are the silent half of
        // rustfs/backlog#888: log the monitor's start and its success so an
        // "offline then back" episode leaves a trace on the observing node.
@@ -530,13 +578,34 @@ impl PeerRestClient {
            grid_host = %self.grid_host,
            "peer RPC connection marked offline after a network-like failure; starting background recovery monitor"
        );
+        drop(Self::spawn_recovery_monitor(grid_host, offline, recovery_running));
+    }
+
+    fn spawn_recovery_monitor(
+        grid_host: String,
+        offline: Weak<AtomicBool>,
+        recovery_running: Weak<AtomicBool>,
+    ) -> tokio::task::JoinHandle<()> {
+        let span = Self::recovery_monitor_span(&grid_host);
        super::spawn_background_monitor(span, async move {
            let mut delay = get_drive_active_check_interval();
            let connect_timeout = get_drive_active_check_timeout();

            for attempt in 1..=PEER_REST_RECOVERY_MAX_ATTEMPTS {
+                if offline.strong_count() == 0 || recovery_running.strong_count() == 0 {
+                    return;
+                }
                tokio::time::sleep(delay).await;
+                if offline.strong_count() == 0 || recovery_running.strong_count() == 0 {
+                    return;
+                }
                if Self::perform_connectivity_check(&grid_host, connect_timeout).await.is_ok() {
+                    let Some(offline) = offline.upgrade() else {
+                        return;
+                    };
+                    let Some(recovery_running) = recovery_running.upgrade() else {
+                        return;
+                    };
                    offline.store(false, Ordering::Release);
                    recovery_running.store(false, Ordering::Release);
                    info!(
@@ -556,8 +625,10 @@ impl PeerRestClient {
                attempts = PEER_REST_RECOVERY_MAX_ATTEMPTS,
                "peer recovery monitor reached max attempts; will retry on next request"
            );
-            recovery_running.store(false, Ordering::Release);
-        });
+            if let Some(recovery_running) = recovery_running.upgrade() {
+                recovery_running.store(false, Ordering::Release);
+            }
+        })
    }

    #[cfg(test)]
@@ -1440,6 +1511,22 @@ impl PeerRestClient {
    }

    pub async fn signal_service(&self, sig: u64, sub_sys: &str, dry_run: bool, _exec_at: SystemTime) -> Result<()> {
+        self.signal_service_checked(sig, sub_sys, dry_run).await.map(|_| ())
+    }
+
+    /// Report the KMS configuration fingerprint the peer is currently running.
+    ///
+    /// Sent as a dry-run reload signal so the peer answers without swapping its
+    /// own configuration. `None` means the peer has no KMS configuration. The
+    /// fingerprint is advisory and feeds cluster status reporting only, so the
+    /// response is not proof-signed.
+    pub async fn kms_config_fingerprint(&self) -> Result<Option<String>> {
+        self.signal_service_checked(SERVICE_SIGNAL_RELOAD_DYNAMIC, KMS_SIGNAL_SUBSYSTEM, true)
+            .await
+            .map(|response| response.config_fingerprint)
+    }
+
+    async fn signal_service_checked(&self, sig: u64, sub_sys: &str, dry_run: bool) -> Result<SignalServiceResponse> {
        self.finalize_result(
            async {
                let mut client = self.get_client().await?;
@@ -1460,7 +1547,7 @@ impl PeerRestClient {
                    return Err(Error::other(""));
                }
                validate_signal_service_protocol(sig, sub_sys, response.protocol_version)?;
-                Ok(())
+                Ok(response)
            }
            .await,
        )
@@ -1807,9 +1894,13 @@ fn tier_config_reload_status_outcome(status: tonic::Status) -> TierConfigReloadO
 mod tests {
    use super::*;
    use crate::config::com::STORAGE_CLASS_SUB_SYS;
+    use crate::layout::{disks_layout::DisksLayout, endpoints::SetupType};
+    use rustfs_config::{ENV_KUBERNETES_SERVICE_HOST, ENV_LOCAL_ENDPOINT_HOST, ENV_STARTUP_TOPOLOGY_WAIT_MODE};
    use serde_json::Value;
+    use serial_test::serial;
    use std::io::{self, Write};
    use std::sync::{Arc, Mutex};
+    use temp_env::async_with_vars;
    use tracing_subscriber::{Registry, fmt::MakeWriter, layer::SubscriberExt};

    #[test]
@@ -1927,30 +2018,115 @@ mod tests {
    fn build_clients_from_slots_preserves_missing_remote_topology_slots() {
        let slots = vec![
            ("127.0.0.1:9000".to_string(), None, true),
-            ("127.0.0.1:9001".to_string(), Some("http://127.0.0.1:9001".to_string()), false),
+            (
+                "rustfs-1.invalid:9001".to_string(),
+                Some("http://rustfs-1.invalid:9001".to_string()),
+                false,
+            ),
+            ("rustfs-2.invalid".to_string(), Some("http://rustfs-2.invalid".to_string()), false),
            ("127.0.0.1:notaport".to_string(), Some("http://127.0.0.1:notaport".to_string()), false),
            ("127.0.0.1:9003".to_string(), None, false),
        ];

        let (remote, all, remote_topology_hosts) = PeerRestClient::build_clients_from_slots(slots);

-        assert_eq!(remote.len(), 3, "local node is excluded but remote slots are not compacted away");
-        assert_eq!(all.len(), 4, "all slots preserve the sorted cluster topology shape");
+        assert_eq!(remote.len(), 4, "local node is excluded but remote slots are not compacted away");
+        assert_eq!(all.len(), 5, "all slots preserve the sorted cluster topology shape");
        assert_eq!(
            remote_topology_hosts,
            vec![
-                "127.0.0.1:9001".to_string(),
+                "rustfs-1.invalid:9001".to_string(),
+                "rustfs-2.invalid".to_string(),
                "127.0.0.1:notaport".to_string(),
                "127.0.0.1:9003".to_string()
            ]
        );
-        assert!(remote[0].is_some(), "valid remote peer should get a client");
-        assert!(remote[1].is_none(), "unparseable remote peer should remain observable as a missing slot");
-        assert!(remote[2].is_none(), "missing grid host should remain observable as a missing slot");
+        let unresolved = remote[0]
+            .as_ref()
+            .expect("temporarily unresolved remote peer should retain a client");
+        assert_eq!(unresolved.host.to_string(), "rustfs-1.invalid:9001");
+        let default_port = remote[1]
+            .as_ref()
+            .expect("temporarily unresolved scheme-default remote peer should retain a client");
+        assert_eq!(default_port.host.to_string(), "rustfs-2.invalid");
+        assert_eq!(default_port.host.port, 80);
+        assert!(!default_port.host.is_port_set);
+        assert!(remote[2].is_none(), "unparseable remote peer should remain observable as a missing slot");
+        assert!(remote[3].is_none(), "missing grid host should remain observable as a missing slot");
        assert!(all[0].is_none(), "local node is represented by the local server_info row");
        assert!(all[1].is_some());
-        assert!(all[2].is_none());
+        assert!(all[2].is_some());
        assert!(all[3].is_none());
+        assert!(all[4].is_none());
+    }
+
+    #[test]
+    fn topology_host_parser_preserves_names_and_bracketed_ipv6() {
+        let domain = PeerRestClient::parse_topology_host("rustfs-1.invalid", "https://rustfs-1.invalid")
+            .expect("unresolved HTTPS topology host should parse without DNS");
+        assert_eq!(domain.to_string(), "rustfs-1.invalid");
+        assert_eq!(domain.port, 443);
+        assert!(!domain.is_port_set);
+
+        let ipv6 = PeerRestClient::parse_topology_host("[2001:db8::1]:9000", "http://[2001:db8::1]:9000")
+            .expect("bracketed IPv6 topology host should parse without changing its identity");
+        assert_eq!(ipv6.to_string(), "[2001:db8::1]:9000");
+
+        let default_port_ipv6 = PeerRestClient::parse_topology_host("[2001:db8::2]", "http://[2001:db8::2]")
+            .expect("scheme-default IPv6 topology host should parse without DNS");
+        assert_eq!(default_port_ipv6.to_string(), "[2001:db8::2]");
+        assert_eq!(default_port_ipv6.port, 80);
+        assert!(!default_port_ipv6.is_port_set);
+
+        assert!(PeerRestClient::parse_topology_host("peer.invalid:0", "http://peer.invalid:0").is_err());
+        assert!(PeerRestClient::parse_topology_host("peer-a.invalid:9000", "http://peer-b.invalid:9000").is_err());
+        assert!(PeerRestClient::parse_topology_host("peer.invalid:9000", "http://peer.invalid:9000/unexpected").is_err());
+    }
+
+    #[tokio::test]
+    #[serial]
+    async fn unresolved_default_port_endpoint_topology_retains_all_peer_clients() {
+        let volumes = (0..4)
+            .map(|index| format!("http://rustfs-{index}.invalid:80/data{index}"))
+            .collect::<Vec<_>>();
+        let layout = DisksLayout::from_volumes(&volumes).expect("distributed default-port topology should parse");
+
+        async_with_vars(
+            [
+                (ENV_STARTUP_TOPOLOGY_WAIT_MODE, Some("orchestrated")),
+                (ENV_LOCAL_ENDPOINT_HOST, Some("rustfs-0.invalid")),
+                (ENV_KUBERNETES_SERVICE_HOST, None),
+            ],
+            async {
+                let (server_pools, setup_type) = EndpointServerPools::create_server_endpoints("0.0.0.0:80", &layout)
+                    .await
+                    .expect("explicit local identity should avoid peer DNS during endpoint construction");
+                assert_eq!(setup_type, SetupType::DistErasure);
+
+                let (remote, all, remote_topology_hosts) =
+                    PeerRestClient::build_clients_from_slots(server_pools.peer_grid_host_slots_sorted());
+                assert_eq!(remote.len(), 3);
+                assert!(
+                    remote.iter().all(Option::is_some),
+                    "unresolved remote peers must retain reconnectable clients"
+                );
+                assert_eq!(all.len(), 4);
+                assert_eq!(all.iter().filter(|client| client.is_none()).count(), 1);
+                assert_eq!(remote_topology_hosts.len(), 3);
+                assert!(
+                    remote_topology_hosts.iter().all(|host| !host.contains(':')),
+                    "scheme-default ports must preserve the legacy topology identity"
+                );
+                assert!(
+                    remote
+                        .iter()
+                        .flatten()
+                        .all(|client| client.host.port == 80 && !client.host.is_port_set),
+                    "scheme-default peers must retain the effective dial port"
+                );
+            },
+        )
+        .await;
    }

    #[test]
@@ -2198,6 +2374,19 @@ mod tests {
            .expect("full refresh compatibility is guarded by its scanner preflight");
    }

+    #[test]
+    fn dynamic_kms_config_requires_versioned_peer_acknowledgement() {
+        let err = validate_signal_service_protocol(SERVICE_SIGNAL_RELOAD_DYNAMIC, KMS_SIGNAL_SUBSYSTEM, 0)
+            .expect_err("an unversioned peer must not claim KMS config convergence");
+        assert!(err.to_string().contains("does not support dynamic"));
+        validate_signal_service_protocol(
+            SERVICE_SIGNAL_RELOAD_DYNAMIC,
+            KMS_SIGNAL_SUBSYSTEM,
+            rustfs_protos::DYNAMIC_CONFIG_PROTOCOL_VERSION,
+        )
+        .expect("a current peer should support dynamic KMS config");
+    }
+
    #[test]
    fn peer_rest_client_marks_network_like_errors() {
        assert!(PeerRestClient::is_network_like_error(&Error::other("transport error")));
@@ -2740,6 +2929,31 @@ mod tests {
        assert!(!client.offline.load(Ordering::Acquire));
    }

+    #[tokio::test(start_paused = true)]
+    async fn dropped_peer_client_releases_and_stops_its_recovery_monitor() {
+        let client = test_peer_client();
+        client.offline.store(true, Ordering::Release);
+        client.recovery_running.store(true, Ordering::Release);
+        let offline = Arc::downgrade(&client.offline);
+        let recovery_running = Arc::downgrade(&client.recovery_running);
+        let handle = PeerRestClient::spawn_recovery_monitor(client.grid_host.clone(), offline.clone(), recovery_running.clone());
+        let started = tokio::time::Instant::now();
+
+        drop(client);
+
+        assert!(offline.upgrade().is_none(), "detached recovery must not retain offline state");
+        assert!(
+            recovery_running.upgrade().is_none(),
+            "detached recovery must not retain its running state"
+        );
+        handle.await.expect("recovery monitor should not panic");
+        assert_eq!(
+            tokio::time::Instant::now(),
+            started,
+            "recovery monitor should stop before advancing to its first delayed probe"
+        );
+    }
+
    #[tokio::test]
    async fn peer_rest_client_finalize_result_keeps_online_for_app_errors_mentioning_unavailable() {
        // Regression: application error text containing "unavailable" (a
@@ -4814,9 +4814,11 @@ mod tests {
    async fn test_remote_disk_endpoints_with_different_schemes() {
        let test_cases = vec![
            ("http://server:9000", "server:9000"),
-            ("https://secure-server:443", "secure-server"), // Default HTTPS port is omitted
+            ("http://plain-server:80", "plain-server"),
+            ("http://plain-server", "plain-server"),
+            ("https://secure-server:443", "secure-server"),
            ("http://192.168.1.100:8080", "192.168.1.100:8080"),
-            ("https://secure-server", "secure-server"), // No port specified
+            ("https://secure-server", "secure-server"),
        ];

        for (url_str, expected_hostname) in test_cases {
@@ -53,12 +53,14 @@ use std::sync::LazyLock;
 use std::sync::{Arc, RwLock};
 use tokio::sync::{OwnedRwLockWriteGuard, RwLock as AsyncRwLock};
 use tracing::{debug, error, info, instrument, warn};
+use uuid::Uuid;

 pub const CONFIG_PREFIX: &str = "config";
 const SERVER_CONFIG_OBJECT: &str = "config/config.json";
+const CONFIG_TRANSACTION_LOCK_SUFFIX: &str = ".transaction.lock";

-// Server-config lock order: SERVER_CONFIG_LOCK -> distributed namespace lock
-// for SERVER_CONFIG_OBJECT. Readers and writers must never reverse this order.
+// Server-config lock order: SERVER_CONFIG_LOCK -> transaction lock ->
+// SERVER_CONFIG_OBJECT. Readers and writers must never reverse this order.
 static SERVER_CONFIG_LOCK: LazyLock<Arc<AsyncRwLock<()>>> = LazyLock::new(|| Arc::new(AsyncRwLock::new(())));

 fn config_task_join_error(operation: &'static str, error: tokio::task::JoinError) -> Error {
@@ -76,8 +78,11 @@ where
    T: Send + 'static,
 {
    tokio::spawn(async move {
-        // Lock order: SERVER_CONFIG_LOCK -> namespace write lock.
+        // Lock order: SERVER_CONFIG_LOCK -> transaction lock -> object lock.
        let _local_guard = SERVER_CONFIG_LOCK.write().await;
+        let transaction_lock = server_config_transaction_lock_path();
+        let transaction_lock = store.new_ns_lock(RUSTFS_META_BUCKET, &transaction_lock).await?;
+        let _transaction_guard = transaction_lock.get_write_lock(get_lock_acquire_timeout()).await?;
        let namespace_lock = store.new_ns_lock(RUSTFS_META_BUCKET, SERVER_CONFIG_OBJECT).await?;
        let _write_guard = namespace_lock.get_write_lock(get_lock_acquire_timeout()).await?;
        Ok(operation().await)
@@ -96,8 +101,11 @@ where
    T: Send + 'static,
 {
    tokio::spawn(async move {
-        // Lock order: SERVER_CONFIG_LOCK -> namespace read lock.
+        // Lock order: SERVER_CONFIG_LOCK -> transaction lock -> object lock.
        let _local_guard = SERVER_CONFIG_LOCK.read().await;
+        let transaction_lock = server_config_transaction_lock_path();
+        let transaction_lock = store.new_ns_lock(RUSTFS_META_BUCKET, &transaction_lock).await?;
+        let _transaction_guard = transaction_lock.get_read_lock(get_lock_acquire_timeout()).await?;
        let namespace_lock = store.new_ns_lock(RUSTFS_META_BUCKET, SERVER_CONFIG_OBJECT).await?;
        let _read_guard = namespace_lock.get_read_lock(get_lock_acquire_timeout()).await?;
        Ok(operation().await)
@@ -567,6 +575,21 @@ where
 }

 pub async fn save_config_with_opts<S>(api: Arc<S>, file: &str, data: Vec<u8>, opts: &ObjectOptions) -> Result<()>
+where
+    S: ObjectIO<
+            Error = Error,
+            RangeSpec = HTTPRangeSpec,
+            HeaderMap = HeaderMap,
+            ObjectOptions = ObjectOptions,
+            ObjectInfo = ObjectInfo,
+            GetObjectReader = GetObjectReader,
+            PutObjectReader = PutObjReader,
+        >,
+{
+    save_config_with_opts_and_metadata(api, file, data, opts).await.map(|_| ())
+}
+
+async fn save_config_with_opts_and_metadata<S>(api: Arc<S>, file: &str, data: Vec<u8>, opts: &ObjectOptions) -> Result<ObjectInfo>
 where
    S: ObjectIO<
            Error = Error,
@@ -579,11 +602,13 @@ where
        >,
 {
    let mut put_data = PutObjReader::from_vec(data);
-    if let Err(err) = api.put_object(RUSTFS_META_BUCKET, file, &mut put_data, opts).await {
-        error!("save_config_with_opts: err: {:?}, file: {}", err, file);
-        return Err(err);
+    match api.put_object(RUSTFS_META_BUCKET, file, &mut put_data, opts).await {
+        Ok(object_info) => Ok(object_info),
+        Err(err) => {
+            error!("save_config_with_opts: err: {:?}, file: {}", err, file);
+            Err(err)
+        }
    }
-    Ok(())
 }

 fn new_server_config() -> Config {
@@ -594,8 +619,12 @@ async fn new_and_save_server_config<S>(api: Arc<S>) -> Result<Config>
 where
    S: EcstoreObjectIO + StorageAdminApi + NamespaceLocking<Error = Error, NamespaceLock = rustfs_lock::NamespaceLockWrapper>,
 {
+    let snapshot = read_server_config_snapshot(api.clone()).await?;
+    if snapshot.object_exists() {
+        return Ok(snapshot.config.clone());
+    }
    let cfg = new_server_config();
-    save_server_config(api, &cfg).await?;
+    save_server_config_snapshot(api, &cfg, &snapshot).await?;

    Ok(cfg)
 }
@@ -617,6 +646,10 @@ pub fn server_config_path() -> String {
    SERVER_CONFIG_OBJECT.to_string()
 }

+fn server_config_transaction_lock_path() -> String {
+    format!("{}{CONFIG_TRANSACTION_LOCK_SUFFIX}", server_config_path())
+}
+
 fn storage_class_kvs_mut(cfg: &mut Config) -> &mut KVS {
    let sub_cfg = cfg.0.entry(STORAGE_CLASS_SUB_SYS.to_string()).or_insert_with(|| {
        let mut section = HashMap::new();
@@ -819,6 +852,9 @@ fn apply_external_scalar_config_map(
    let Some(config_value) = root.get(descriptor.subsystem_key) else {
        return Ok(false);
    };
+    if descriptor.subsystem_key == HEAL_SUB_SYS && config_value.is_null() {
+        return Ok(false);
+    }
    let overrides = decode_scalar_config_value(config_value, descriptor)?;

    if overrides.is_empty() {
@@ -1463,21 +1499,142 @@ fn build_audit_object(cfg: &Config) -> Map<String, Value> {
    build_target_object(cfg, &audit_target_descriptors())
 }

+fn sync_rendered_target_instance(existing: Value, rendered: Option<&Value>, valid_keys: &[&str]) -> Option<Value> {
+    match existing {
+        Value::Object(mut instance) => {
+            for key in valid_keys {
+                instance.remove(*key);
+            }
+            if let Some(Value::Object(rendered)) = rendered {
+                instance.extend(rendered.clone());
+            }
+            (!instance.is_empty()).then_some(Value::Object(instance))
+        }
+        Value::Array(entries) => {
+            let mut pending = rendered
+                .and_then(Value::as_object)
+                .map(|rendered| {
+                    rendered
+                        .iter()
+                        .filter_map(|(key, value)| parse_target_scalar_value(key, value).map(|value| (key.clone(), value)))
+                        .collect::<HashMap<_, _>>()
+                })
+                .unwrap_or_default();
+            let mut updated = Vec::with_capacity(entries.len().saturating_add(pending.len()));
+            for entry in entries {
+                let Some(entry_obj) = entry.as_object() else {
+                    updated.push(entry);
+                    continue;
+                };
+                let Some(key) = entry_obj.get("key").and_then(Value::as_str) else {
+                    updated.push(entry);
+                    continue;
+                };
+                if !valid_keys.contains(&key) {
+                    updated.push(entry);
+                    continue;
+                }
+                let Some(value) = pending.remove(key) else {
+                    continue;
+                };
+                let mut entry_obj = entry_obj.clone();
+                entry_obj.insert("value".to_string(), Value::String(value));
+                updated.push(Value::Object(entry_obj));
+            }
+            updated.extend(rendered_scalar_config_kvs_entries(&pending));
+            (!updated.is_empty()).then_some(Value::Array(updated))
+        }
+        value if rendered.is_none() => Some(value),
+        _ => rendered.cloned(),
+    }
+}
+
 fn sync_rendered_target_object(
    target_obj: &mut Map<String, Value>,
    rendered_target: &Map<String, Value>,
    descriptors: &[TargetConfigDescriptor],
 ) {
    for descriptor in descriptors {
-        match rendered_target.get(descriptor.external_key) {
-            Some(Value::Object(v)) => {
-                target_obj.insert(descriptor.external_key.to_string(), Value::Object(v.clone()));
-                target_obj.remove(descriptor.subsystem_key);
+        let existing = target_obj.remove(descriptor.external_key);
+        let alias = target_obj.remove(descriptor.subsystem_key);
+        let mut section = existing
+            .or(alias)
+            .and_then(|value| value.as_object().cloned())
+            .unwrap_or_default();
+        let rendered = rendered_target.get(descriptor.external_key).and_then(Value::as_object);
+
+        if is_target_instance_shorthand(&section, descriptor.valid_keys) {
+            let has_named_instances = rendered.is_some_and(|instances| instances.keys().any(|name| name != "default"));
+            if !has_named_instances {
+                if let Some(section) = sync_rendered_target_instance(
+                    Value::Object(section),
+                    rendered.and_then(|instances| instances.get("default")),
+                    descriptor.valid_keys,
+                ) {
+                    target_obj.insert(descriptor.external_key.to_string(), section);
+                }
+                continue;
            }
-            _ => {
-                target_obj.remove(descriptor.external_key);
-                target_obj.remove(descriptor.subsystem_key);
+
+            let mut nested = Map::new();
+            if let Some(default) = sync_rendered_target_instance(
+                Value::Object(section),
+                rendered.and_then(|instances| instances.get("default")),
+                descriptor.valid_keys,
+            ) {
+                nested.insert("default".to_string(), default);
            }
+            if let Some(rendered) = rendered {
+                for (instance_name, instance) in rendered {
+                    if instance_name != "default" {
+                        nested.insert(instance_name.clone(), instance.clone());
+                    }
+                }
+            }
+            if !nested.is_empty() {
+                target_obj.insert(descriptor.external_key.to_string(), Value::Object(nested));
+            }
+            continue;
+        }
+
+        if let Some(default_alias) = section.remove(DEFAULT_DELIMITER) {
+            if let Some(default) = section.get_mut("default") {
+                if let Some(alias) = sync_rendered_target_instance(default_alias, None, descriptor.valid_keys) {
+                    match (default, alias) {
+                        (Value::Object(default), Value::Object(alias)) => {
+                            for (key, value) in alias {
+                                default.entry(key).or_insert(value);
+                            }
+                        }
+                        (Value::Array(default), Value::Array(alias)) => default.extend(alias),
+                        _ => {}
+                    }
+                }
+            } else {
+                section.insert("default".to_string(), default_alias);
+            }
+        }
+
+        let mut merged = Map::new();
+        for (instance_name, instance) in section {
+            if let Some(instance) = sync_rendered_target_instance(
+                instance,
+                rendered.and_then(|instances| instances.get(&instance_name)),
+                descriptor.valid_keys,
+            ) {
+                merged.insert(instance_name, instance);
+            }
+        }
+        if let Some(rendered) = rendered {
+            for (instance_name, instance) in rendered {
+                if !merged.contains_key(instance_name) {
+                    merged.insert(instance_name.clone(), instance.clone());
+                }
+            }
+        }
+
+        if !merged.is_empty() {
+            target_obj.insert(descriptor.external_key.to_string(), Value::Object(merged));
        }
    }
 }
@@ -1496,6 +1653,14 @@ fn encode_server_config_blob(cfg: &Config, seed: Option<&[u8]>) -> Result<Vec<u8
        Some(Value::Object(v)) => v,
        _ => Map::new(),
    };
+    for key in [
+        storageclass::CLASS_STANDARD,
+        storageclass::CLASS_RRS,
+        storageclass::OPTIMIZE,
+        storageclass::INLINE_BLOCK,
+    ] {
+        sc_obj.remove(key);
+    }
    for (k, v) in build_storageclass_object(cfg) {
        sc_obj.insert(k, v);
    }
@@ -1503,7 +1668,10 @@ fn encode_server_config_blob(cfg: &Config, seed: Option<&[u8]>) -> Result<Vec<u8
    root.remove("storage_class");

    for descriptor in [scanner_config_descriptor(), heal_config_descriptor()] {
-        let existing = root.remove(descriptor.subsystem_key);
+        let mut existing = root.remove(descriptor.subsystem_key);
+        if descriptor.subsystem_key == HEAL_SUB_SYS && existing.as_ref().is_some_and(Value::is_null) {
+            existing = None;
+        }
        let rendered = build_scalar_config_object(cfg, descriptor);
        if let Some(config_value) = sync_rendered_scalar_config_value(existing, &rendered, descriptor)? {
            root.insert(descriptor.subsystem_key.to_string(), config_value);
@@ -1560,6 +1728,7 @@ fn is_standard_object_server_config(data: &[u8]) -> bool {
    matches!(root.get("version"), Some(Value::String(v)) if !v.trim().is_empty())
        && matches!(root.get("storageclass"), Some(Value::Object(_)))
        && !root.contains_key("storage_class")
+        && !matches!(root.get(HEAL_SUB_SYS), Some(Value::Null))
 }

 fn configs_semantically_equal(lhs: &Config, rhs: &Config) -> bool {
@@ -1593,7 +1762,7 @@ where
            FileInfo = FileInfo,
            ObjectToDelete = ObjectToDelete,
            DeletedObject = DeletedObject,
-        >,
+        > + NamespaceLocking<Error = Error, NamespaceLock = rustfs_lock::NamespaceLockWrapper>,
 {
    if let Some(decrypt) = &decrypt_fn {
        register_server_config_decrypt_fn(decrypt.clone());
@@ -1601,14 +1770,7 @@ where

    let config_file = server_config_path();
    match api
-        .get_object_info(
-            RUSTFS_META_BUCKET,
-            &config_file,
-            &ObjectOptions {
-                no_lock: true,
-                ..Default::default()
-            },
-        )
+        .get_object_info(RUSTFS_META_BUCKET, &config_file, &ObjectOptions::default())
        .await
    {
        Ok(_) => {
@@ -1624,7 +1786,6 @@ where

    let opts = ObjectOptions {
        max_parity: true,
-        no_lock: true,
        ..Default::default()
    };

@@ -1677,7 +1838,33 @@ where
        }
    };

-    match save_config(api, &config_file, normalized).await {
+    let snapshot = match read_server_config_snapshot(api.clone()).await {
+        Ok(snapshot) => snapshot,
+        Err(err) => {
+            warn!("recheck target server config failed, skip migration: {:?}", err);
+            return;
+        }
+    };
+    if snapshot.object_exists() {
+        debug!("server config was created while legacy migration was preparing, skip migration");
+        return;
+    }
+
+    match save_config_with_opts(
+        api,
+        &config_file,
+        normalized,
+        &ObjectOptions {
+            max_parity: true,
+            http_preconditions: Some(HTTPPreconditions {
+                if_none_match: Some("*".to_string()),
+                ..Default::default()
+            }),
+            ..Default::default()
+        },
+    )
+    .await
+    {
        Ok(()) => {
            info!("Migrated compatible server config from legacy metadata bucket");
        }
@@ -1769,8 +1956,13 @@ where
 {
    let config_file = server_config_path();

-    // Try to read the configuration file
-    match read_config_no_lock(api.clone(), &config_file).await {
+    // Try to read the configuration file.
+    let data = if namespace_lock_held {
+        read_config_no_lock(api.clone(), &config_file).await
+    } else {
+        read_config(api.clone(), &config_file).await
+    };
+    match data {
        Ok(data) => read_server_config(api, &data, namespace_lock_held).await,
        Err(Error::ConfigNotFound) => handle_missing_config(api, "Read the main configuration", namespace_lock_held).await,
        Err(err) => handle_config_read_error(err, &config_file),
@@ -1787,7 +1979,12 @@ where
        warn!("Received empty configuration data, try to reread from '{}'", config_file);

        // Try to read the configuration again
-        match read_config_no_lock(api.clone(), &config_file).await {
+        let data = if namespace_lock_held {
+            read_config_no_lock(api.clone(), &config_file).await
+        } else {
+            read_config(api.clone(), &config_file).await
+        };
+        match data {
            Ok(cfg_data) => {
                let cfg = decode_persisted_server_config(&cfg_data)?;
                return Ok(cfg.merge());
@@ -2036,11 +2233,16 @@ pub struct ServerConfigSnapshot {
    raw: Option<Vec<u8>>,
    seed: Option<Vec<u8>>,
    etag: Option<String>,
+    generation: Option<Uuid>,
    _local_guard: OwnedRwLockWriteGuard<()>,
    _guard: rustfs_lock::NamespaceLockGuard,
 }

 impl ServerConfigSnapshot {
+    pub fn object_exists(&self) -> bool {
+        self.raw.is_some()
+    }
+
    pub fn ensure_lock_held(&self) -> Result<()> {
        if self._guard.is_lock_lost() {
            return Err(Error::other("server config transaction lock was lost"));
@@ -2051,12 +2253,34 @@ impl ServerConfigSnapshot {
    pub fn is_lock_lost(&self) -> bool {
        self._guard.is_lock_lost()
    }
+
+    pub fn generation(&self) -> Option<Uuid> {
+        self.generation
+    }
 }

-/// Read a server config transaction snapshot while holding the same local and
-/// distributed write locks used by every other server-config writer. Internal
-/// reads and the later conditional write use no-lock object I/O; the guards
-/// remain live until the snapshot is dropped.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct ServerConfigSaveResult {
+    persisted: bool,
+    generation: Option<Uuid>,
+}
+
+impl ServerConfigSaveResult {
+    pub fn persisted(&self) -> bool {
+        self.persisted
+    }
+
+    pub fn generation(&self) -> Option<Uuid> {
+        self.generation
+    }
+}
+
+/// Read a server config transaction snapshot while holding a dedicated
+/// transaction lock. The config object's normal namespace lock remains
+/// available to fence reads and the conditional write at commit time.
+/// The transaction guard remains live until the snapshot is dropped,
+/// serializing persistence and history ordering across admin nodes. Runtime
+/// state is reloaded from the durable object after this guard is released.
 pub async fn read_server_config_snapshot<S>(api: Arc<S>) -> Result<ServerConfigSnapshot>
 where
    S: ObjectIO<
@@ -2071,12 +2295,10 @@ where
 {
    let config_file = server_config_path();
    let local_guard = SERVER_CONFIG_LOCK.clone().write_owned().await;
-    let lock = api.new_ns_lock(RUSTFS_META_BUCKET, &config_file).await?;
+    let transaction_lock = server_config_transaction_lock_path();
+    let lock = api.new_ns_lock(RUSTFS_META_BUCKET, &transaction_lock).await?;
    let guard = lock.get_write_lock(get_lock_acquire_timeout()).await?;
-    let read_options = ObjectOptions {
-        no_lock: true,
-        ..Default::default()
-    };
+    let read_options = ObjectOptions::default();
    match read_config_with_metadata_inner(api, &config_file, &read_options, true).await {
        Ok((raw, object_info)) => {
            let (config, seed) = decode_persisted_server_config_with_seed(&raw)?;
@@ -2085,6 +2307,7 @@ where
                raw: Some(raw),
                seed: Some(seed),
                etag: object_info.etag,
+                generation: object_info.data_dir.filter(|generation| !generation.is_nil()),
                _local_guard: local_guard,
                _guard: guard,
            })
@@ -2094,6 +2317,7 @@ where
            raw: None,
            seed: None,
            etag: None,
+            generation: None,
            _local_guard: local_guard,
            _guard: guard,
        }),
@@ -2108,6 +2332,27 @@ where
 /// lock, so a concurrent update or transaction lease loss cannot commit an
 /// unfenced overwrite.
 pub async fn save_server_config_snapshot<S>(api: Arc<S>, cfg: &Config, snapshot: &ServerConfigSnapshot) -> Result<bool>
+where
+    S: ObjectIO<
+            Error = Error,
+            RangeSpec = HTTPRangeSpec,
+            HeaderMap = HeaderMap,
+            ObjectOptions = ObjectOptions,
+            ObjectInfo = ObjectInfo,
+            GetObjectReader = GetObjectReader,
+            PutObjectReader = PutObjReader,
+        > + NamespaceLocking<Error = Error, NamespaceLock = rustfs_lock::NamespaceLockWrapper>,
+{
+    save_server_config_snapshot_with_generation(api, cfg, snapshot)
+        .await
+        .map(|result| result.persisted())
+}
+
+pub async fn save_server_config_snapshot_with_generation<S>(
+    api: Arc<S>,
+    cfg: &Config,
+    snapshot: &ServerConfigSnapshot,
+) -> Result<ServerConfigSaveResult>
 where
    S: ObjectIO<
            Error = Error,
@@ -2126,13 +2371,19 @@ where
        && configs_semantically_equal(&snapshot.config, cfg)
    {
        debug!("server config unchanged and already in standard object shape, skip write");
-        return Ok(false);
+        return Ok(ServerConfigSaveResult {
+            persisted: false,
+            generation: snapshot.generation(),
+        });
    }

    let data = encode_server_config_blob(cfg, snapshot.seed.as_deref())?;
    if snapshot.raw.as_deref().is_some_and(|current| current == data.as_slice()) {
        debug!("server config bytes unchanged after encode, skip write");
-        return Ok(false);
+        return Ok(ServerConfigSaveResult {
+            persisted: false,
+            generation: snapshot.generation(),
+        });
    }

    let http_preconditions = if snapshot.raw.is_some() {
@@ -2152,19 +2403,22 @@ where
        }
    };

-    save_config_with_opts(
+    snapshot.ensure_lock_held()?;
+    let object_info = save_config_with_opts_and_metadata(
        api,
        &config_file,
        data,
        &ObjectOptions {
            max_parity: true,
-            no_lock: true,
            http_preconditions: Some(http_preconditions),
            ..Default::default()
        },
    )
    .await?;
-    Ok(true)
+    Ok(ServerConfigSaveResult {
+        persisted: true,
+        generation: object_info.data_dir.filter(|generation| !generation.is_nil()),
+    })
 }

 /// Saves the server config while an upper layer holds the namespace write
@@ -2301,8 +2555,9 @@ mod tests {
    use super::{
        SERVER_CONFIG_LOCK, ServerConfigSnapshot, apply_dynamic_config_for_sub_sys_with, config_task_join_error,
        configs_semantically_equal, decode_server_config_blob, encode_server_config_blob, is_standard_object_server_config,
-        lookup_configs, read_config, read_config_preserve_empty, read_config_with_metadata, read_config_without_migrate,
-        read_server_config_snapshot, save_server_config, save_server_config_snapshot, server_config_path, storage_class_kvs_mut,
+        lookup_configs, new_and_save_server_config, read_config, read_config_preserve_empty, read_config_with_metadata,
+        read_config_without_migrate, read_server_config_snapshot, save_server_config, save_server_config_snapshot,
+        save_server_config_snapshot_with_generation, server_config_transaction_lock_path, storage_class_kvs_mut,
    };
    use crate::config::{audit, heal, notify, oidc, scanner};
    use crate::disk::endpoint::Endpoint;
@@ -2311,7 +2566,9 @@ mod tests {
    use crate::object_api::{GetObjectReader, ObjectInfo, ObjectOptions, PutObjReader};
    use crate::runtime::sources as runtime_sources;
    use crate::set_disk::SetDisks;
-    use crate::storage_api_contracts::{admin::StorageAdminApi, namespace::NamespaceLocking as _, range::HTTPRangeSpec};
+    use crate::storage_api_contracts::{
+        admin::StorageAdminApi, namespace::NamespaceLocking as _, object::HTTPPreconditions, range::HTTPRangeSpec,
+    };
    use http::HeaderMap;
    use rustfs_config::audit::{AUDIT_AMQP_SUB_SYS, AUDIT_KAFKA_SUB_SYS, AUDIT_MQTT_SUB_SYS, AUDIT_WEBHOOK_SUB_SYS};
    use rustfs_config::notify::{
@@ -3104,6 +3361,85 @@ mod tests {
        );
    }

+    #[test]
+    fn root_heal_null_decodes_as_no_override_and_is_canonicalized_on_save() {
+        let seed = br#"{
+          "version":"33",
+          "storageclass":{"standard":"","rrs":""},
+          "heal":null,
+          "future_root":{"mode":"keep"},
+          "openid":{"default":{
+            "config_url":"https://issuer.example/.well-known/openid-configuration",
+            "client_id":"console",
+            "client_secret":"oidc-secret",
+            "future_provider_control":"keep"
+          }},
+          "notify":{"webhook":{"primary":{
+            "enable":true,
+            "endpoint":"https://notify.example/hook",
+            "auth_token":"notify-secret",
+            "future_notify_control":"keep"
+          }}},
+          "logger":{"webhook":{"primary":{
+            "enable":true,
+            "endpoint":"https://audit.example/hook",
+            "auth_token":"audit-secret",
+            "future_audit_control":"keep"
+          }}}
+        }"#;
+
+        let cfg = decode_server_config_blob(seed).expect("root heal null should mean no persisted override");
+        assert!(cfg.get_value(HEAL_SUB_SYS, DEFAULT_DELIMITER).is_none());
+        assert!(!is_standard_object_server_config(seed));
+
+        let encoded = encode_server_config_blob(&cfg, Some(seed)).expect("legacy seed should canonicalize on an authorized save");
+        let value: Value = serde_json::from_slice(&encoded).expect("canonical config should be valid JSON");
+        assert!(value.get(HEAL_SUB_SYS).is_none());
+        assert_eq!(value["future_root"]["mode"].as_str(), Some("keep"));
+        assert_eq!(value["openid"]["default"]["client_secret"].as_str(), Some("oidc-secret"));
+        assert_eq!(value["openid"]["default"]["future_provider_control"].as_str(), Some("keep"));
+        assert_eq!(value["notify"]["webhook"]["primary"]["auth_token"].as_str(), Some("notify-secret"));
+        assert_eq!(value["notify"]["webhook"]["primary"]["future_notify_control"].as_str(), Some("keep"));
+        assert_eq!(value["logger"]["webhook"]["primary"]["auth_token"].as_str(), Some("audit-secret"));
+        assert_eq!(value["logger"]["webhook"]["primary"]["future_audit_control"].as_str(), Some("keep"));
+        assert!(is_standard_object_server_config(&encoded));
+    }
+
+    #[test]
+    fn invalid_scalar_and_nested_null_config_shapes_remain_rejected() {
+        let invalid_sections = [
+            r#""scanner":null"#,
+            r#""heal":"""#,
+            r#""heal":false"#,
+            r#""heal":0"#,
+            r#""heal":{"default":null}"#,
+            r#""heal":{"_":null}"#,
+            r#""heal":{"bitrot_cycle":null}"#,
+            r#""heal":[{"key":"bitrot_cycle","value":null}]"#,
+        ];
+
+        for section in invalid_sections {
+            let input = format!(r#"{{"version":"33","storageclass":{{"standard":"","rrs":""}},{section}}}"#);
+            let err = decode_server_config_blob(input.as_bytes()).expect_err("invalid scalar shape must remain rejected");
+            assert!(
+                err.to_string().contains("expected"),
+                "invalid section {section} returned an unrelated error: {err}"
+            );
+        }
+    }
+
+    #[test]
+    fn valid_heal_object_and_kvs_array_shapes_remain_accepted() {
+        let empty_object = br#"{"version":"33","storageclass":{"standard":"","rrs":""},"heal":{}}"#;
+        let cfg = decode_server_config_blob(empty_object).expect("empty heal object should decode as no override");
+        assert!(cfg.get_value(HEAL_SUB_SYS, DEFAULT_DELIMITER).is_none());
+
+        let kvs_array =
+            br#"{"version":"33","storageclass":{"standard":"","rrs":""},"heal":[{"key":"bitrot_cycle","value":"off"}]}"#;
+        let cfg = decode_server_config_blob(kvs_array).expect("heal KVS array should decode");
+        assert!(cfg.get_value(HEAL_SUB_SYS, DEFAULT_DELIMITER).is_some());
+    }
+
    #[test]
    fn scanner_update_preserves_unknown_root_and_oidc_provider_fields() {
        let seed = br#"{
@@ -3131,6 +3467,171 @@ mod tests {
        assert_eq!(value["openid"]["default"]["client_id"].as_str(), Some("console"));
    }

+    #[test]
+    fn storageclass_reset_removes_stale_inline_block_from_seed() {
+        let seed = br#"{
+          "version":"33",
+          "storageclass":{
+            "standard":"EC:2",
+            "rrs":"EC:1",
+            "optimize":"availability",
+            "inline_block":"64KiB",
+            "future_storage_control":"keep"
+          }
+        }"#;
+
+        let encoded = encode_server_config_blob(&Config::new(), Some(seed)).expect("storageclass reset should encode");
+        let value: Value = serde_json::from_slice(&encoded).expect("encoded config should be valid json");
+        let storageclass = value["storageclass"].as_object().expect("storageclass object");
+
+        assert!(storageclass.get(crate::config::storageclass::INLINE_BLOCK).is_none());
+        assert_eq!(storageclass["future_storage_control"].as_str(), Some("keep"));
+    }
+
+    #[test]
+    fn target_update_preserves_unknown_fields_without_restoring_removed_instances() {
+        let seed = br#"{
+          "version":"33",
+          "storageclass":{"standard":"","rrs":""},
+          "notify":{"webhook":{
+            "primary":{
+              "enable":true,
+              "endpoint":"https://notify.example/old",
+              "auth_token":"notify-secret",
+              "future_control":"keep"
+            },
+            "removed":{"enable":true,"endpoint":"https://notify.example/removed"},
+            "retained":{"enable":true,"endpoint":"https://notify.example/retained","future_control":"keep"},
+            "enable":{"enable":true,"endpoint":"https://notify.example/named-enable","future_control":"keep"}
+          }}
+        }"#;
+        let mut cfg = decode_server_config_blob(seed).expect("target seed should decode");
+        let webhook = cfg
+            .0
+            .get_mut(NOTIFY_WEBHOOK_SUB_SYS)
+            .expect("notify webhook subsystem should exist");
+        webhook
+            .get_mut("primary")
+            .expect("primary target should exist")
+            .insert(rustfs_config::WEBHOOK_ENDPOINT.to_string(), "https://notify.example/new".to_string());
+        webhook.remove("removed");
+        webhook.remove("retained");
+
+        let encoded = encode_server_config_blob(&cfg, Some(seed)).expect("target update should encode");
+        let value: Value = serde_json::from_slice(&encoded).expect("encoded config should be valid json");
+        let webhook = value["notify"]["webhook"].as_object().expect("webhook section");
+
+        assert_eq!(webhook["primary"]["endpoint"].as_str(), Some("https://notify.example/new"));
+        assert_eq!(webhook["primary"]["auth_token"].as_str(), Some("notify-secret"));
+        assert_eq!(webhook["primary"]["future_control"].as_str(), Some("keep"));
+        assert!(webhook.get("removed").is_none());
+        assert_eq!(webhook["retained"]["future_control"].as_str(), Some("keep"));
+        assert!(webhook["retained"].get("enable").is_none());
+        assert!(webhook["retained"].get("endpoint").is_none());
+        assert_eq!(webhook["enable"]["endpoint"].as_str(), Some("https://notify.example/named-enable"));
+        assert_eq!(webhook["enable"]["future_control"].as_str(), Some("keep"));
+    }
+
+    #[test]
+    fn shorthand_target_update_preserves_shape_and_unknown_nested_fields() {
+        let seed = br#"{
+          "version":"33",
+          "storageclass":{"standard":"","rrs":""},
+          "notify":{"webhook":{
+            "enable":true,
+            "endpoint":"https://notify.example/old",
+            "future_control":{"endpoint":"leave-untouched","mode":"keep"}
+          }}
+        }"#;
+        let mut cfg = decode_server_config_blob(seed).expect("shorthand target should decode");
+        cfg.0
+            .get_mut(NOTIFY_WEBHOOK_SUB_SYS)
+            .and_then(|targets| targets.get_mut(DEFAULT_DELIMITER))
+            .expect("default webhook target should exist")
+            .insert(rustfs_config::WEBHOOK_ENDPOINT.to_string(), "https://notify.example/new".to_string());
+
+        let encoded = encode_server_config_blob(&cfg, Some(seed)).expect("shorthand target update should encode");
+        let value: Value = serde_json::from_slice(&encoded).expect("encoded config should be valid json");
+        let webhook = value["notify"]["webhook"].as_object().expect("webhook shorthand object");
+
+        assert_eq!(webhook["endpoint"].as_str(), Some("https://notify.example/new"));
+        assert!(webhook.get("default").is_none());
+        assert_eq!(webhook["future_control"]["endpoint"].as_str(), Some("leave-untouched"));
+        assert_eq!(webhook["future_control"]["mode"].as_str(), Some("keep"));
+        let decoded = decode_server_config_blob(&encoded).expect("updated shorthand target should remain decodable");
+        assert_eq!(
+            decoded
+                .get_value(NOTIFY_WEBHOOK_SUB_SYS, DEFAULT_DELIMITER)
+                .expect("updated default webhook target")
+                .get(rustfs_config::WEBHOOK_ENDPOINT),
+            "https://notify.example/new"
+        );
+    }
+
+    #[test]
+    fn target_kvs_update_preserves_unknown_entries_and_attributes() {
+        let seed = br#"{
+          "version":"33",
+          "storageclass":{"standard":"","rrs":""},
+          "notify":{"webhook":{"primary":[
+            {"key":"enable","value":"on","hidden_if_empty":false},
+            {"key":"endpoint","value":"https://notify.example/old","future_attribute":"keep-endpoint"},
+            {"key":"future_control","value":"keep","future_attribute":"keep-control"}
+          ]}}
+        }"#;
+        let mut cfg = decode_server_config_blob(seed).expect("target KVS seed should decode");
+        cfg.0
+            .get_mut(NOTIFY_WEBHOOK_SUB_SYS)
+            .and_then(|targets| targets.get_mut("primary"))
+            .expect("primary webhook target should exist")
+            .insert(rustfs_config::WEBHOOK_ENDPOINT.to_string(), "https://notify.example/new".to_string());
+
+        let encoded = encode_server_config_blob(&cfg, Some(seed)).expect("target KVS update should encode");
+        let value: Value = serde_json::from_slice(&encoded).expect("encoded config should be valid json");
+        let entries = value["notify"]["webhook"]["primary"]
+            .as_array()
+            .expect("target KVS shape should be preserved");
+        let endpoint = entries
+            .iter()
+            .find(|entry| entry["key"].as_str() == Some(rustfs_config::WEBHOOK_ENDPOINT))
+            .expect("endpoint entry should remain");
+        let future = entries
+            .iter()
+            .find(|entry| entry["key"].as_str() == Some("future_control"))
+            .expect("unknown target entry should remain");
+
+        assert_eq!(endpoint["value"].as_str(), Some("https://notify.example/new"));
+        assert_eq!(endpoint["future_attribute"].as_str(), Some("keep-endpoint"));
+        assert_eq!(future["value"].as_str(), Some("keep"));
+        assert_eq!(future["future_attribute"].as_str(), Some("keep-control"));
+    }
+
+    #[test]
+    fn target_default_alias_is_canonicalized_without_losing_unknown_fields() {
+        let seed = br#"{
+          "version":"33",
+          "storageclass":{"standard":"","rrs":""},
+          "notify":{"webhook":{
+            "_":{"enable":false,"endpoint":"https://notify.example/alias","future_alias":"keep"},
+            "default":{"enable":true,"endpoint":"https://notify.example/default","future_default":"keep"}
+          }}
+        }"#;
+        let cfg = decode_server_config_blob(seed).expect("dual default aliases should decode");
+        let expected_endpoint = cfg
+            .get_value(NOTIFY_WEBHOOK_SUB_SYS, DEFAULT_DELIMITER)
+            .expect("default webhook target should exist")
+            .get(rustfs_config::WEBHOOK_ENDPOINT);
+
+        let encoded = encode_server_config_blob(&cfg, Some(seed)).expect("default alias should canonicalize");
+        let value: Value = serde_json::from_slice(&encoded).expect("encoded config should be valid json");
+        let webhook = value["notify"]["webhook"].as_object().expect("webhook section");
+
+        assert!(webhook.get(DEFAULT_DELIMITER).is_none());
+        assert_eq!(webhook["default"]["endpoint"].as_str(), Some(expected_endpoint.as_str()));
+        assert_eq!(webhook["default"]["future_alias"].as_str(), Some("keep"));
+        assert_eq!(webhook["default"]["future_default"].as_str(), Some("keep"));
+    }
+
    #[test]
    fn test_scanner_config_changes_are_semantically_significant() {
        let baseline = Config::new();
@@ -4124,6 +4625,7 @@ mod tests {

    /// What reads of the config object currently return.
    enum RecoveryReadState {
+        Missing,
        Blob(Vec<u8>),
        QuorumError,
    }
@@ -4136,6 +4638,7 @@ mod tests {
        heal_calls: AtomicUsize,
        write_calls: AtomicUsize,
        last_put_no_lock: AtomicBool,
+        last_put_preconditions: Mutex<Option<HTTPPreconditions>>,
        revision: AtomicUsize,
        drive_counts: Vec<usize>,
        lock_manager: Arc<rustfs_lock::GlobalLockManager>,
@@ -4150,6 +4653,7 @@ mod tests {
                heal_calls: AtomicUsize::new(0),
                write_calls: AtomicUsize::new(0),
                last_put_no_lock: AtomicBool::new(false),
+                last_put_preconditions: Mutex::new(None),
                revision: AtomicUsize::new(1),
                drive_counts: vec![2],
                lock_manager: Arc::new(rustfs_lock::GlobalLockManager::new()),
@@ -4206,6 +4710,7 @@ mod tests {
            _opts: &ObjectOptions,
        ) -> Result<GetObjectReader> {
            let data = match &*self.state.lock().expect("state lock poisoned") {
+                RecoveryReadState::Missing => return Err(Error::ConfigNotFound),
                RecoveryReadState::Blob(data) => data.clone(),
                RecoveryReadState::QuorumError => return Err(Error::ErasureReadQuorum),
            };
@@ -4213,6 +4718,9 @@ mod tests {
                size: data.len() as i64,
                actual_size: data.len() as i64,
                etag: Some(format!("config-{}", self.revision.load(Ordering::SeqCst))),
+                data_dir: Some(uuid::Uuid::from_u128(
+                    u128::try_from(self.revision.load(Ordering::SeqCst)).expect("test revision should fit in u128"),
+                )),
                ..Default::default()
            };
            Ok(GetObjectReader {
@@ -4231,15 +4739,19 @@ mod tests {
            opts: &ObjectOptions,
        ) -> Result<ObjectInfo> {
            let current_etag = format!("config-{}", self.revision.load(Ordering::SeqCst));
+            let object_exists = matches!(&*self.state.lock().expect("state lock poisoned"), RecoveryReadState::Blob(_));
            if let Some(preconditions) = &opts.http_preconditions
-                && (preconditions.if_match_value().is_some_and(|etag| etag != current_etag)
-                    || preconditions.if_none_match_value() == Some("*"))
+                && (preconditions
+                    .if_match_value()
+                    .is_some_and(|etag| !object_exists || etag != current_etag)
+                    || (object_exists && preconditions.if_none_match_value() == Some("*")))
            {
                return Err(Error::PreconditionFailed);
            }
            let mut body = Vec::new();
            data.stream.read_to_end(&mut body).await?;
            self.last_put_no_lock.store(opts.no_lock, Ordering::SeqCst);
+            *self.last_put_preconditions.lock().expect("preconditions lock poisoned") = opts.http_preconditions.clone();
            self.write_calls.fetch_add(1, Ordering::SeqCst);
            *self.state.lock().expect("state lock poisoned") = RecoveryReadState::Blob(body.clone());
            let revision = self.revision.fetch_add(1, Ordering::SeqCst) + 1;
@@ -4247,6 +4759,7 @@ mod tests {
                size: i64::try_from(body.len()).expect("test config should fit in i64"),
                actual_size: i64::try_from(body.len()).expect("test config should fit in i64"),
                etag: Some(format!("config-{revision}")),
+                data_dir: Some(uuid::Uuid::from_u128(u128::try_from(revision).expect("test revision should fit in u128"))),
                ..Default::default()
            })
        }
@@ -4284,10 +4797,18 @@ mod tests {
            .expect("scanner-only config change should be persisted");

        assert_eq!(store.write_calls.load(Ordering::SeqCst), 1);
-        assert!(store.last_put_no_lock.load(Ordering::SeqCst));
+        assert!(!store.last_put_no_lock.load(Ordering::SeqCst));
+        let preconditions = store
+            .last_put_preconditions
+            .lock()
+            .expect("preconditions lock poisoned")
+            .clone()
+            .expect("existing config update must be conditional");
+        assert_eq!(preconditions.if_match_value(), Some("config-1"));
+        assert_eq!(preconditions.if_none_match_value(), None);
        assert_eq!(
            store.lock_resources.lock().expect("lock resources mutex poisoned").as_slice(),
-            &[server_config_path()]
+            &[server_config_transaction_lock_path()]
        );
        let decoded = read_config_without_migrate(store)
            .await
@@ -4301,6 +4822,73 @@ mod tests {
        );
    }

+    #[tokio::test]
+    async fn server_config_snapshot_save_returns_committed_generation() {
+        let baseline = encode_server_config_blob(&Config::new(), None).expect("baseline config should encode");
+        let store = Arc::new(RecoveryMockStore::new(RecoveryReadState::Blob(baseline), None));
+        let snapshot = read_server_config_snapshot(store.clone())
+            .await
+            .expect("server config snapshot");
+
+        let result = save_server_config_snapshot_with_generation(store, &config_with_scanner_cycle("61"), &snapshot)
+            .await
+            .expect("conditional config save");
+
+        assert!(result.persisted());
+        assert_eq!(result.generation(), Some(uuid::Uuid::from_u128(2)));
+    }
+
+    #[tokio::test]
+    async fn missing_server_config_is_created_with_if_none_match() {
+        let store = Arc::new(RecoveryMockStore::new(RecoveryReadState::Missing, None));
+        let cfg = config_with_scanner_cycle("61");
+
+        save_server_config(store.clone(), &cfg)
+            .await
+            .expect("missing config should be created conditionally");
+
+        assert_eq!(store.write_calls.load(Ordering::SeqCst), 1);
+        assert!(!store.last_put_no_lock.load(Ordering::SeqCst));
+        let preconditions = store
+            .last_put_preconditions
+            .lock()
+            .expect("preconditions lock poisoned")
+            .clone()
+            .expect("missing config create must be conditional");
+        assert_eq!(preconditions.if_match_value(), None);
+        assert_eq!(preconditions.if_none_match_value(), Some("*"));
+        let persisted = read_config_without_migrate(store)
+            .await
+            .expect("created config should reload");
+        assert_eq!(
+            persisted
+                .get_value(SCANNER_SUB_SYS, DEFAULT_DELIMITER)
+                .expect("persisted scanner config")
+                .get(SCANNER_CYCLE),
+            "61"
+        );
+    }
+
+    #[tokio::test]
+    async fn missing_config_initialization_recheck_preserves_concurrent_config() {
+        let existing = config_with_scanner_cycle("73");
+        let baseline = encode_server_config_blob(&existing, None).expect("existing config should encode");
+        let store = Arc::new(RecoveryMockStore::new(RecoveryReadState::Blob(baseline), None));
+
+        let observed = new_and_save_server_config(store.clone())
+            .await
+            .expect("initialization recheck should return the config created by another writer");
+
+        assert_eq!(store.write_calls.load(Ordering::SeqCst), 0);
+        assert_eq!(
+            observed
+                .get_value(SCANNER_SUB_SYS, DEFAULT_DELIMITER)
+                .expect("concurrent scanner config")
+                .get(SCANNER_CYCLE),
+            "73"
+        );
+    }
+
    #[tokio::test]
    async fn stale_server_config_snapshot_cannot_overwrite_newer_update() {
        let baseline = encode_server_config_blob(&Config::new(), None).expect("baseline config should encode");
@@ -4357,7 +4945,7 @@ mod tests {
        let lock = rustfs_lock::NamespaceLock::new("server-config-lease-loss".to_string(), client.clone());
        let guard = lock
            .lock_guard(
-                rustfs_lock::ObjectKey::new(crate::disk::RUSTFS_META_BUCKET, server_config_path()),
+                rustfs_lock::ObjectKey::new(crate::disk::RUSTFS_META_BUCKET, server_config_transaction_lock_path()),
                "server-config-lease-loss",
                std::time::Duration::from_secs(1),
                std::time::Duration::from_millis(120),
@@ -4372,6 +4960,7 @@ mod tests {
            raw: Some(baseline.clone()),
            seed: None,
            etag: Some("config-0".to_string()),
+            generation: Some(uuid::Uuid::from_u128(1)),
            _local_guard: local_guard,
            _guard: guard,
        };
@@ -37,7 +37,9 @@ use crate::{
    runtime::instance::{InstanceContext, bootstrap_ctx},
    runtime::sources as runtime_sources,
    set_disk::{PreparedGetObjectMetadata, SetDisks},
-    store::init_format::{check_format_erasure_values, get_format_erasure_in_quorum, load_format_erasure_all, save_format_file},
+    store::init_format::{
+        check_format_erasure_values, load_format_erasure_all, save_format_file, select_format_erasure_in_quorum,
+    },
 };
 use futures::{
    future::join_all,
@@ -947,7 +949,7 @@ impl crate::storage_api_contracts::heal::HealOperations for Sets {

    #[tracing::instrument(skip(self))]
    async fn heal_format(&self, dry_run: bool) -> Result<(HealResultItem, Option<Error>)> {
-        let (disks, _) = init_storage_disks_with_errors(
+        let (disks, init_errs) = init_storage_disks_with_errors(
            &self.endpoints.endpoints,
            &DiskOption {
                cleanup: false,
@@ -955,15 +957,36 @@ impl crate::storage_api_contracts::heal::HealOperations for Sets {
            },
        )
        .await;
-        let (formats, errs) = load_format_erasure_all(&disks, true).await;
+        let (formats, mut errs) = load_format_erasure_all(&disks, true).await;
+        for (err, init_err) in errs.iter_mut().zip(init_errs) {
+            if init_err.is_some() {
+                *err = init_err;
+            }
+        }
+        if errs.iter().any(|err| {
+            matches!(
+                err,
+                Some(DiskError::InconsistentDisk | DiskError::CorruptedFormat | DiskError::CorruptedBackend)
+            )
+        }) {
+            return Ok((HealResultItem::default(), Some(StorageError::CorruptedFormat)));
+        }
        if let Err(err) = check_format_erasure_values(&formats, self.set_drive_count) {
            info!("failed to check formats erasure values: {}", err);
            return Ok((HealResultItem::default(), Some(err)));
        }
-        let ref_format = match get_format_erasure_in_quorum(&formats) {
-            Ok(format) => format,
+        let (ref_format, quorum_members) = match select_format_erasure_in_quorum(&formats, 0) {
+            Ok((format, members)) if format.shared_identity() == self.format.shared_identity() => (format, members),
+            Ok(_) => return Ok((HealResultItem::default(), Some(StorageError::CorruptedFormat))),
            Err(err) => return Ok((HealResultItem::default(), Some(err))),
        };
+        if formats
+            .iter()
+            .zip(quorum_members)
+            .any(|(format, member)| format.is_some() && !member)
+        {
+            return Ok((HealResultItem::default(), Some(StorageError::CorruptedFormat)));
+        }
        let mut res = HealResultItem {
            heal_item_type: HealItemType::Metadata.to_string(),
            detail: "disk-format".to_string(),
@@ -985,11 +1008,6 @@ impl crate::storage_api_contracts::heal::HealOperations for Sets {
            return Ok((res, Some(StorageError::NoHealRequired)));
        }

-        // if !self.format.eq(&ref_format) {
-        //     info!("format ({:?}) not eq ref_format ({:?})", self.format, ref_format);
-        //     return Ok((res, Some(Error::new(DiskError::CorruptedFormat))));
-        // }
-
        let (new_format_sets, _) = new_heal_format_sets(&ref_format, self.set_count, self.set_drive_count, &formats, &errs);
        if !dry_run {
            let mut tmp_new_formats = vec![None; self.set_count * self.set_drive_count];
@@ -1298,7 +1316,7 @@ mod tests {
        assert_eq!(result, (Some(3), Some(1), Some(0)));
    }

-    async fn multipart_listing_test_sets() -> (Vec<tempfile::TempDir>, Arc<Sets>) {
+    async fn two_set_test_sets() -> (Vec<tempfile::TempDir>, Arc<Sets>) {
        let format = FormatV3::new(2, 2);
        let mut temp_dirs = Vec::new();
        let mut all_endpoints = Vec::new();
@@ -1339,8 +1357,8 @@ mod tests {
                    Arc::new(RwLock::new(disks)),
                    2,
                    1,
-                    0,
                    set_index,
+                    0,
                    endpoints,
                    format.clone(),
                    vec![Arc::new(LocalClient::new()), Arc::new(LocalClient::new())],
@@ -1373,11 +1391,114 @@ mod tests {
        (temp_dirs, sets)
    }

+    #[tokio::test]
+    async fn set_format_heal_accepts_quorum_from_a_nonzero_set() {
+        let (_temp_dirs, sets) = two_set_test_sets().await;
+
+        let (result, err) = sets.disk_set[1]
+            .heal_format(false)
+            .await
+            .expect("the second erasure set should load its own format quorum");
+
+        assert!(matches!(err, Some(StorageError::NoHealRequired)), "unexpected heal result: {err:?}");
+        assert_eq!(result.disk_count, 2);
+        assert_eq!(result.set_count, 1);
+    }
+
+    #[tokio::test]
+    async fn format_heal_rejects_foreign_majorities_at_set_and_pool_scopes() {
+        let (_temp_dirs, _canonical_format, sets) = setup_heal_format_sets(2, true).await;
+        let set_disks = set_level_heal_view(&sets).await;
+
+        let (_, set_err) = set_disks
+            .heal_format(false)
+            .await
+            .expect("set format heal should report a typed mismatch");
+        assert!(
+            matches!(set_err, Some(StorageError::CorruptedFormat)),
+            "foreign set majority must not replace the cached format: {set_err:?}"
+        );
+
+        let (_, pool_err) = sets
+            .heal_format(false)
+            .await
+            .expect("pool format heal should report a typed mismatch");
+        assert!(
+            matches!(pool_err, Some(StorageError::CorruptedFormat)),
+            "foreign pool majority must not replace the cached format: {pool_err:?}"
+        );
+    }
+
+    #[tokio::test]
+    async fn pool_format_heal_rejects_a_wrong_slot_minority() {
+        let (_temp_dirs, canonical_format, sets) = setup_heal_format_sets(3, false).await;
+        let mut poisoned_format = canonical_format.clone();
+        poisoned_format.erasure.this = canonical_format.erasure.sets[0][0];
+        replace_heal_test_format(&sets, 2, &poisoned_format).await;
+        let probe_err = new_disk(
+            &sets.endpoints.endpoints.as_ref()[2],
+            &DiskOption {
+                cleanup: false,
+                health_check: false,
+            },
+        )
+        .await
+        .expect_err("a wrong-slot local format must fail disk initialization");
+        assert_eq!(probe_err, DiskError::InconsistentDisk);
+
+        let (_, pool_err) = sets
+            .heal_format(false)
+            .await
+            .expect("pool format heal should report a typed slot mismatch");
+        assert!(
+            matches!(pool_err, Some(StorageError::CorruptedFormat)),
+            "a wrong-slot minority must not be reported as no-heal-required: {pool_err:?}"
+        );
+        assert_eq!(
+            read_heal_test_format(&sets, 2).await,
+            poisoned_format,
+            "format heal must not overwrite a wrong-slot disk"
+        );
+    }
+
+    #[tokio::test]
+    async fn format_heal_rejects_a_foreign_minority_at_set_and_pool_scopes() {
+        let (_temp_dirs, canonical_format, sets) = setup_heal_format_sets(3, false).await;
+        let mut poisoned_format = canonical_format.clone();
+        poisoned_format.id = Uuid::new_v4();
+        poisoned_format.erasure.this = poisoned_format.erasure.sets[0][2];
+        replace_heal_test_format(&sets, 2, &poisoned_format).await;
+        let set_disks = set_level_heal_view(&sets).await;
+
+        let (_, set_err) = set_disks
+            .heal_format(false)
+            .await
+            .expect("set format heal should report a typed identity mismatch");
+        assert!(
+            matches!(set_err, Some(StorageError::CorruptedFormat)),
+            "a foreign minority must not be reported as no-heal-required: {set_err:?}"
+        );
+
+        let (_, pool_err) = sets
+            .heal_format(false)
+            .await
+            .expect("pool format heal should report a typed identity mismatch");
+        assert!(
+            matches!(pool_err, Some(StorageError::CorruptedFormat)),
+            "a foreign minority must not be reported as no-heal-required: {pool_err:?}"
+        );
+        assert_eq!(
+            read_heal_test_format(&sets, 2).await,
+            poisoned_format,
+            "format heal must not overwrite a foreign disk"
+        );
+    }
+
    #[tokio::test(flavor = "multi_thread")]
    #[serial]
    async fn list_multipart_uploads_merges_all_sets_without_pagination_loss() {
        let _setup_type_guard = SetupTypeGuard::switch_to(SetupType::Erasure).await;
-        let (_temp_dirs, sets) = multipart_listing_test_sets().await;
+        let (_temp_dirs, sets) = two_set_test_sets().await;
        let bucket = format!("multipart-list-{}", Uuid::new_v4().simple());
        sets.make_bucket(&bucket, &MakeBucketOptions::default())
            .await
@@ -1616,11 +1737,15 @@ mod tests {
    // formatting the first `num_formatted` of them against a shared reference
    // format and leaving the rest unformatted. Returns the live TempDir handles
    // (must be kept alive), the reference format, and the assembled `Sets`.
-    // `disk_set` is intentionally empty: these tests only drive `heal_format`
-    // with `dry_run == true`, which never touches `disk_set`.
-    async fn setup_heal_format_sets(num_formatted: usize) -> (Vec<tempfile::TempDir>, FormatV3, Sets) {
+    // `disk_set` is intentionally empty: these tests only exercise paths that
+    // return before pool-level healing delegates into a set.
+    async fn setup_heal_format_sets(num_formatted: usize, foreign_identity: bool) -> (Vec<tempfile::TempDir>, FormatV3, Sets) {
        const SET_DRIVE_COUNT: usize = 3;
        let ref_format = FormatV3::new(1, SET_DRIVE_COUNT);
+        let mut stored_format = ref_format.clone();
+        if foreign_identity {
+            stored_format.id = Uuid::new_v4();
+        }

        let mut dirs = Vec::with_capacity(SET_DRIVE_COUNT);
        let mut endpoints = Vec::with_capacity(SET_DRIVE_COUNT);
@@ -1645,8 +1770,8 @@ mod tests {
            )
            .await
            .expect("disk should be created");
-            let mut disk_format = ref_format.clone();
-            disk_format.erasure.this = ref_format.erasure.sets[0][i];
+            let mut disk_format = stored_format.clone();
+            disk_format.erasure.this = stored_format.erasure.sets[0][i];
            save_format_file(&Some(disk), &Some(disk_format))
                .await
                .expect("format should be saved");
@@ -1677,6 +1802,60 @@ mod tests {
        (dirs, ref_format, sets)
    }

+    async fn set_level_heal_view(sets: &Sets) -> Arc<SetDisks> {
+        let endpoints = sets.endpoints.endpoints.as_ref().clone();
+        let mut disks = Vec::with_capacity(endpoints.len());
+        for endpoint in &endpoints {
+            disks.push(Some(
+                new_disk(
+                    endpoint,
+                    &DiskOption {
+                        cleanup: false,
+                        health_check: false,
+                    },
+                )
+                .await
+                .expect("fresh set-level disk handle should open"),
+            ));
+        }
+
+        SetDisks::new(
+            "test-owner".to_string(),
+            Arc::new(RwLock::new(disks)),
+            endpoints.len(),
+            1,
+            0,
+            0,
+            endpoints,
+            sets.format.clone(),
+            Vec::new(),
+        )
+        .await
+    }
+
+    async fn replace_heal_test_format(sets: &Sets, disk_index: usize, format: &FormatV3) {
+        let disk = new_disk(
+            &sets.endpoints.endpoints.as_ref()[disk_index],
+            &DiskOption {
+                cleanup: false,
+                health_check: false,
+            },
+        )
+        .await
+        .expect("heal test disk should open");
+        save_format_file(&Some(disk.clone()), &Some(format.clone()))
+            .await
+            .expect("poisoned test format should be written");
+    }
+
+    async fn read_heal_test_format(sets: &Sets, disk_index: usize) -> FormatV3 {
+        let path = std::path::Path::new(&sets.endpoints.endpoints.as_ref()[disk_index].get_file_path())
+            .join(crate::disk::RUSTFS_META_BUCKET)
+            .join(crate::disk::FORMAT_CONFIG_FILE);
+        let data = tokio::fs::read(path).await.expect("test format should be readable");
+        FormatV3::try_from(data.as_slice()).expect("test format should parse")
+    }
+
    // Regression for #956 (NoHealRequired path): with every disk already
    // formatted, `heal_format` reports exactly one drive record per disk
    // (N = set_count * set_drive_count), each carrying a real endpoint. Before
@@ -1685,7 +1864,7 @@ mod tests {
    #[tokio::test]
    #[serial]
    async fn heal_format_no_heal_required_reports_one_record_per_disk() {
-        let (_dirs, _ref_format, sets) = setup_heal_format_sets(3).await;
+        let (_dirs, _ref_format, sets) = setup_heal_format_sets(3, false).await;

        let (res, err) = sets.heal_format(true).await.expect("heal_format should succeed");
        // All disks formatted -> NoHealRequired early return, still returns `res`.
@@ -1715,7 +1894,7 @@ mod tests {
    #[serial]
    async fn heal_format_heal_path_reports_one_record_per_disk_aligned() {
        // Disks 0 and 1 formatted (quorum), disk 2 unformatted.
-        let (_dirs, _ref_format, sets) = setup_heal_format_sets(2).await;
+        let (_dirs, _ref_format, sets) = setup_heal_format_sets(2, false).await;

        let (res, err) = sets.heal_format(true).await.expect("heal_format should succeed");
        // Unformatted disk present -> heal path, not NoHealRequired.
@@ -1049,6 +1049,10 @@ impl LocalDiskWrapper {
        Ok(())
    }

+    pub(crate) async fn set_disk_id_state(&self, id: Option<Uuid>) {
+        *self.disk_id.write().await = id;
+    }
+
    /// Get the current disk ID
    pub async fn get_current_disk_id(&self) -> Option<Uuid> {
        *self.disk_id.read().await
@@ -5078,7 +5078,7 @@ impl LocalDisk {
        Ok((buf, mtime))
    }

-    #[cfg_attr(feature = "hotpath", hotpath::measure)]
+    #[hotpath::measure(impl_type = "LocalDisk")]
    async fn read_metadata_with_dmtime(&self, file_path: impl AsRef<Path>) -> Result<(Vec<u8>, Option<OffsetDateTime>)> {
        check_path_length(file_path.as_ref().to_string_lossy().as_ref())?;

@@ -5121,7 +5121,7 @@ impl LocalDisk {
        Ok((data, modtime))
    }

-    #[cfg_attr(feature = "hotpath", hotpath::measure)]
+    #[hotpath::measure(impl_type = "LocalDisk")]
    async fn read_all_data(&self, volume: &str, volume_dir: impl AsRef<Path>, file_path: impl AsRef<Path>) -> Result<Vec<u8>> {
        // TODO: timeout support
        let (data, _) = self.read_all_data_with_dmtime(volume, volume_dir, file_path).await?;
@@ -6641,6 +6641,49 @@ impl LocalDisk {
        let xl_path = object_dir.join(STORAGE_FORMAT_FILE);
        restore_delete_rollback_after_error(object_dir, &xl_path, Some(rollback_dir), volume, object, stage, err).await
    }
+
+    /// Execute every deferred data-dir deletion pending on `volume` right now,
+    /// even while snapshot leases are still held. Bucket deletion requires it:
+    /// a streaming reader defers the physical cleanup of an already-deleted
+    /// version, and a non-force `delete_volume` would otherwise fail closed
+    /// with `VolumeNotEmpty` on those remnants even though the bucket is
+    /// logically empty. The still-active readers keep their open descriptors;
+    /// only path-based reopens observe the removal.
+    async fn settle_pending_snapshot_deletes(&self, volume: &str) {
+        let pending: Vec<(SnapshotLeaseKey, DeleteOptions)> = {
+            let mut registry = self.snapshot_leases.lock().await;
+            registry
+                .entries
+                .iter_mut()
+                .filter(|(key, entry)| key.volume == volume && !entry.deleting && entry.pending_delete.is_some())
+                .map(|(key, entry)| {
+                    entry.deleting = true;
+                    (key.clone(), entry.pending_delete.clone().expect("filtered on Some"))
+                })
+                .collect()
+        };
+
+        for (key, opts) in pending {
+            let result = self.delete_unleased(&key.volume, &key.path, &opts).await;
+            let mut registry = self.snapshot_leases.lock().await;
+            match result {
+                Ok(()) => {
+                    registry.entries.remove(&key);
+                }
+                Err(err) => {
+                    if let Some(entry) = registry.entries.get_mut(&key) {
+                        entry.deleting = false;
+                    }
+                    warn!(
+                        volume = %key.volume,
+                        path = %key.path,
+                        error = %err,
+                        "failed to settle deferred data-dir deletion before volume removal"
+                    );
+                }
+            }
+        }
+    }
 }

 #[async_trait::async_trait]
@@ -9122,6 +9165,14 @@ impl DiskAPI for LocalDisk {
        let p = self.get_bucket_path(volume)?;
        let _volume_mutation_guard = os::disk_volume_mutation_lock(&self.root, volume).write_owned().await;

+        // A streaming reader's snapshot lease defers the physical cleanup of
+        // data dirs whose version delete already committed. Those remnants are
+        // logically deleted, so run the parked cleanups now instead of letting
+        // the non-force removal below fail closed on them (the s3-tests SSE-C
+        // teardown races exactly this way: DeleteObjects, then DeleteBucket
+        // while an abandoned GET body still pins the lease).
+        self.settle_pending_snapshot_deletes(volume).await;
+
        // Non-force removes empty directory remnants children-first with
        // non-recursive rmdir calls. A file that exists during the scan, or
        // appears before its parent is removed, fails closed with
@@ -15981,6 +16032,74 @@ mod test {
        assert!(matches!(disk.read_all(volume, &first_part).await, Err(DiskError::FileNotFound)));
    }

+    #[tokio::test]
+    async fn delete_volume_settles_lease_deferred_cleanup() {
+        use tempfile::tempdir;
+
+        let root_dir = tempdir().expect("temp dir should be created");
+        let endpoint = Endpoint::try_from(root_dir.path().to_string_lossy().as_ref()).expect("endpoint should parse");
+        let disk = LocalDisk::new(&endpoint, false).await.expect("local disk should be created");
+        let volume = "snapshot-lease-bucket-delete";
+        let object = "multipart_enc";
+        let version_id = Uuid::new_v4();
+        let data_dir = Uuid::new_v4();
+        let rollback_dir = Uuid::new_v4();
+        let data_path = path_join_buf(&[object, &data_dir.to_string()]);
+        let part = path_join_buf(&[&data_path, "part.1"]);
+        ensure_test_volume(&disk, volume).await;
+        disk.write_all(volume, &part, Bytes::from_static(b"payload"))
+            .await
+            .expect("shard should be written");
+        let fi = test_file_info(object, version_id, Some(data_dir), None);
+        disk.write_all(volume, &path_join_buf(&[object, STORAGE_FORMAT_FILE]), test_meta(fi.clone()).into())
+            .await
+            .expect("metadata should be written");
+
+        // An abandoned streaming GET pins the data dir with a snapshot lease.
+        let snapshot = disk
+            .acquire_snapshot_lease(volume, &data_path)
+            .await
+            .expect("snapshot lease should be acquired");
+        disk.delete_version(
+            volume,
+            object,
+            fi.clone(),
+            false,
+            DeleteOptions {
+                old_data_dir: Some(rollback_dir),
+                ..Default::default()
+            },
+        )
+        .await
+        .expect("version delete should commit metadata");
+        disk.delete(
+            volume,
+            &format!("{object}/{rollback_dir}"),
+            DeleteOptions {
+                recursive: true,
+                immediate: true,
+                ..Default::default()
+            },
+        )
+        .await
+        .expect("version delete should schedule physical cleanup");
+
+        // The bucket is logically empty; a non-force volume delete must settle
+        // the deferred data-dir cleanup instead of failing with VolumeNotEmpty.
+        disk.delete_volume(volume, false)
+            .await
+            .expect("bucket delete must not observe lease-deferred remnants");
+        assert!(matches!(
+            disk.read_all(volume, &part).await,
+            Err(DiskError::FileNotFound | DiskError::VolumeNotFound)
+        ));
+
+        // The late lease release finds nothing pending and stays idempotent.
+        disk.release_snapshot_lease(volume, &data_path, snapshot)
+            .await
+            .expect("releasing the lease after bucket deletion should be a no-op");
+    }
+
    #[tokio::test]
    async fn version_delete_cleanup_intent_survives_local_disk_restart() {
        use tempfile::tempdir;
@@ -132,6 +132,18 @@ pub enum Disk {
    Remote(Box<RemoteDisk>),
 }

+impl Disk {
+    pub(crate) async fn set_disk_id_state(&self, id: Option<Uuid>) -> Result<()> {
+        match self {
+            Disk::Local(local_disk) => {
+                local_disk.set_disk_id_state(id).await;
+                Ok(())
+            }
+            Disk::Remote(remote_disk) => remote_disk.set_disk_id(id).await,
+        }
+    }
+}
+
 #[async_trait::async_trait]
 impl DiskAPI for Disk {
    fn to_string(&self) -> String {
@@ -1552,6 +1564,72 @@ mod tests {
        let _ = fs::remove_dir_all(&test_dir).await;
    }

+    #[tokio::test]
+    #[serial_test::serial]
+    async fn local_disk_id_state_does_not_publish_to_the_process_registry() {
+        let local_dir = tempfile::tempdir().expect("local disk tempdir should be created");
+        let mut endpoint =
+            Endpoint::try_from(local_dir.path().to_str().expect("tempdir path should be utf8")).expect("endpoint should parse");
+        endpoint.set_pool_index(0);
+        endpoint.set_set_index(0);
+        endpoint.set_disk_index(0);
+        let local_disk = LocalDisk::new(&endpoint, false).await.expect("local disk should initialize");
+        let disk = Disk::Local(Box::new(LocalDiskWrapper::new(Arc::new(local_disk), false)));
+        let disk_id = Uuid::new_v4();
+
+        disk.set_disk_id_state(Some(disk_id))
+            .await
+            .expect("local wrapper state should accept a disk ID");
+
+        let Disk::Local(local_disk) = &disk else {
+            panic!("test disk should remain local");
+        };
+        assert_eq!(local_disk.get_current_disk_id().await, Some(disk_id));
+        assert!(
+            !crate::runtime::global::current_ctx()
+                .local_disk_id_map()
+                .read()
+                .await
+                .contains_key(&disk_id),
+            "state-only startup publication must not update the process disk-ID registry"
+        );
+
+        disk.set_disk_id_state(None)
+            .await
+            .expect("local wrapper state should clear a disk ID");
+        assert_eq!(local_disk.get_current_disk_id().await, None);
+    }
+
+    #[tokio::test]
+    async fn remote_disk_id_state_delegates_some_and_none() {
+        let mut endpoint = Endpoint::try_from("http://remote-server:9000/data").expect("remote endpoint should parse");
+        endpoint.set_pool_index(0);
+        endpoint.set_set_index(0);
+        endpoint.set_disk_index(0);
+        let remote_disk = RemoteDisk::new(
+            &endpoint,
+            &DiskOption {
+                cleanup: false,
+                health_check: false,
+            },
+            Arc::new(crate::cluster::rpc::TcpHttpInternodeDataTransport),
+        )
+        .await
+        .expect("remote disk should initialize");
+        let disk = Disk::Remote(Box::new(remote_disk));
+        let disk_id = Uuid::new_v4();
+
+        disk.set_disk_id_state(Some(disk_id))
+            .await
+            .expect("remote state should accept a disk ID");
+        assert_eq!(disk.get_disk_id().await.expect("remote disk ID should be readable"), Some(disk_id));
+
+        disk.set_disk_id_state(None)
+            .await
+            .expect("remote state should clear a disk ID");
+        assert_eq!(disk.get_disk_id().await.expect("remote disk ID should be readable"), None);
+    }
+
    #[tokio::test]
    async fn reset_health_for_store_init_retry_delegates_to_disk_variants() {
        let local_dir = tempfile::tempdir().unwrap();
@@ -103,7 +103,7 @@ where
    /// or `out` is larger than one shard. On error `out`'s contents are
    /// unspecified but never contain bytes that failed the hash check — the copy
    /// happens only after verification.
-    #[cfg_attr(feature = "hotpath", hotpath::measure)]
+    #[hotpath::measure(impl_type = "BitrotReader")]
    pub async fn read(&mut self, out: &mut [u8]) -> std::io::Result<usize> {
        let want = out.len();
        self.begin_read(want)?;
@@ -303,7 +303,7 @@ where

    /// Write a (hash+data) block. Returns the number of data bytes written.
    /// Returns an error if called after a short write or if data exceeds shard_size.
-    #[cfg_attr(feature = "hotpath", hotpath::measure(label = "BitrotWriter::write"))]
+    #[hotpath::measure(label = "BitrotWriter::write", impl_type = "BitrotWriter")]
    pub async fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
        if buf.is_empty() {
            return Ok(0);
@@ -455,7 +455,7 @@ pub fn bitrot_shard_file_size(size: usize, shard_size: usize, algo: HashAlgorith
 /// stores those as whole-file bitrot with no interleaved hash, so the size guard
 /// on the next line would reject a genuinely healthy part. Reading legacy V1
 /// whole-file-bitrot objects would need a separate verification path.
-#[cfg_attr(feature = "hotpath", hotpath::measure)]
+#[hotpath::measure]
 pub async fn bitrot_verify<R: AsyncRead + Unpin + Send>(
    mut r: R,
    want_size: usize,
@@ -691,7 +691,7 @@ impl<R> ParallelReader<R>
 where
    R: crate::erasure::coding::ShardSource,
 {
-    #[cfg_attr(feature = "hotpath", hotpath::measure)]
+    #[hotpath::measure(impl_type = "ParallelReader")]
    pub async fn read(&mut self) -> (Vec<Option<Vec<u8>>>, Vec<Option<Error>>) {
        // On the reconstruction-verifying GET path, read every live shard reader
        // in lockstep so all readers advance one block per stripe and stay
@@ -1505,7 +1505,7 @@ where
 }

 impl Erasure {
-    #[cfg_attr(feature = "hotpath", hotpath::measure)]
+    #[hotpath::measure(impl_type = "Erasure")]
    pub async fn decode<W, R>(
        &self,
        writer: &mut W,
@@ -1645,15 +1645,28 @@ impl Erasure {
            }
            Err(e) => {
                record_get_stage_duration_if_enabled(GET_OBJECT_PATH_LEGACY_DUPLEX, GET_STAGE_EMIT, emit_stage_start);
-                error!(
-                    block_offset,
-                    block_length,
-                    bytes_written = *written,
-                    stage = GET_STAGE_EMIT,
-                    reason = classify_io_error(&e).as_str(),
-                    error = ?e,
-                    "Erasure decode failed to emit reconstructed data"
-                );
+                let reason = classify_io_error(&e);
+                if reason == GetObjectFailureReason::DownstreamClosed {
+                    debug!(
+                        block_offset,
+                        block_length,
+                        bytes_written = *written,
+                        stage = GET_STAGE_EMIT,
+                        reason = reason.as_str(),
+                        error = ?e,
+                        "Erasure decode stopped after downstream closed"
+                    );
+                } else {
+                    error!(
+                        block_offset,
+                        block_length,
+                        bytes_written = *written,
+                        stage = GET_STAGE_EMIT,
+                        reason = reason.as_str(),
+                        error = ?e,
+                        "Erasure decode failed to emit reconstructed data"
+                    );
+                }
                *ret_err = Some(e);
                return StripeFlow::Stop;
            }
@@ -1945,7 +1958,7 @@ mod tests {
    use std::io::Cursor;
    use std::pin::Pin;
    use std::sync::{
-        Arc,
+        Arc, Mutex,
        atomic::{AtomicUsize, Ordering},
    };
    use std::task::{Context, Poll};
@@ -2120,6 +2133,59 @@ mod tests {
        }
    }

+    struct DownstreamClosedWriter;
+
+    impl AsyncWrite for DownstreamClosedWriter {
+        fn poll_write(self: Pin<&mut Self>, _cx: &mut Context<'_>, _buf: &[u8]) -> Poll<io::Result<usize>> {
+            Poll::Ready(Err(crate::diagnostics::get::mark_get_object_downstream_closed(io::Error::new(
+                ErrorKind::BrokenPipe,
+                "injected downstream close",
+            ))))
+        }
+
+        fn poll_flush(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+            Poll::Ready(Ok(()))
+        }
+
+        fn poll_shutdown(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+            Poll::Ready(Ok(()))
+        }
+    }
+
+    #[derive(Clone, Default)]
+    struct CapturedLogs(Arc<Mutex<Vec<u8>>>);
+
+    struct CapturedLogWriter(Arc<Mutex<Vec<u8>>>);
+
+    impl CapturedLogs {
+        fn contents(&self) -> String {
+            String::from_utf8(self.0.lock().expect("captured logs mutex should not be poisoned").clone())
+                .expect("captured logs should be valid UTF-8")
+        }
+    }
+
+    impl std::io::Write for CapturedLogWriter {
+        fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
+            self.0
+                .lock()
+                .expect("captured logs mutex should not be poisoned")
+                .extend_from_slice(buf);
+            Ok(buf.len())
+        }
+
+        fn flush(&mut self) -> std::io::Result<()> {
+            Ok(())
+        }
+    }
+
+    impl<'a> tracing_subscriber::fmt::MakeWriter<'a> for CapturedLogs {
+        type Writer = CapturedLogWriter;
+
+        fn make_writer(&'a self) -> Self::Writer {
+            CapturedLogWriter(Arc::clone(&self.0))
+        }
+    }
+
    #[test]
    fn parallel_reader_constructor_variants_preserve_read_cost_and_verification_flags() {
        let erasure = Erasure::new(2, 1, 64);
@@ -2215,6 +2281,47 @@ mod tests {
        assert_eq!(err.to_string(), "injected emit failure");
    }

+    #[tokio::test(flavor = "current_thread")]
+    async fn erasure_decode_logs_reconstructed_downstream_close_at_debug() {
+        let logs = CapturedLogs::default();
+        let subscriber = tracing_subscriber::fmt()
+            .with_max_level(tracing::Level::DEBUG)
+            .with_writer(logs.clone())
+            .with_ansi(false)
+            .without_time()
+            .finish();
+        let _guard = tracing::subscriber::set_default(subscriber);
+
+        let erasure = Erasure::new(2, 1, 64);
+        let data: Vec<u8> = (0..64).collect();
+        let shard_size = erasure.shard_size();
+        let encoded = erasure.encode_data(&data).expect("test data should encode");
+        let readers = vec![
+            None,
+            Some(BitrotReader::new(
+                Cursor::new(encoded[1].to_vec()),
+                shard_size,
+                HashAlgorithm::None,
+                false,
+            )),
+            Some(BitrotReader::new(
+                Cursor::new(encoded[2].to_vec()),
+                shard_size,
+                HashAlgorithm::None,
+                false,
+            )),
+        ];
+
+        let mut writer = DownstreamClosedWriter;
+        let (written, err) = erasure.decode(&mut writer, readers, 0, data.len(), data.len()).await;
+
+        assert_eq!(written, 0);
+        assert_eq!(err.expect("downstream close must still terminate the GET").kind(), ErrorKind::BrokenPipe);
+        let captured = logs.contents();
+        assert!(captured.contains("Erasure decode stopped after downstream closed"));
+        assert!(!captured.contains("Erasure decode failed to emit reconstructed data"));
+    }
+
    #[tokio::test]
    async fn test_erasure_decode_rejects_reader_count_and_range_overflow() {
        let erasure = Erasure::new(2, 1, 64);
@@ -28,8 +28,11 @@ use std::vec;
 use tokio::io::AsyncRead;
 use tokio::runtime::RuntimeFlavor;
 use tokio::sync::mpsc;
+use tokio::task::{JoinError, JoinHandle};
 use tracing::error;

+/// Queue-capacity input for encoded blocks awaiting shard writers; it is not a
+/// per-PUT or process-RSS memory limit.
 const ENV_RUSTFS_ERASURE_ENCODE_MAX_INFLIGHT_BYTES: &str = "RUSTFS_ERASURE_ENCODE_MAX_INFLIGHT_BYTES";
 const ENV_RUSTFS_ERASURE_ENCODE_BATCH_BLOCKS: &str = "RUSTFS_ERASURE_ENCODE_BATCH_BLOCKS";
 const ENV_RUSTFS_ERASURE_ENCODE_BYTESMUT_INGEST: &str = "RUSTFS_ERASURE_ENCODE_BYTESMUT_INGEST";
@@ -87,6 +90,33 @@ fn use_bytesmut_ingest() -> bool {
        rustfs_utils::get_env_bool(ENV_RUSTFS_ERASURE_ENCODE_BYTESMUT_INGEST, DEFAULT_RUSTFS_ERASURE_ENCODE_BYTESMUT_INGEST)
    })
 }
+
+/// Keeps the encoder producer scoped to its parent future. Tokio detaches a
+/// task when its `JoinHandle` is dropped, so the producer must be aborted when
+/// an upload is cancelled before the encode pipeline finishes.
+struct AbortOnDropTask<T>(JoinHandle<T>);
+
+impl<T> AbortOnDropTask<T> {
+    fn new(task: JoinHandle<T>) -> Self {
+        Self(task)
+    }
+
+    async fn abort_and_wait(&mut self) {
+        self.0.abort();
+        let _ = (&mut self.0).await;
+    }
+
+    async fn join(&mut self) -> Result<T, JoinError> {
+        (&mut self.0).await
+    }
+}
+
+impl<T> Drop for AbortOnDropTask<T> {
+    fn drop(&mut self) {
+        self.0.abort();
+    }
+}
+
 /// Read up to `limit` bytes into `buf`'s uninitialized spare capacity, appending after its
 /// current length, and distinguish a clean EOF from a short read.
 ///
@@ -133,22 +163,65 @@ fn queued_block_bytes(block: &[Bytes]) -> usize {
    block.iter().map(Bytes::len).sum()
 }

-async fn drain_queued_inflight_bytes(rx: &mut mpsc::Receiver<Vec<Bytes>>) {
-    while let Some(block) = rx.recv().await {
-        rustfs_io_metrics::remove_ec_encode_inflight_bytes(queued_block_bytes(&block));
+/// Owns an encoded queue entry's gauge contribution until its consumer takes it.
+struct QueuedInflightBytes {
+    bytes: usize,
+}
+
+impl QueuedInflightBytes {
+    fn new(bytes: usize) -> Self {
+        rustfs_io_metrics::add_ec_encode_inflight_bytes(bytes);
+        Self { bytes }
    }
+
+    fn settle(&mut self) {
+        let bytes = std::mem::take(&mut self.bytes);
+        if bytes != 0 {
+            rustfs_io_metrics::remove_ec_encode_inflight_bytes(bytes);
+        }
+    }
+}
+
+impl Drop for QueuedInflightBytes {
+    fn drop(&mut self) {
+        self.settle();
+    }
+}
+
+/// Couples an encoded block with its queue gauge contribution. Keeping the
+/// guard in the queue entry also covers Tokio sends that complete through a
+/// permit after the receiver has closed.
+struct InflightEntry<T> {
+    entry: T,
+    accounting: QueuedInflightBytes,
+}
+
+impl<T> InflightEntry<T> {
+    fn new(entry: T, bytes: usize) -> Self {
+        Self {
+            entry,
+            accounting: QueuedInflightBytes::new(bytes),
+        }
+    }
+
+    fn into_inner(mut self) -> T {
+        self.accounting.settle();
+        self.entry
+    }
+}
+
+async fn send_queued<T>(
+    sender: &mpsc::Sender<InflightEntry<T>>,
+    entry: T,
+    bytes: usize,
+) -> Result<(), mpsc::error::SendError<InflightEntry<T>>> {
+    sender.send(InflightEntry::new(entry, bytes)).await
 }

 fn queued_batch_bytes(batch: &[Vec<Bytes>]) -> usize {
    batch.iter().map(|block| queued_block_bytes(block)).sum()
 }

-async fn drain_queued_batched_inflight_bytes(rx: &mut mpsc::Receiver<Vec<Vec<Bytes>>>) {
-    while let Some(batch) = rx.recv().await {
-        rustfs_io_metrics::remove_ec_encode_inflight_bytes(queued_batch_bytes(&batch));
-    }
-}
-
 fn dominant_error_summary_label(summary: &WriteQuorumFailureSummary) -> &'static str {
    summary.dominant_error_label
 }
@@ -504,7 +577,7 @@ impl Erasure {
        Ok((reader, total))
    }

-    #[cfg_attr(feature = "hotpath", hotpath::measure)]
+    #[hotpath::measure(impl_type = "Erasure")]
    pub async fn encode<R>(
        self: Arc<Self>,
        reader: R,
@@ -540,13 +613,14 @@ impl Erasure {
            ));
        }

-        // Bound queued encoded blocks by memory budget to avoid per-request spikes.
+        // Bound queued encoded blocks by a queue budget; this does not bound
+        // reader, encoder, writer, allocator, or process-RSS memory.
        let expanded_block_bytes = self.shard_size().saturating_mul(self.total_shard_count());
        let max_inflight_bytes = erasure_encode_max_inflight_bytes();
        let inflight_blocks = encode_channel_capacity(expanded_block_bytes, max_inflight_bytes);
-        let (tx, mut rx) = mpsc::channel::<Vec<Bytes>>(inflight_blocks);
+        let (tx, mut rx) = mpsc::channel::<InflightEntry<Vec<Bytes>>>(inflight_blocks);

-        let task = tokio::spawn(async move {
+        let mut task = AbortOnDropTask::new(tokio::spawn(async move {
            let block_size = self.block_size;
            let mut total = 0;
            if use_bytesmut_ingest {
@@ -567,10 +641,9 @@ impl Erasure {
                            let res = self.clone().encode_block_bytes_mut(encode_buf, n).await?;
                            buf = BytesMut::with_capacity(ingest_capacity);
                            let queued_bytes = queued_block_bytes(&res);
-                            rustfs_io_metrics::add_ec_encode_inflight_bytes(queued_bytes);
+                            let _producer_stage = rustfs_io_metrics::track_ec_encode_producer_bytes(queued_bytes);
                            let send_wait_stage_start = stage_timer_if_enabled();
-                            if let Err(err) = tx.send(res).await {
-                                rustfs_io_metrics::remove_ec_encode_inflight_bytes(queued_bytes);
+                            if let Err(err) = send_queued(&tx, res, queued_bytes).await {
                                return Err(std::io::Error::other(format!("Failed to send encoded data : {err}")));
                            }
                            record_internal_stage_if_enabled("erasure_encode_send_wait", send_wait_stage_start);
@@ -598,10 +671,9 @@ impl Erasure {
                            let (res, returned_buf) = self.clone().encode_block(encode_buf, n).await?;
                            buf = returned_buf;
                            let queued_bytes = queued_block_bytes(&res);
-                            rustfs_io_metrics::add_ec_encode_inflight_bytes(queued_bytes);
+                            let _producer_stage = rustfs_io_metrics::track_ec_encode_producer_bytes(queued_bytes);
                            let send_wait_stage_start = stage_timer_if_enabled();
-                            if let Err(err) = tx.send(res).await {
-                                rustfs_io_metrics::remove_ec_encode_inflight_bytes(queued_bytes);
+                            if let Err(err) = send_queued(&tx, res, queued_bytes).await {
                                return Err(std::io::Error::other(format!("Failed to send encoded data : {err}")));
                            }
                            record_internal_stage_if_enabled("erasure_encode_send_wait", send_wait_stage_start);
@@ -626,7 +698,7 @@ impl Erasure {
            }

            Ok((reader, total))
-        });
+        }));

        let mut writers = MultiWriter::new(writers, quorum);

@@ -638,11 +710,11 @@ impl Erasure {
                break;
            };
            record_internal_stage_if_enabled("erasure_encode_recv_wait", recv_wait_stage_start);
+            let block = block.into_inner();
            if block.is_empty() {
                break;
            }
-            let queued_bytes = queued_block_bytes(&block);
-            rustfs_io_metrics::remove_ec_encode_inflight_bytes(queued_bytes);
+            let _writer_stage = rustfs_io_metrics::track_ec_encode_writer_bytes(queued_block_bytes(&block));
            let write_stage_start = stage_timer_if_enabled();
            if let Err(err) = writers.write(block).await {
                write_err = Some(err);
@@ -652,9 +724,8 @@ impl Erasure {
        }

        if let Some(err) = write_err {
-            task.abort();
-            let _ = task.await;
-            drain_queued_inflight_bytes(&mut rx).await;
+            task.abort_and_wait().await;
+            drop(rx);
            let shutdown_stage_start = stage_timer_if_enabled();
            if let Err(shutdown_err) = writers.shutdown().await {
                error!("failed to shutdown erasure writers after write error: {:?}", shutdown_err);
@@ -663,14 +734,14 @@ impl Erasure {
            return Err(err);
        }

-        let (reader, total) = task.await??;
+        let (reader, total) = task.join().await??;
        let shutdown_stage_start = stage_timer_if_enabled();
        writers.shutdown().await?;
        record_internal_stage_if_enabled("erasure_encode_shutdown", shutdown_stage_start);
        Ok((reader, total))
    }

-    #[cfg_attr(feature = "hotpath", hotpath::measure)]
+    #[hotpath::measure(impl_type = "Erasure")]
    pub async fn encode_batched<R>(
        self: Arc<Self>,
        mut reader: R,
@@ -692,14 +763,15 @@ impl Erasure {
        let inflight_blocks = encode_channel_capacity(expanded_block_bytes, max_inflight_bytes);
        let batch_blocks = encode_batch_block_count().min(inflight_blocks);
        let channel_capacity = inflight_blocks.div_ceil(batch_blocks).max(1);
-        let (tx, mut rx) = mpsc::channel::<Vec<Vec<Bytes>>>(channel_capacity);
+        let (tx, mut rx) = mpsc::channel::<InflightEntry<Vec<Vec<Bytes>>>>(channel_capacity);

-        let task = tokio::spawn(async move {
+        let mut task = AbortOnDropTask::new(tokio::spawn(async move {
            let block_size = self.block_size;
            let mut total = 0;
            let mut buf = vec![0u8; block_size];
            let mut pending_batch = Vec::with_capacity(batch_blocks);
            let mut pending_batch_bytes = 0usize;
+            let mut pending_batch_stage = None;
            loop {
                match rustfs_utils::read_full_or_eof(&mut reader, &mut buf).await {
                    Ok(Some(n)) => {
@@ -711,15 +783,16 @@ impl Erasure {
                        let queued_bytes = queued_block_bytes(&res);
                        pending_batch_bytes = pending_batch_bytes.saturating_add(queued_bytes);
                        pending_batch.push(res);
+                        drop(pending_batch_stage.take());
+                        pending_batch_stage = Some(rustfs_io_metrics::track_ec_encode_producer_bytes(pending_batch_bytes));

                        if pending_batch.len() >= batch_blocks {
-                            rustfs_io_metrics::add_ec_encode_inflight_bytes(pending_batch_bytes);
                            let send_wait_stage_start = stage_timer_if_enabled();
-                            if let Err(err) = tx.send(pending_batch).await {
-                                rustfs_io_metrics::remove_ec_encode_inflight_bytes(pending_batch_bytes);
+                            if let Err(err) = send_queued(&tx, pending_batch, pending_batch_bytes).await {
                                return Err(std::io::Error::other(format!("Failed to send encoded data : {err}")));
                            }
                            record_internal_stage_if_enabled("erasure_encode_batched_send_wait", send_wait_stage_start);
+                            drop(pending_batch_stage.take());
                            pending_batch = Vec::with_capacity(batch_blocks);
                            pending_batch_bytes = 0;
                        }
@@ -742,17 +815,16 @@ impl Erasure {
            }

            if !pending_batch.is_empty() {
-                rustfs_io_metrics::add_ec_encode_inflight_bytes(pending_batch_bytes);
                let send_wait_stage_start = stage_timer_if_enabled();
-                if let Err(err) = tx.send(pending_batch).await {
-                    rustfs_io_metrics::remove_ec_encode_inflight_bytes(pending_batch_bytes);
+                if let Err(err) = send_queued(&tx, pending_batch, pending_batch_bytes).await {
                    return Err(std::io::Error::other(format!("Failed to send encoded data : {err}")));
                }
                record_internal_stage_if_enabled("erasure_encode_batched_send_wait", send_wait_stage_start);
+                drop(pending_batch_stage);
            }

            Ok((reader, total))
-        });
+        }));

        let mut writers = MultiWriter::new(writers, quorum);
        let mut write_err = None;
@@ -763,7 +835,8 @@ impl Erasure {
                break;
            };
            record_internal_stage_if_enabled("erasure_encode_batched_recv_wait", recv_wait_stage_start);
-            rustfs_io_metrics::remove_ec_encode_inflight_bytes(queued_batch_bytes(&batch));
+            let batch = batch.into_inner();
+            let _writer_stage = rustfs_io_metrics::track_ec_encode_writer_bytes(queued_batch_bytes(&batch));
            let write_stage_start = stage_timer_if_enabled();
            for block in batch {
                if let Err(err) = writers.write(block).await {
@@ -778,9 +851,8 @@ impl Erasure {
        }

        if let Some(err) = write_err {
-            task.abort();
-            let _ = task.await;
-            drain_queued_batched_inflight_bytes(&mut rx).await;
+            task.abort_and_wait().await;
+            drop(rx);
            let shutdown_stage_start = stage_timer_if_enabled();
            if let Err(shutdown_err) = writers.shutdown().await {
                error!("failed to shutdown erasure writers after write error: {:?}", shutdown_err);
@@ -789,7 +861,7 @@ impl Erasure {
            return Err(err);
        }

-        let (reader, total) = task.await??;
+        let (reader, total) = task.join().await??;
        let shutdown_stage_start = stage_timer_if_enabled();
        writers.shutdown().await?;
        record_internal_stage_if_enabled("erasure_encode_batched_shutdown", shutdown_stage_start);
@@ -798,7 +870,7 @@ impl Erasure {

    /// Fast path for small inline objects: skip tokio::spawn + mpsc channel.
    /// Reads all data, encodes directly, writes shards sequentially.
-    #[cfg_attr(feature = "hotpath", hotpath::measure)]
+    #[hotpath::measure(impl_type = "Erasure")]
    pub async fn encode_inline_small<R>(
        self: Arc<Self>,
        reader: R,
@@ -813,7 +885,7 @@ impl Erasure {

    /// Fast path for single-block non-inline objects: avoids the producer/consumer
    /// pipeline in `encode()` while keeping the same writer/quorum/shutdown semantics.
-    #[cfg_attr(feature = "hotpath", hotpath::measure)]
+    #[hotpath::measure(impl_type = "Erasure")]
    pub async fn encode_single_block_non_inline<R>(
        self: Arc<Self>,
        reader: R,
@@ -839,7 +911,104 @@ mod tests {
    use std::sync::{Arc, Mutex};
    use std::task::{Context, Poll};
    use std::time::Duration;
-    use tokio::io::{AsyncWrite, AsyncWriteExt};
+    use tokio::io::{AsyncWrite, AsyncWriteExt, ReadBuf};
+    use tokio::sync::oneshot;
+
+    struct PendingReader {
+        entered: Option<oneshot::Sender<()>>,
+        dropped: Option<oneshot::Sender<()>>,
+    }
+
+    impl PendingReader {
+        fn new() -> (Self, oneshot::Receiver<()>, oneshot::Receiver<()>) {
+            let (entered_tx, entered_rx) = oneshot::channel();
+            let (dropped_tx, dropped_rx) = oneshot::channel();
+            (
+                Self {
+                    entered: Some(entered_tx),
+                    dropped: Some(dropped_tx),
+                },
+                entered_rx,
+                dropped_rx,
+            )
+        }
+    }
+
+    impl AsyncRead for PendingReader {
+        fn poll_read(mut self: Pin<&mut Self>, _cx: &mut Context<'_>, _buf: &mut ReadBuf<'_>) -> Poll<std::io::Result<()>> {
+            if let Some(entered) = self.entered.take() {
+                let _ = entered.send(());
+            }
+            Poll::Pending
+        }
+    }
+
+    impl Drop for PendingReader {
+        fn drop(&mut self) {
+            if let Some(dropped) = self.dropped.take() {
+                let _ = dropped.send(());
+            }
+        }
+    }
+
+    struct BlocksThenPendingReader {
+        blocks_remaining: usize,
+        block: Vec<u8>,
+        blocked: Option<oneshot::Sender<()>>,
+        dropped: Option<oneshot::Sender<()>>,
+        final_block: Option<oneshot::Sender<()>>,
+    }
+
+    impl BlocksThenPendingReader {
+        fn new(
+            blocks_remaining: usize,
+            block_size: usize,
+        ) -> (Self, oneshot::Receiver<()>, oneshot::Receiver<()>, oneshot::Receiver<()>) {
+            let (blocked_tx, blocked_rx) = oneshot::channel();
+            let (dropped_tx, dropped_rx) = oneshot::channel();
+            let (final_block_tx, final_block_rx) = oneshot::channel();
+            (
+                Self {
+                    blocks_remaining,
+                    block: vec![0x5a; block_size],
+                    blocked: Some(blocked_tx),
+                    dropped: Some(dropped_tx),
+                    final_block: Some(final_block_tx),
+                },
+                blocked_rx,
+                dropped_rx,
+                final_block_rx,
+            )
+        }
+    }
+
+    impl AsyncRead for BlocksThenPendingReader {
+        fn poll_read(mut self: Pin<&mut Self>, _cx: &mut Context<'_>, buf: &mut ReadBuf<'_>) -> Poll<std::io::Result<()>> {
+            if self.blocks_remaining == 0 {
+                if let Some(blocked) = self.blocked.take() {
+                    let _ = blocked.send(());
+                }
+                return Poll::Pending;
+            }
+
+            if self.blocks_remaining == 1
+                && let Some(final_block) = self.final_block.take()
+            {
+                let _ = final_block.send(());
+            }
+            self.blocks_remaining -= 1;
+            buf.put_slice(&self.block);
+            Poll::Ready(Ok(()))
+        }
+    }
+
+    impl Drop for BlocksThenPendingReader {
+        fn drop(&mut self) {
+            if let Some(dropped) = self.dropped.take() {
+                let _ = dropped.send(());
+            }
+        }
+    }

    fn erasure_with_zero_block_size() -> Erasure {
        let mut erasure = Erasure::default();
@@ -897,6 +1066,54 @@ mod tests {
        }
    }

+    struct FailAfterReaderBlocksWriter {
+        reader_blocked: oneshot::Receiver<()>,
+        writes: Arc<std::sync::atomic::AtomicUsize>,
+    }
+
+    impl AsyncWrite for FailAfterReaderBlocksWriter {
+        fn poll_write(mut self: Pin<&mut Self>, cx: &mut Context<'_>, _buf: &[u8]) -> Poll<std::io::Result<usize>> {
+            match Pin::new(&mut self.reader_blocked).poll(cx) {
+                Poll::Pending => Poll::Pending,
+                Poll::Ready(_) => {
+                    self.writes.fetch_add(1, std::sync::atomic::Ordering::SeqCst);
+                    Poll::Ready(Err(std::io::Error::other("injected write failure after producer blocks")))
+                }
+            }
+        }
+
+        fn poll_flush(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<std::io::Result<()>> {
+            Poll::Ready(Ok(()))
+        }
+
+        fn poll_shutdown(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<std::io::Result<()>> {
+            Poll::Ready(Ok(()))
+        }
+    }
+
+    struct StallOnWriteWithSignal {
+        entered: Option<oneshot::Sender<()>>,
+        writes: Arc<std::sync::atomic::AtomicUsize>,
+    }
+
+    impl AsyncWrite for StallOnWriteWithSignal {
+        fn poll_write(mut self: Pin<&mut Self>, _cx: &mut Context<'_>, _buf: &[u8]) -> Poll<std::io::Result<usize>> {
+            self.writes.fetch_add(1, std::sync::atomic::Ordering::SeqCst);
+            if let Some(entered) = self.entered.take() {
+                let _ = entered.send(());
+            }
+            Poll::Pending
+        }
+
+        fn poll_flush(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<std::io::Result<()>> {
+            Poll::Ready(Ok(()))
+        }
+
+        fn poll_shutdown(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<std::io::Result<()>> {
+            Poll::Ready(Ok(()))
+        }
+    }
+
    #[derive(Clone, Default)]
    struct ShortWriteWriter;

@@ -1046,6 +1263,262 @@ mod tests {
        BitrotWriterWrapper::new(CustomWriter::new_tokio_writer(writer), shard_size, HashAlgorithm::None)
    }

+    #[derive(Clone, Copy)]
+    enum EncodePipeline {
+        Vec,
+        BytesMut,
+        Batched,
+    }
+
+    async fn aborting_encode_drops_blocked_producer(pipeline: EncodePipeline) {
+        const BLOCK_SIZE: usize = 16;
+
+        let gauge_baseline = rustfs_io_metrics::current_ec_encode_inflight_bytes();
+        let committed = Arc::new(Mutex::new(Vec::new()));
+        let mut writers = vec![Some(bitrot_writer(DeferredCommitWriter::new(committed.clone()), BLOCK_SIZE))];
+        let (reader, entered, dropped) = PendingReader::new();
+        let erasure = Arc::new(Erasure::new(1, 0, BLOCK_SIZE));
+
+        let encode = match pipeline {
+            EncodePipeline::Vec => {
+                tokio::spawn(async move { erasure.encode_with_ingest_mode(reader, &mut writers, 1, false).await })
+            }
+            EncodePipeline::BytesMut => {
+                tokio::spawn(async move { erasure.encode_with_ingest_mode(reader, &mut writers, 1, true).await })
+            }
+            EncodePipeline::Batched => tokio::spawn(async move { erasure.encode_batched(reader, &mut writers, 1).await }),
+        };
+
+        tokio::time::timeout(Duration::from_secs(1), entered)
+            .await
+            .expect("producer should enter the blocked reader before cancellation")
+            .expect("blocked reader should signal entry");
+        encode.abort();
+        assert!(matches!(encode.await, Err(err) if err.is_cancelled()), "encode task should be cancelled");
+        tokio::time::timeout(Duration::from_secs(1), dropped)
+            .await
+            .expect("cancelling encode should drop the producer reader")
+            .expect("blocked reader should signal producer drop");
+        assert!(
+            committed.lock().expect("committed buffer should be lockable").is_empty(),
+            "cancelling before the first encoded block must not make data visible"
+        );
+        assert_eq!(
+            rustfs_io_metrics::current_ec_encode_inflight_bytes(),
+            gauge_baseline,
+            "cancelling the encode pipeline must preserve the inflight queue gauge"
+        );
+    }
+
+    async fn writer_error_aborts_blocked_producer(pipeline: EncodePipeline) {
+        let gauge_baseline = rustfs_io_metrics::current_ec_encode_inflight_bytes();
+        let producer_baseline = rustfs_io_metrics::current_ec_encode_producer_bytes();
+        let writer_baseline = rustfs_io_metrics::current_ec_encode_writer_bytes();
+        let producer_peak_before = rustfs_io_metrics::current_ec_encode_producer_bytes_peak();
+        let writer_peak_before = rustfs_io_metrics::current_ec_encode_writer_bytes_peak();
+        let block_size = match pipeline {
+            EncodePipeline::Batched => usize::try_from(producer_peak_before.max(writer_peak_before).saturating_add(1))
+                .expect("stage peak fits the test address space"),
+            EncodePipeline::Vec | EncodePipeline::BytesMut => 16,
+        };
+        rustfs_io_metrics::set_put_stage_metrics_enabled(true);
+        let erasure = Arc::new(Erasure::new(1, 0, block_size));
+        let batch_blocks = encode_batch_block_count().min(encode_channel_capacity(
+            erasure.shard_size().saturating_mul(erasure.total_shard_count()),
+            erasure_encode_max_inflight_bytes(),
+        ));
+        let blocks_before_pending = match pipeline {
+            EncodePipeline::Batched => batch_blocks,
+            EncodePipeline::Vec | EncodePipeline::BytesMut => 1,
+        };
+        let (reader, reader_blocked, reader_dropped, _final_block) =
+            BlocksThenPendingReader::new(blocks_before_pending, block_size);
+        let writes = Arc::new(std::sync::atomic::AtomicUsize::new(0));
+        let mut writers = vec![Some(bitrot_writer(
+            FailAfterReaderBlocksWriter {
+                reader_blocked,
+                writes: writes.clone(),
+            },
+            block_size,
+        ))];
+
+        let result = match pipeline {
+            EncodePipeline::Vec => erasure.encode_with_ingest_mode(reader, &mut writers, 1, false).await,
+            EncodePipeline::BytesMut => erasure.encode_with_ingest_mode(reader, &mut writers, 1, true).await,
+            EncodePipeline::Batched => erasure.encode_batched(reader, &mut writers, 1).await,
+        };
+
+        let err = match result {
+            Ok(_) => panic!("writer quorum failure should fail the encode pipeline"),
+            Err(err) => err,
+        };
+        assert!(err.to_string().contains("Failed to write data"));
+        tokio::time::timeout(Duration::from_secs(1), reader_dropped)
+            .await
+            .expect("writer failure should abort the blocked producer")
+            .expect("blocked producer should signal reader drop");
+        assert_eq!(
+            writes.load(std::sync::atomic::Ordering::SeqCst),
+            1,
+            "writer failure must stop the pipeline before any additional shard write"
+        );
+        assert_eq!(
+            rustfs_io_metrics::current_ec_encode_inflight_bytes(),
+            gauge_baseline,
+            "writer failure must settle all queued and pending encoded bytes"
+        );
+        assert_eq!(
+            rustfs_io_metrics::current_ec_encode_producer_bytes(),
+            producer_baseline,
+            "writer failure must settle producer stage bytes for every ingest pipeline"
+        );
+        assert_eq!(
+            rustfs_io_metrics::current_ec_encode_writer_bytes(),
+            writer_baseline,
+            "writer failure must settle writer stage bytes for every ingest pipeline"
+        );
+        if matches!(pipeline, EncodePipeline::Batched) {
+            let expected_batch_bytes = u64::try_from(block_size)
+                .expect("block size fits the stage gauge")
+                .checked_mul(u64::try_from(batch_blocks).expect("batch block count fits the stage gauge"))
+                .expect("test batch payload fits the stage gauge");
+            assert!(
+                rustfs_io_metrics::current_ec_encode_producer_bytes_peak() >= producer_peak_before.max(expected_batch_bytes),
+                "batched producer must expose its full pending batch before writer failure"
+            );
+            assert!(
+                rustfs_io_metrics::current_ec_encode_writer_bytes_peak() >= writer_peak_before.max(expected_batch_bytes),
+                "batched writer must expose its full batch before writer failure"
+            );
+        }
+        rustfs_io_metrics::set_put_stage_metrics_enabled(false);
+    }
+
+    async fn aborting_full_queue_settles_pending_send() {
+        const BLOCK_SIZE: usize = 16;
+
+        let gauge_baseline = rustfs_io_metrics::current_ec_encode_inflight_bytes();
+        let producer_baseline = rustfs_io_metrics::current_ec_encode_producer_bytes();
+        let writer_baseline = rustfs_io_metrics::current_ec_encode_writer_bytes();
+        rustfs_io_metrics::set_put_stage_metrics_enabled(true);
+        let erasure = Arc::new(Erasure::new(1, 0, BLOCK_SIZE));
+        let inflight_blocks = encode_channel_capacity(
+            erasure.shard_size().saturating_mul(erasure.total_shard_count()),
+            erasure_encode_max_inflight_bytes(),
+        );
+        let (reader, _reader_blocked, reader_dropped, final_block) =
+            BlocksThenPendingReader::new(inflight_blocks + 2, BLOCK_SIZE);
+        let (writer_entered_tx, writer_entered) = oneshot::channel();
+        let writes = Arc::new(std::sync::atomic::AtomicUsize::new(0));
+        let mut writers = vec![Some(bitrot_writer(
+            StallOnWriteWithSignal {
+                entered: Some(writer_entered_tx),
+                writes: writes.clone(),
+            },
+            BLOCK_SIZE,
+        ))];
+        let erasure_for_task = erasure.clone();
+        let encode = tokio::spawn(async move { erasure_for_task.encode_with_ingest_mode(reader, &mut writers, 1, false).await });
+
+        tokio::time::timeout(Duration::from_secs(1), writer_entered)
+            .await
+            .expect("consumer should start the first writer call")
+            .expect("stalling writer should signal entry");
+        tokio::time::timeout(Duration::from_secs(1), final_block)
+            .await
+            .expect("producer should supply the block whose send fills the queue")
+            .expect("reader should signal final block");
+
+        let expected_queued_bytes =
+            u64::try_from((inflight_blocks + 1) * BLOCK_SIZE).expect("queued byte count should fit the gauge");
+        tokio::time::timeout(Duration::from_secs(1), async {
+            while rustfs_io_metrics::current_ec_encode_inflight_bytes() < gauge_baseline + expected_queued_bytes {
+                tokio::task::yield_now().await;
+            }
+        })
+        .await
+        .expect("producer should account for the pending send after the queue fills");
+        tokio::time::timeout(Duration::from_secs(1), async {
+            while rustfs_io_metrics::current_ec_encode_producer_bytes() == producer_baseline
+                || rustfs_io_metrics::current_ec_encode_writer_bytes() == writer_baseline
+            {
+                tokio::task::yield_now().await;
+            }
+        })
+        .await
+        .expect("full queue must retain producer and writer stage ownership before cancellation");
+
+        encode.abort();
+        assert!(matches!(encode.await, Err(err) if err.is_cancelled()), "encode task should be cancelled");
+        tokio::time::timeout(Duration::from_secs(1), reader_dropped)
+            .await
+            .expect("cancelling a full queue should abort its producer")
+            .expect("full-queue producer should signal reader drop");
+        assert_eq!(
+            writes.load(std::sync::atomic::Ordering::SeqCst),
+            1,
+            "cancellation must not resume the stalled writer"
+        );
+        assert_eq!(
+            rustfs_io_metrics::current_ec_encode_inflight_bytes(),
+            gauge_baseline,
+            "cancelling a full queue must settle queued and pending bytes"
+        );
+        assert_eq!(
+            rustfs_io_metrics::current_ec_encode_producer_bytes(),
+            producer_baseline,
+            "cancelling a full queue must settle the pending producer stage"
+        );
+        assert_eq!(
+            rustfs_io_metrics::current_ec_encode_writer_bytes(),
+            writer_baseline,
+            "cancelling a full queue must settle the stalled writer stage"
+        );
+        rustfs_io_metrics::set_put_stage_metrics_enabled(false);
+    }
+
+    #[tokio::test]
+    #[serial_test::serial]
+    async fn cancelling_vec_encode_drops_blocked_producer() {
+        aborting_encode_drops_blocked_producer(EncodePipeline::Vec).await;
+    }
+
+    #[tokio::test]
+    #[serial_test::serial]
+    async fn cancelling_bytesmut_encode_drops_blocked_producer() {
+        aborting_encode_drops_blocked_producer(EncodePipeline::BytesMut).await;
+    }
+
+    #[tokio::test]
+    #[serial_test::serial]
+    async fn cancelling_batched_encode_drops_blocked_producer() {
+        aborting_encode_drops_blocked_producer(EncodePipeline::Batched).await;
+    }
+
+    #[tokio::test]
+    #[serial_test::serial]
+    async fn vec_writer_error_aborts_blocked_producer() {
+        writer_error_aborts_blocked_producer(EncodePipeline::Vec).await;
+    }
+
+    #[tokio::test]
+    #[serial_test::serial]
+    async fn bytesmut_writer_error_aborts_blocked_producer() {
+        writer_error_aborts_blocked_producer(EncodePipeline::BytesMut).await;
+    }
+
+    #[tokio::test]
+    #[serial_test::serial]
+    async fn batched_writer_error_aborts_blocked_producer() {
+        writer_error_aborts_blocked_producer(EncodePipeline::Batched).await;
+    }
+
+    #[tokio::test]
+    #[serial_test::serial]
+    async fn cancelling_full_queue_settles_pending_send() {
+        aborting_full_queue_settles_pending_send().await;
+    }
+
    #[tokio::test]
    async fn helper_writers_cover_flush_and_shutdown_paths() {
        let mut failing_write = FailingWriteWriter;
@@ -1329,25 +1802,99 @@ mod tests {
    }

    #[tokio::test]
-    async fn drain_queued_inflight_bytes_consumes_pending_blocks() {
-        let (tx, mut rx) = mpsc::channel(2);
-        tx.send(vec![Bytes::from_static(b"queued")]).await.unwrap();
-        drop(tx);
+    #[serial_test::serial]
+    async fn queued_inflight_bytes_are_settled_on_all_queue_exit_paths() {
+        let baseline = rustfs_io_metrics::current_ec_encode_inflight_bytes();
+        let (tx, rx) = mpsc::channel(1);
+        let queued = vec![Bytes::from_static(b"queued")];
+        let queued_bytes = queued_block_bytes(&queued);

-        drain_queued_inflight_bytes(&mut rx).await;
+        send_queued(&tx, queued, queued_bytes)
+            .await
+            .expect("first queue entry should fit");

-        assert!(rx.recv().await.is_none());
+        let blocked = vec![Bytes::from_static(b"blocked")];
+        let blocked_bytes = queued_block_bytes(&blocked);
+        {
+            let pending_send = send_queued(&tx, blocked, blocked_bytes);
+            tokio::pin!(pending_send);
+            assert!(
+                futures::poll!(pending_send.as_mut()).is_pending(),
+                "full queue must suspend producer send"
+            );
+        }
+        assert_eq!(
+            rustfs_io_metrics::current_ec_encode_inflight_bytes(),
+            baseline + u64::try_from(queued_bytes).expect("queue bytes fit the gauge"),
+            "dropping a pending producer send must compensate its bytes"
+        );
+
+        drop(rx);
+        assert_eq!(
+            rustfs_io_metrics::current_ec_encode_inflight_bytes(),
+            baseline,
+            "dropping the receiver must settle every buffered entry"
+        );
+
+        let rejected = vec![Bytes::from_static(b"rejected")];
+        let rejected_bytes = queued_block_bytes(&rejected);
+        assert!(
+            send_queued(&tx, rejected, rejected_bytes).await.is_err(),
+            "closed receiver must reject a new send"
+        );
+        assert_eq!(
+            rustfs_io_metrics::current_ec_encode_inflight_bytes(),
+            baseline,
+            "failed sends must compensate their bytes"
+        );
    }

    #[tokio::test]
-    async fn drain_queued_batched_inflight_bytes_consumes_pending_batches() {
-        let (tx, mut rx) = mpsc::channel(2);
-        tx.send(vec![vec![Bytes::from_static(b"queued")]]).await.unwrap();
-        drop(tx);
+    #[serial_test::serial]
+    async fn queued_batch_entry_settles_bytes_before_handoff() {
+        let baseline = rustfs_io_metrics::current_ec_encode_inflight_bytes();
+        let (tx, rx) = mpsc::channel(2);
+        let mut rx = rx;
+        let batch = vec![vec![Bytes::from_static(b"queued")], vec![Bytes::from_static(b"batch")]];
+        let batch_bytes = queued_batch_bytes(&batch);

-        drain_queued_batched_inflight_bytes(&mut rx).await;
+        send_queued(&tx, batch, batch_bytes).await.expect("batch should be queued");
+        let batch = rx.recv().await.expect("queued batch should be received").into_inner();
+        assert_eq!(batch_bytes, queued_batch_bytes(&batch));

-        assert!(rx.recv().await.is_none());
+        assert_eq!(
+            rustfs_io_metrics::current_ec_encode_inflight_bytes(),
+            baseline,
+            "receiving a batch must settle all contained block bytes before shard writes"
+        );
+    }
+
+    #[tokio::test]
+    #[serial_test::serial]
+    async fn queued_entry_settles_when_a_closed_receiver_accepts_an_outstanding_permit() {
+        let baseline = rustfs_io_metrics::current_ec_encode_inflight_bytes();
+        let (tx, mut rx) = mpsc::channel(1);
+        let permit = tx
+            .clone()
+            .reserve_owned()
+            .await
+            .expect("open receiver should reserve queue capacity");
+        rx.close();
+        assert!(
+            matches!(rx.try_recv(), Err(mpsc::error::TryRecvError::Empty)),
+            "an outstanding permit must leave the closed queue observably empty"
+        );
+
+        let block = vec![Bytes::from_static(b"late-permit")];
+        let block_bytes = queued_block_bytes(&block);
+        permit.send(InflightEntry::new(block, block_bytes));
+        drop(rx);
+
+        assert_eq!(
+            rustfs_io_metrics::current_ec_encode_inflight_bytes(),
+            baseline,
+            "a queue entry sent through an outstanding permit must settle when Tokio drops it"
+        );
    }

    #[tokio::test]
@@ -1394,6 +1941,61 @@ mod tests {
        }
    }

+    #[tokio::test]
+    #[serial_test::serial]
+    async fn bytesmut_streaming_encode_observes_all_payload_stage_peaks() {
+        let queue_baseline = rustfs_io_metrics::current_ec_encode_inflight_bytes();
+        let producer_peak_before = rustfs_io_metrics::current_ec_encode_producer_bytes_peak();
+        let queue_peak_before = rustfs_io_metrics::current_ec_encode_queue_bytes_peak();
+        let writer_peak_before = rustfs_io_metrics::current_ec_encode_writer_bytes_peak();
+        let prior_peak = producer_peak_before.max(queue_peak_before).max(writer_peak_before);
+        let block_size = usize::try_from(prior_peak.saturating_add(1)).expect("stage peak fits the test address space");
+        let erasure = Arc::new(Erasure::new(1, 0, block_size));
+        let encoded_block_bytes = erasure.shard_size() * erasure.total_shard_count();
+        let committed = Arc::new(Mutex::new(Vec::new()));
+        let mut writers = vec![Some(bitrot_writer(DeferredCommitWriter::new(committed.clone()), block_size))];
+        let reader = tokio::io::BufReader::new(Cursor::new(vec![0x5a; block_size * 2]));
+
+        rustfs_io_metrics::set_put_stage_metrics_enabled(true);
+        let result = erasure.encode_with_ingest_mode(reader, &mut writers, 1, true).await;
+        rustfs_io_metrics::set_put_stage_metrics_enabled(false);
+
+        let (_reader, written) = result.expect("bytesmut streaming encode should complete");
+        assert_eq!(written, block_size * 2);
+        assert_eq!(
+            rustfs_io_metrics::current_ec_encode_inflight_bytes(),
+            queue_baseline,
+            "completed streaming encode must not retain queue bytes"
+        );
+        assert_eq!(
+            rustfs_io_metrics::current_ec_encode_producer_bytes(),
+            0,
+            "completed streaming encode must not retain producer bytes"
+        );
+        assert_eq!(
+            rustfs_io_metrics::current_ec_encode_writer_bytes(),
+            0,
+            "completed streaming encode must not retain writer bytes"
+        );
+        let expected_peak = u64::try_from(encoded_block_bytes).expect("encoded block bytes fit the gauge");
+        assert!(
+            rustfs_io_metrics::current_ec_encode_producer_bytes_peak() >= producer_peak_before.max(expected_peak),
+            "producer peak must observe encoded bytes before queue hand-off"
+        );
+        assert!(
+            rustfs_io_metrics::current_ec_encode_queue_bytes_peak() >= queue_peak_before.max(expected_peak),
+            "queue peak must observe encoded bytes pending shard writers"
+        );
+        assert!(
+            rustfs_io_metrics::current_ec_encode_writer_bytes_peak() >= writer_peak_before.max(expected_peak),
+            "writer peak must observe encoded bytes after queue hand-off"
+        );
+        assert!(
+            !committed.lock().expect("committed buffer should be lockable").is_empty(),
+            "stage peak observation must not change writer commit behavior"
+        );
+    }
+
    #[tokio::test]
    async fn encode_streaming_write_quorum_failure_aborts_and_reports_error() {
        const DATA_SHARDS: usize = 2;
@@ -640,7 +640,7 @@ impl Erasure {
    /// # Returns
    /// A vector of encoded shards as `Bytes`.
    #[tracing::instrument(level = "debug", skip_all, fields(data_len=data.len()))]
-    #[cfg_attr(feature = "hotpath", hotpath::measure)]
+    #[hotpath::measure(impl_type = "Erasure")]
    pub fn encode_data(&self, data: &[u8]) -> io::Result<Vec<Bytes>> {
        let shard_size_fn = if self.uses_legacy {
            calc_shard_size_legacy
@@ -688,7 +688,7 @@ impl Erasure {

    /// Encode owned data, avoiding a copy when the caller already has a heap buffer.
    /// Falls back to copying into a new buffer if zero-copy conversion fails.
-    #[cfg_attr(feature = "hotpath", hotpath::measure)]
+    #[hotpath::measure(impl_type = "Erasure")]
    pub fn encode_data_owned(&self, data: Vec<u8>) -> io::Result<Vec<Bytes>> {
        let shard_size_fn = if self.uses_legacy {
            calc_shard_size_legacy
@@ -752,7 +752,7 @@ impl Erasure {
    /// block), the `resize(need_total_size)` below stays within capacity for every
    /// `data_len <= block_size` — both shard-size formulas are monotone in
    /// `data_len` — so this function never reallocates the buffer.
-    #[cfg_attr(feature = "hotpath", hotpath::measure)]
+    #[hotpath::measure(impl_type = "Erasure")]
    pub fn encode_data_bytes_mut(&self, mut data_buffer: BytesMut, data_len: usize) -> io::Result<Vec<Bytes>> {
        let shard_size_fn = if self.uses_legacy {
            calc_shard_size_legacy
@@ -805,7 +805,7 @@ impl Erasure {
    ///
    /// # Returns
    /// Ok if reconstruction succeeds, error otherwise.
-    #[cfg_attr(feature = "hotpath", hotpath::measure)]
+    #[hotpath::measure(impl_type = "Erasure")]
    pub fn decode_data(&self, shards: &mut [Option<Vec<u8>>]) -> io::Result<()> {
        if self.parity_shards > 0 {
            if self.uses_legacy {
@@ -825,7 +825,7 @@ impl Erasure {
    }

    /// Decode and reconstruct missing data shards, then regenerate parity shards.
-    #[cfg_attr(feature = "hotpath", hotpath::measure)]
+    #[hotpath::measure(impl_type = "Erasure")]
    pub fn decode_data_and_parity(&self, shards: &mut [Option<Vec<u8>>]) -> io::Result<()> {
        if self.parity_shards > 0 {
            if self.uses_legacy {
@@ -19,6 +19,8 @@ use crate::diagnostics::get::{
    GET_STAGE_READER_MMAP_PATH_RESOLVE, GET_STAGE_READER_OPEN_MMAP_COPY_FALLBACK, GET_STAGE_READER_OPEN_MMAP_COPY_SUCCESS,
    GET_STAGE_READER_OPEN_STREAM, GET_STAGE_READER_STREAM_FIRST_READ, record_get_stage_duration_if_enabled,
 };
+#[cfg(feature = "hotpath")]
+use crate::disk::FileWriter;
 use crate::disk::{self, DiskAPI as _, DiskStore, FileReader, MmapCopyStageMetrics, error::DiskError};
 use crate::erasure::coding::{BitrotReader, BitrotWriterWrapper, CustomWriter};
 use bytes::Bytes;
@@ -36,6 +38,11 @@ use std::time::Instant;
 use tokio::io::{AsyncRead, ReadBuf};
 use tracing::debug;

+#[cfg(all(test, feature = "hotpath"))]
+tokio::task_local! {
+    static FORCE_MMAP_COPY_FAILURE_FOR_TEST: ();
+}
+
 /// A shard source for the bitrot reader.
 ///
 /// `InMemory` keeps the `Bytes` concrete instead of erasing it behind
@@ -360,10 +367,21 @@ async fn open_disk_reader(
            mmap_copy_stage: GET_STAGE_READER_MMAP_COPY_BUFFER,
            direct_read_copy_stage: GET_STAGE_READER_MMAP_DIRECT_READ_COPY,
        });
-        match disk
-            .read_file_mmap_copy_with_metrics(bucket, path, offset, length, mmap_metrics)
-            .await
-        {
+        let mmap_result = {
+            #[cfg(all(test, feature = "hotpath"))]
+            if FORCE_MMAP_COPY_FAILURE_FOR_TEST.try_with(|_| ()).is_ok() {
+                Err(DiskError::other("forced mmap-copy failure for test"))
+            } else {
+                disk.read_file_mmap_copy_with_metrics(bucket, path, offset, length, mmap_metrics)
+                    .await
+            }
+            #[cfg(not(all(test, feature = "hotpath")))]
+            {
+                disk.read_file_mmap_copy_with_metrics(bucket, path, offset, length, mmap_metrics)
+                    .await
+            }
+        };
+        match mmap_result {
            Ok(bytes) => {
                let duration_ms = zero_copy_start.elapsed().as_secs_f64() * 1000.0;

@@ -398,7 +416,11 @@ async fn open_disk_reader(
                }

                return match stream_result {
-                    Ok(reader) => Ok(wrap_first_read_metrics(reader, metrics_path)),
+                    Ok(reader) => {
+                        #[cfg(feature = "hotpath")]
+                        let reader = instrument_raw_shard_reader(reader, disk.is_local());
+                        Ok(wrap_first_read_metrics(reader, metrics_path))
+                    }
                    Err(_) => Err(err),
                };
            }
@@ -407,6 +429,8 @@ async fn open_disk_reader(

    let stream_start = stage_metrics_enabled.then(Instant::now);
    let reader = disk.read_file_stream(bucket, path, offset, length).await?;
+    #[cfg(feature = "hotpath")]
+    let reader = instrument_raw_shard_reader(reader, disk.is_local());
    if let Some(metrics_path) = metrics_path {
        record_get_stage_duration_if_enabled(metrics_path, GET_STAGE_READER_OPEN_STREAM, stream_start);
    }
@@ -427,6 +451,37 @@ fn wrap_first_read_metrics(reader: FileReader, metrics_path: Option<&'static str
    ShardReader::Stream(reader)
 }

+// The labels are deliberately fixed: object keys, disk paths, and remote hosts
+// are all high-cardinality or sensitive and belong nowhere in a profiling report.
+#[cfg(feature = "hotpath")]
+const RAW_SHARD_READ_LOCAL_LABEL: &str = "EC raw shard read local";
+#[cfg(feature = "hotpath")]
+const RAW_SHARD_READ_REMOTE_LABEL: &str = "EC raw shard read remote";
+#[cfg(feature = "hotpath")]
+const RAW_SHARD_WRITE_LOCAL_LABEL: &str = "EC raw shard write local";
+#[cfg(feature = "hotpath")]
+const RAW_SHARD_WRITE_REMOTE_LABEL: &str = "EC raw shard write remote";
+
+#[cfg(feature = "hotpath")]
+fn instrument_raw_shard_reader(reader: FileReader, is_local: bool) -> FileReader {
+    // `io!` aggregates by call site, so the local and remote branches must remain distinct.
+    if is_local {
+        Box::new(hotpath::io!(reader, label = RAW_SHARD_READ_LOCAL_LABEL))
+    } else {
+        Box::new(hotpath::io!(reader, label = RAW_SHARD_READ_REMOTE_LABEL))
+    }
+}
+
+#[cfg(feature = "hotpath")]
+fn instrument_raw_shard_writer(writer: FileWriter, is_local: bool) -> FileWriter {
+    // `io!` aggregates by call site, so the local and remote branches must remain distinct.
+    if is_local {
+        Box::new(hotpath::io!(writer, label = RAW_SHARD_WRITE_LOCAL_LABEL))
+    } else {
+        Box::new(hotpath::io!(writer, label = RAW_SHARD_WRITE_REMOTE_LABEL))
+    }
+}
+
 fn bitrot_encoded_range(offset: usize, length: usize, shard_size: usize, checksum_algo: HashAlgorithm) -> (usize, usize) {
    (
        offset.div_ceil(shard_size) * checksum_algo.size() + offset,
@@ -686,6 +741,8 @@ pub async fn create_bitrot_writer(
        };

        let file = disk.create_file("", volume, path, length).await?;
+        #[cfg(feature = "hotpath")]
+        let file = instrument_raw_shard_writer(file, disk.is_local());
        CustomWriter::new_tokio_writer(file)
    } else {
        return Err(DiskError::DiskNotFound);
@@ -698,6 +755,194 @@ pub async fn create_bitrot_writer(
 mod tests {
    use super::*;

+    #[cfg(feature = "hotpath")]
+    use crate::cluster::rpc::RemoteDisk;
+    #[cfg(feature = "hotpath")]
+    use crate::cluster::rpc::internode_data_transport::{
+        InternodeDataTransport, InternodeDataTransportCapabilities, ReadStreamRequest, WalkDirStreamRequest, WriteStreamRequest,
+    };
+    #[cfg(feature = "hotpath")]
+    use crate::disk::{Disk, DiskOption, error::Result};
+
+    #[cfg(feature = "hotpath")]
+    #[derive(Debug, Clone, Default)]
+    struct TestRemoteDataTransport {
+        bytes: Arc<Mutex<Vec<u8>>>,
+        write_error: Option<io::ErrorKind>,
+    }
+
+    #[cfg(feature = "hotpath")]
+    impl TestRemoteDataTransport {
+        fn with_write_error(kind: io::ErrorKind) -> Self {
+            Self {
+                bytes: Arc::default(),
+                write_error: Some(kind),
+            }
+        }
+
+        fn bytes(&self) -> Vec<u8> {
+            self.bytes
+                .lock()
+                .expect("test remote transport bytes lock should not be poisoned")
+                .clone()
+        }
+    }
+
+    #[cfg(feature = "hotpath")]
+    #[derive(Debug)]
+    struct TestRemoteWriter {
+        bytes: Arc<Mutex<Vec<u8>>>,
+        write_error: Option<io::ErrorKind>,
+    }
+
+    #[cfg(feature = "hotpath")]
+    impl tokio::io::AsyncWrite for TestRemoteWriter {
+        fn poll_write(self: Pin<&mut Self>, _cx: &mut Context<'_>, buf: &[u8]) -> Poll<io::Result<usize>> {
+            if let Some(kind) = self.write_error {
+                return Poll::Ready(Err(io::Error::from(kind)));
+            }
+            self.bytes
+                .lock()
+                .expect("test remote transport bytes lock should not be poisoned")
+                .extend_from_slice(buf);
+            Poll::Ready(Ok(buf.len()))
+        }
+
+        fn poll_flush(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+            Poll::Ready(Ok(()))
+        }
+
+        fn poll_shutdown(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+            Poll::Ready(Ok(()))
+        }
+    }
+
+    #[cfg(feature = "hotpath")]
+    #[async_trait::async_trait]
+    impl InternodeDataTransport for TestRemoteDataTransport {
+        async fn open_read(&self, _request: ReadStreamRequest) -> Result<FileReader> {
+            Ok(Box::new(Cursor::new(self.bytes())))
+        }
+
+        async fn open_write(&self, _request: WriteStreamRequest) -> Result<FileWriter> {
+            Ok(Box::new(TestRemoteWriter {
+                bytes: Arc::clone(&self.bytes),
+                write_error: self.write_error,
+            }))
+        }
+
+        async fn open_walk_dir(&self, _request: WalkDirStreamRequest) -> Result<FileReader> {
+            panic!("open_walk_dir must not be used by the raw shard I/O test")
+        }
+
+        fn name(&self) -> &'static str {
+            "bitrot-test-remote"
+        }
+
+        fn capabilities(&self) -> InternodeDataTransportCapabilities {
+            InternodeDataTransportCapabilities::tcp_http()
+        }
+    }
+
+    async fn local_test_disk() -> (DiskStore, tempfile::TempDir) {
+        use crate::disk::endpoint::Endpoint;
+        use crate::disk::{DiskOption, new_disk};
+
+        let dir = tempfile::tempdir().expect("tempdir should be created");
+        let mut endpoint =
+            Endpoint::try_from(dir.path().to_str().expect("tempdir path should be utf8")).expect("endpoint should parse");
+        endpoint.set_pool_index(0);
+        endpoint.set_set_index(0);
+        endpoint.set_disk_index(0);
+        let disk = new_disk(
+            &endpoint,
+            &DiskOption {
+                cleanup: false,
+                health_check: false,
+            },
+        )
+        .await
+        .expect("local disk should be created");
+
+        (disk, dir)
+    }
+
+    #[cfg(feature = "hotpath")]
+    async fn remote_test_disk(transport: TestRemoteDataTransport) -> (DiskStore, TestRemoteDataTransport) {
+        use crate::disk::endpoint::Endpoint;
+
+        let endpoint = Endpoint {
+            url: url::Url::parse("http://remote-node:9000/data/rustfs0").expect("test remote endpoint should parse"),
+            is_local: false,
+            pool_idx: 0,
+            set_idx: 0,
+            disk_idx: 0,
+        };
+        let remote = RemoteDisk::new(
+            &endpoint,
+            &DiskOption {
+                cleanup: false,
+                health_check: false,
+            },
+            Arc::new(transport.clone()),
+        )
+        .await
+        .expect("test remote disk should be created");
+
+        (Arc::new(Disk::Remote(Box::new(remote))), transport)
+    }
+
+    async fn round_trip_disk_bitrot(disk: &DiskStore, bucket: &str, path: &str, payload: &[u8], shard_size: usize) -> Vec<u8> {
+        disk.make_volume(bucket).await.expect("volume should be created");
+        let mut writer = create_bitrot_writer(
+            false,
+            Some(disk),
+            bucket,
+            path,
+            i64::try_from(payload.len()).expect("test payload length should fit i64"),
+            shard_size,
+            HashAlgorithm::None,
+        )
+        .await
+        .expect("disk bitrot writer should open the raw shard file");
+        for chunk in payload.chunks(shard_size) {
+            writer
+                .write(chunk)
+                .await
+                .expect("disk bitrot writer should preserve each shard block");
+        }
+        writer.shutdown().await.expect("disk bitrot writer should close cleanly");
+
+        let mut reader = create_bitrot_reader(
+            None,
+            Some(disk),
+            bucket,
+            path,
+            0,
+            payload.len(),
+            shard_size,
+            HashAlgorithm::None,
+            false,
+            false,
+        )
+        .await
+        .expect("disk bitrot reader should open the raw shard file")
+        .expect("disk bitrot reader should exist");
+        let mut actual = Vec::with_capacity(payload.len());
+        while actual.len() < payload.len() {
+            let remaining = payload.len() - actual.len();
+            let mut chunk = vec![0; remaining.min(shard_size)];
+            let read = reader
+                .read(&mut chunk)
+                .await
+                .expect("disk bitrot reader should return the complete shard body");
+            assert!(read > 0, "disk bitrot reader must not end before the expected shard body is complete");
+            actual.extend_from_slice(&chunk[..read]);
+        }
+
+        actual
+    }
+
    #[test]
    fn object_mmap_read_enabled_accepts_legacy_zero_copy_alias() {
        temp_env::with_vars(
@@ -724,6 +969,214 @@ mod tests {
        );
    }

+    #[cfg(feature = "hotpath")]
+    #[test]
+    fn raw_shard_io_wrappers_report_fixed_labels_and_preserve_bytes() {
+        const CHILD_ENV: &str = "RUSTFS_HOTPATH_RAW_SHARD_IO_TEST_CHILD";
+        if std::env::var_os(CHILD_ENV).is_none() {
+            let status = std::process::Command::new(std::env::current_exe().expect("test executable path should be available"))
+                .arg("--exact")
+                .arg("io_support::bitrot::tests::raw_shard_io_wrappers_report_fixed_labels_and_preserve_bytes")
+                .arg("--nocapture")
+                .env(CHILD_ENV, "1")
+                .status()
+                .expect("isolated HotPath I/O test process should start");
+            assert!(status.success(), "isolated HotPath I/O test process should pass");
+            return;
+        }
+
+        tokio::runtime::Builder::new_current_thread()
+            .enable_all()
+            .build()
+            .expect("test runtime should be created")
+            .block_on(raw_shard_io_wrappers_report_fixed_labels_and_preserve_bytes_in_isolated_process());
+    }
+
+    #[cfg(feature = "hotpath")]
+    async fn raw_shard_io_wrappers_report_fixed_labels_and_preserve_bytes_in_isolated_process() {
+        use hotpath::{Format, HotpathGuardBuilder, Section};
+        use tokio::io::AsyncReadExt;
+
+        let report_dir = tempfile::tempdir().expect("report tempdir should be created");
+        let report_path = report_dir.path().join("hotpath-io.json");
+        let guard = HotpathGuardBuilder::new("raw_shard_io_test")
+            .format(Format::Json)
+            .output_path(&report_path)
+            .sections(vec![Section::Io])
+            .build();
+
+        let (disk, _dir) = local_test_disk().await;
+        let bucket = "test-bucket";
+        let path = "obj/hotpath-part.1";
+        let payload = b"local shard bytes";
+        let shard_size = 4;
+        let local_read = round_trip_disk_bitrot(&disk, bucket, path, payload, shard_size).await;
+        assert_eq!(local_read, payload, "local raw shard I/O instrumentation must not alter stored bytes");
+
+        let fallback_path = "obj/hotpath-mmap-fallback-part.1";
+        let fallback_payload = b"mmap fallback shard bytes";
+        disk.write_all("test-bucket", fallback_path, Bytes::from_static(fallback_payload))
+            .await
+            .expect("fallback shard file should be written");
+        let mut fallback_reader = FORCE_MMAP_COPY_FAILURE_FOR_TEST
+            .scope((), open_disk_reader(&disk, bucket, fallback_path, 0, fallback_payload.len(), true, None))
+            .await
+            .expect("mmap-copy failure should fall back to a raw shard stream");
+        assert!(
+            matches!(fallback_reader, ShardReader::Stream(_)),
+            "forced mmap-copy failure must use the streaming fallback"
+        );
+        let mut fallback_read = Vec::new();
+        fallback_reader
+            .read_to_end(&mut fallback_read)
+            .await
+            .expect("mmap-copy fallback stream should preserve bytes");
+        assert_eq!(fallback_read, fallback_payload);
+
+        let (remote_disk, remote_transport) = remote_test_disk(TestRemoteDataTransport::default()).await;
+        let remote_payload = b"remote shard bytes";
+        let mut remote_writer = create_bitrot_writer(
+            false,
+            Some(&remote_disk),
+            bucket,
+            "obj/hotpath-remote-part.1",
+            i64::try_from(remote_payload.len()).expect("remote payload length should fit i64"),
+            shard_size,
+            HashAlgorithm::None,
+        )
+        .await
+        .expect("remote bitrot writer should use the production raw writer path");
+        for chunk in remote_payload.chunks(shard_size) {
+            remote_writer
+                .write(chunk)
+                .await
+                .expect("remote bitrot writer should preserve bytes");
+        }
+        remote_writer
+            .shutdown()
+            .await
+            .expect("remote bitrot writer should close cleanly");
+        assert_eq!(remote_transport.bytes(), remote_payload);
+
+        let mut reader = create_bitrot_reader(
+            None,
+            Some(&remote_disk),
+            bucket,
+            "obj/hotpath-remote-part.1",
+            0,
+            remote_payload.len(),
+            shard_size,
+            HashAlgorithm::None,
+            false,
+            true,
+        )
+        .await
+        .expect("remote bitrot reader should use the production raw reader path")
+        .expect("remote bitrot reader should exist");
+        let mut remote_read = Vec::with_capacity(remote_payload.len());
+        while remote_read.len() < remote_payload.len() {
+            let remaining = remote_payload.len() - remote_read.len();
+            let mut chunk = vec![0; remaining.min(shard_size)];
+            let read = reader
+                .read(&mut chunk)
+                .await
+                .expect("remote bitrot reader should preserve bytes");
+            assert!(read > 0, "remote bitrot reader must not end before the expected shard body is complete");
+            remote_read.extend_from_slice(&chunk[..read]);
+        }
+        assert_eq!(remote_read, remote_payload);
+
+        let (failing_remote_disk, _) = remote_test_disk(TestRemoteDataTransport::with_write_error(io::ErrorKind::Other)).await;
+        let mut failing_writer = create_bitrot_writer(
+            false,
+            Some(&failing_remote_disk),
+            bucket,
+            "obj/hotpath-remote-write-error-part.1",
+            4,
+            shard_size,
+            HashAlgorithm::None,
+        )
+        .await
+        .expect("failing remote bitrot writer should open before its first write");
+        let write_error = failing_writer
+            .write(b"fail")
+            .await
+            .expect_err("raw shard writer failures must remain visible through the bitrot writer");
+        assert_eq!(write_error.kind(), io::ErrorKind::Other);
+
+        let (would_block_remote_disk, _) =
+            remote_test_disk(TestRemoteDataTransport::with_write_error(io::ErrorKind::WouldBlock)).await;
+        let mut would_block_writer = create_bitrot_writer(
+            false,
+            Some(&would_block_remote_disk),
+            bucket,
+            "obj/hotpath-remote-write-would-block-part.1",
+            4,
+            shard_size,
+            HashAlgorithm::None,
+        )
+        .await
+        .expect("would-block remote bitrot writer should open before its first write");
+        let would_block = would_block_writer
+            .write(b"wait")
+            .await
+            .expect_err("would-block must remain visible to the caller");
+        assert_eq!(would_block.kind(), io::ErrorKind::WouldBlock);
+
+        drop(guard);
+        let report = std::fs::read_to_string(&report_path).expect("HotPath I/O report should be written");
+        let report: serde_json::Value = serde_json::from_str(&report).expect("HotPath I/O report should be valid JSON");
+        let entries = report["io"]["data"]
+            .as_array()
+            .expect("HotPath I/O report should include data rows");
+        let io_bytes = |label: &str, direction: &str| {
+            let byte_count: u64 = entries
+                .iter()
+                .filter(|entry| entry["label"].as_str().is_some_and(|entry_label| entry_label == label))
+                .filter_map(|entry| entry[direction]["bytes"].as_u64())
+                .sum();
+            assert!(byte_count > 0, "report must include fixed label {label}");
+            byte_count
+        };
+        let io_errors = |label: &str, direction: &str| {
+            entries
+                .iter()
+                .filter(|entry| entry["label"].as_str().is_some_and(|entry_label| entry_label == label))
+                .filter_map(|entry| entry[direction]["errors"].as_u64())
+                .sum::<u64>()
+        };
+        let payload_len = u64::try_from(payload.len()).expect("test payload length should fit u64");
+        assert_eq!(
+            io_bytes(RAW_SHARD_READ_LOCAL_LABEL, "read"),
+            payload_len + u64::try_from(fallback_payload.len()).expect("fallback payload length should fit u64")
+        );
+        assert_eq!(io_bytes(RAW_SHARD_WRITE_LOCAL_LABEL, "write"), payload_len);
+        assert_eq!(
+            io_bytes(RAW_SHARD_READ_REMOTE_LABEL, "read"),
+            u64::try_from(remote_payload.len()).expect("remote payload length should fit u64")
+        );
+        assert_eq!(
+            io_bytes(RAW_SHARD_WRITE_REMOTE_LABEL, "write"),
+            u64::try_from(remote_payload.len()).expect("remote payload length should fit u64")
+        );
+        assert_eq!(
+            io_errors(RAW_SHARD_WRITE_REMOTE_LABEL, "write"),
+            1,
+            "the wrapper must record the real remote writer failure without changing it, while excluding WouldBlock"
+        );
+        for label in [
+            RAW_SHARD_READ_LOCAL_LABEL,
+            RAW_SHARD_READ_REMOTE_LABEL,
+            RAW_SHARD_WRITE_LOCAL_LABEL,
+            RAW_SHARD_WRITE_REMOTE_LABEL,
+        ] {
+            assert!(
+                !label.contains(['/', ':', '?', '@']),
+                "raw shard I/O labels must not carry a path, host, query, or credential delimiter: {label}"
+            );
+        }
+    }
+
    #[test]
    fn object_mmap_read_max_length_defaults_and_env_override() {
        temp_env::with_var(ENV_OBJECT_MMAP_READ_MAX_LENGTH, None::<&str>, || {
@@ -741,25 +1194,9 @@ mod tests {
    // be materialized in memory by the mmap-copy path; over-cap reads stream.
    #[tokio::test]
    async fn open_disk_reader_streams_when_length_exceeds_mmap_cap() {
-        use crate::disk::endpoint::Endpoint;
-        use crate::disk::{DiskOption, new_disk};
        use tokio::io::AsyncReadExt;

-        let dir = tempfile::tempdir().expect("tempdir should be created");
-        let mut endpoint =
-            Endpoint::try_from(dir.path().to_str().expect("tempdir path should be utf8")).expect("endpoint should parse");
-        endpoint.set_pool_index(0);
-        endpoint.set_set_index(0);
-        endpoint.set_disk_index(0);
-        let disk = new_disk(
-            &endpoint,
-            &DiskOption {
-                cleanup: false,
-                health_check: false,
-            },
-        )
-        .await
-        .expect("local disk should be created");
+        let (disk, _dir) = local_test_disk().await;

        let payload = vec![7u8; 4096];
        disk.make_volume("test-bucket").await.expect("volume should be created");
@@ -814,6 +1251,17 @@ mod tests {
        .await;
    }

+    #[tokio::test]
+    async fn disk_bitrot_reader_and_writer_preserve_full_shard_body() {
+        let (disk, _dir) = local_test_disk().await;
+        let bucket = "test-bucket";
+        let path = "obj/wrapped-part.1";
+        let payload = b"wrapped shard body";
+        let actual = round_trip_disk_bitrot(&disk, bucket, path, payload, 4).await;
+
+        assert_eq!(actual, payload, "raw shard I/O instrumentation must not alter stored bytes");
+    }
+
    #[tokio::test]
    async fn test_create_bitrot_reader_with_inline_data() {
        let test_data = b"hello world test data";
@@ -203,7 +203,7 @@ fn get_all_sets<T: AsRef<str>>(set_drive_count: usize, is_ellipses: bool, args:
    for args in set_args.iter() {
        for arg in args {
            if unique_args.contains(arg) {
-                return Err(Error::other(format!("Input args {arg} has duplicate ellipses")));
+                return Err(Error::other("input arguments contain a duplicate endpoint after ellipsis expansion"));
            }
            unique_args.insert(arg);
        }
@@ -924,4 +924,15 @@ mod test {
            }
        }
    }
+
+    #[test]
+    fn layout_errors_do_not_echo_url_credentials() {
+        for volumes in [
+            vec!["http://:duplicate-secret@server/path", "http://:duplicate-secret@server/path"],
+            vec!["http://:ellipsis...secret@server/path"],
+        ] {
+            let err = DisksLayout::from_volumes(&volumes).unwrap_err();
+            assert!(!err.to_string().contains("secret"), "layout error leaked endpoint credentials: {err}");
+        }
+    }
 }
@@ -88,6 +88,7 @@ impl TryFrom<&str> for Endpoint {
                // - All field should be empty except Host and Path.
                if !((url.scheme() == "http" || url.scheme() == "https")
                    && url.username().is_empty()
+                    && url.password().is_none()
                    && url.fragment().is_none()
                    && url.query().is_none())
                {
@@ -366,6 +367,12 @@ mod test {
                expected_type: None,
                expected_err: Some(Error::other("invalid URL endpoint format")),
            },
+            TestCase {
+                arg: "http://:topsecret@server/path",
+                expected_endpoint: None,
+                expected_type: None,
+                expected_err: Some(Error::other("invalid URL endpoint format")),
+            },
            TestCase {
                arg: "http://:/path",
                expected_endpoint: None,
@@ -505,8 +512,18 @@ mod test {
        let endpoint = Endpoint::try_from("http://example.com:9000/path").unwrap();
        assert_eq!(endpoint.host_port(), "example.com:9000");

-        let endpoint_no_port = Endpoint::try_from("https://example.com/path").unwrap();
-        assert_eq!(endpoint_no_port.host_port(), "example.com");
+        for endpoint in [
+            Endpoint::try_from("http://example.com/path").unwrap(),
+            Endpoint::try_from("http://example.com:80/path").unwrap(),
+        ] {
+            assert_eq!(endpoint.host_port(), "example.com");
+        }
+        for endpoint in [
+            Endpoint::try_from("https://example.com/path").unwrap(),
+            Endpoint::try_from("https://example.com:443/path").unwrap(),
+        ] {
+            assert_eq!(endpoint.host_port(), "example.com");
+        }

        let file_endpoint = Endpoint::try_from("/tmp/data").unwrap();
        assert_eq!(file_endpoint.host_port(), "");
@@ -18,7 +18,7 @@ use serde::{Deserialize, Serialize};
 use serde_json::Error as JsonError;
 use uuid::Uuid;

-#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq, Hash)]
 pub enum FormatMetaVersion {
    #[serde(rename = "1")]
    V1,
@@ -27,7 +27,7 @@ pub enum FormatMetaVersion {
    Unknown,
 }

-#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq, Hash)]
 pub enum FormatBackend {
    #[serde(rename = "xl")]
    Erasure,
@@ -64,7 +64,7 @@ pub struct FormatErasureV3 {
    pub distribution_algo: DistributionAlgoVersion,
 }

-#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq, Hash)]
 pub enum FormatErasureVersion {
    #[serde(rename = "1")]
    V1,
@@ -77,7 +77,7 @@ pub enum FormatErasureVersion {
    Unknown,
 }

-#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq, Hash)]
 pub enum DistributionAlgoVersion {
    #[serde(rename = "CRCMOD")]
    V1,
@@ -121,6 +121,15 @@ pub struct FormatV3 {
    pub disk_info: Option<DiskInfo>,
 }

+pub(crate) type SharedFormatIdentity<'a> = (
+    &'a FormatMetaVersion,
+    &'a FormatBackend,
+    &'a Uuid,
+    &'a FormatErasureVersion,
+    &'a [Vec<Uuid>],
+    &'a DistributionAlgoVersion,
+);
+
 impl TryFrom<&[u8]> for FormatV3 {
    type Error = JsonError;

@@ -198,52 +207,24 @@ impl FormatV3 {
    }

    pub fn check_other(&self, other: &FormatV3) -> Result<()> {
-        let mut tmp = other.clone();
-        let this = tmp.erasure.this;
-        tmp.erasure.this = Uuid::nil();
-
-        if self.erasure.sets.len() != other.erasure.sets.len() {
-            return Err(Error::other(format!(
-                "Expected number of sets {}, got {}",
-                self.erasure.sets.len(),
-                other.erasure.sets.len()
-            )));
+        if self.shared_identity() != other.shared_identity() {
+            return Err(Error::other("storage formats do not match"));
        }

-        for i in 0..self.erasure.sets.len() {
-            if self.erasure.sets[i].len() != other.erasure.sets[i].len() {
-                return Err(Error::other(format!(
-                    "Each set should be of same size, expected {}, got {}",
-                    self.erasure.sets[i].len(),
-                    other.erasure.sets[i].len()
-                )));
-            }
+        self.find_disk_index_by_disk_id(other.erasure.this).map(|_| ())
+    }

-            for j in 0..self.erasure.sets[i].len() {
-                if self.erasure.sets[i][j] != other.erasure.sets[i][j] {
-                    return Err(Error::other(format!(
-                        "UUID on positions {}:{} do not match with, expected {:?} got {:?}: (%w)",
-                        i,
-                        j,
-                        self.erasure.sets[i][j].to_string(),
-                        other.erasure.sets[i][j].to_string(),
-                    )));
-                }
-            }
-        }
-
-        for i in 0..tmp.erasure.sets.len() {
-            for j in 0..tmp.erasure.sets[i].len() {
-                if this == tmp.erasure.sets[i][j] {
-                    return Ok(());
-                }
-            }
-        }
-
-        Err(Error::other(format!(
-            "DriveID {:?} not found in any drive sets {:?}",
-            this, other.erasure.sets
-        )))
+    /// Fields that must agree across every disk in one erasure format,
+    /// excluding the disk-specific `this` UUID and runtime-only `disk_info`.
+    pub(crate) fn shared_identity(&self) -> SharedFormatIdentity<'_> {
+        (
+            &self.version,
+            &self.format,
+            &self.id,
+            &self.erasure.version,
+            &self.erasure.sets,
+            &self.erasure.distribution_algo,
+        )
    }
 }

@@ -437,6 +418,30 @@ mod test {
        assert!(result.is_ok());
    }

+    #[test]
+    fn test_check_other_rejects_shared_identity_mismatches() {
+        type FormatMutation = (&'static str, fn(&mut FormatV3));
+
+        let format = FormatV3::new(1, 2);
+        let mutations: [FormatMutation; 5] = [
+            ("meta version", |other| other.version = FormatMetaVersion::Unknown),
+            ("backend", |other| other.format = FormatBackend::ErasureSingle),
+            ("deployment id", |other| other.id = Uuid::new_v4()),
+            ("erasure version", |other| other.erasure.version = FormatErasureVersion::V2),
+            ("distribution algorithm", |other| {
+                other.erasure.distribution_algo = DistributionAlgoVersion::V2
+            }),
+        ];
+
+        for (field, mutate) in mutations {
+            let mut other = format.clone();
+            other.erasure.this = format.erasure.sets[0][0];
+            mutate(&mut other);
+
+            assert!(format.check_other(&other).is_err(), "{field} mismatch must be rejected");
+        }
+    }
+
    #[test]
    fn test_check_other_different_set_count() {
        let format1 = FormatV3::new(2, 4);
@@ -12,8 +12,10 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.

+#![recursion_limit = "256"]
+
 /// Scope-based hotpath measurement for `#[async_trait]` methods, where
-/// `#[cfg_attr(feature = "hotpath", hotpath::measure)]` would only time the boxed-future construction.
+/// `#[hotpath::measure]` would only time the boxed-future construction.
 /// The guard records wall time from this statement until the enclosing
 /// (desugared) async block completes, including early returns via `?`.
 #[cfg(feature = "hotpath")]
@@ -0,0 +1,80 @@
+// Copyright 2024 RustFS Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use async_trait::async_trait;
+use http::{HeaderMap, HeaderValue};
+use std::collections::HashMap;
+use std::error::Error;
+use std::fmt::{Display, Formatter};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum ReadEncryptionMode {
+    Direct { base_nonce: [u8; 12] },
+    Object,
+}
+
+pub struct ReadEncryptionMaterial {
+    pub key_bytes: [u8; 32],
+    pub mode: ReadEncryptionMode,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum EncryptionResolutionErrorKind {
+    InvalidRequest,
+    InvalidMetadata,
+    ServiceUnavailable,
+    DecryptionFailed,
+}
+
+#[derive(Debug)]
+pub struct EncryptionResolutionError {
+    kind: EncryptionResolutionErrorKind,
+    message: String,
+}
+
+impl EncryptionResolutionError {
+    pub fn new(kind: EncryptionResolutionErrorKind, message: impl Into<String>) -> Self {
+        Self {
+            kind,
+            message: message.into(),
+        }
+    }
+
+    pub fn kind(&self) -> EncryptionResolutionErrorKind {
+        self.kind
+    }
+}
+
+impl Display for EncryptionResolutionError {
+    fn fmt(&self, formatter: &mut Formatter<'_>) -> std::fmt::Result {
+        formatter.write_str(&self.message)
+    }
+}
+
+impl Error for EncryptionResolutionError {}
+
+pub struct ReadEncryptionRequest<'a> {
+    pub bucket: &'a str,
+    pub object: &'a str,
+    pub metadata: &'a HashMap<String, String>,
+    pub headers: &'a HeaderMap<HeaderValue>,
+}
+
+#[async_trait]
+pub trait ObjectEncryptionResolver: Send + Sync {
+    async fn resolve_read_material(
+        &self,
+        request: ReadEncryptionRequest<'_>,
+    ) -> Result<Option<ReadEncryptionMaterial>, EncryptionResolutionError>;
+}
@@ -84,6 +84,7 @@ pub(crate) fn legacy_encrypted_range_seek_enabled() -> bool {
 }

 mod body_cache_hook;
+mod encryption;
 mod hook_slot;
 mod object_mutation_hook;
 mod readers;
@@ -98,6 +99,10 @@ pub use body_cache_hook::{
 pub(crate) use body_cache_hook::{
    get_object_body_cache_hook, get_object_body_cache_hook_suppressed, without_get_object_body_cache_hook,
 };
+pub use encryption::{
+    EncryptionResolutionError, EncryptionResolutionErrorKind, ObjectEncryptionResolver, ReadEncryptionMaterial,
+    ReadEncryptionMode, ReadEncryptionRequest,
+};
 pub(crate) use object_mutation_hook::notify_object_mutation;
 pub use object_mutation_hook::{ObjectMutationHook, register_object_mutation_hook, unregister_object_mutation_hook};
 pub use readers::*;
@@ -273,29 +273,9 @@ impl ObjectInfo {
    }

    pub fn is_encrypted(&self) -> bool {
-        // Corresponding to the logic in rustfs/src/sse.rs/encryption_material_to_metadata function
-        use rustfs_utils::http::{SSEC_ALGORITHM_HEADER, SSEC_KEY_HEADER, SSEC_KEY_MD5_HEADER};
-
-        self.user_defined.keys().any(|key| {
-            let lower = key.to_ascii_lowercase();
-            lower.starts_with("x-minio-encryption-")
-                || lower.starts_with("x-minio-internal-server-side-encryption-")
-                || matches!(
-                    lower.as_str(),
-                    "x-minio-internal-encrypted-multipart"
-                        | "x-rustfs-encryption-key"
-                        | "x-rustfs-encryption-algorithm"
-                        | "x-rustfs-encryption-iv"
-                        | "x-rustfs-encryption-key-id"
-                        | "x-rustfs-encryption-context"
-                        | "x-rustfs-encryption-tag"
-                        | "x-amz-server-side-encryption-aws-kms-key-id"
-                        | SSEC_ALGORITHM_HEADER
-                        | SSEC_KEY_HEADER
-                        | SSEC_KEY_MD5_HEADER
-                        | "x-amz-server-side-encryption"
-                )
-        })
+        self.user_defined
+            .keys()
+            .any(|key| rustfs_utils::http::is_object_encryption_marker(key))
    }

    /// Maximum inline size for non-versioned objects (128 KiB).
@@ -339,26 +319,7 @@ impl ObjectInfo {
    }

    pub fn encryption_original_size(&self) -> std::io::Result<Option<i64>> {
-        let actual_size = rustfs_utils::http::get_str(&self.user_defined, rustfs_utils::http::SUFFIX_ACTUAL_SIZE);
-        if let Some(size_str) = self
-            .user_defined
-            .get("x-rustfs-encryption-original-size")
-            .map(String::as_str)
-            .or_else(|| {
-                self.user_defined
-                    .get("x-amz-server-side-encryption-customer-original-size")
-                    .map(String::as_str)
-            })
-            .or(actual_size.as_deref())
-            && !size_str.is_empty()
-        {
-            let size = size_str
-                .parse::<i64>()
-                .map_err(|e| std::io::Error::other(format!("Failed to parse encryption original size: {e}")))?;
-            return Ok(Some(size));
-        }
-
-        Ok(None)
+        rustfs_utils::http::get_object_encryption_original_size(&self.user_defined)
    }

    pub fn decrypted_size(&self) -> std::io::Result<i64> {
@@ -388,9 +349,6 @@ impl ObjectInfo {
            return Ok(actual_size);
        }

-        // Check if object is encrypted
-        // Managed SSE stores original size in x-rustfs-encryption-original-size metadata
-        // SSE-C stores original size in x-amz-server-side-encryption-customer-original-size
        if let Some(size) = self.encryption_original_size()? {
            return Ok(size);
        }
@@ -881,6 +839,19 @@ mod tests {
        assert!(!object.is_inline_fast_path_eligible(), "transitioned objects must fall back");
    }

+    #[test]
+    fn minio_internal_encryption_metadata_is_not_treated_as_plaintext() {
+        let object = ObjectInfo {
+            user_defined: Arc::new(HashMap::from([(
+                "X-Minio-Internal-Server-Side-Encryption-Sealed-Key".to_string(),
+                "sealed".to_string(),
+            )])),
+            ..Default::default()
+        };
+
+        assert!(object.is_encrypted());
+    }
+
    #[test]
    fn versions_after_marker_handles_null_version_marker() {
        let first_version = Uuid::parse_str("11111111-2222-3333-4444-555555555555").unwrap();
@@ -46,6 +46,7 @@ use crate::bucket::metadata_sys::BucketMetadataSys;
 use crate::bucket::replication::{DynReplicationPool, ReplicationStats};
 use crate::disk::DiskStore;
 use crate::layout::endpoints::{EndpointServerPools, SetupType};
+use crate::object_api::ObjectEncryptionResolver;
 use crate::services::event_notification::EventNotifier;
 use crate::services::tier::tier::TierConfigMgr;
 use rustfs_lock::{GlobalLockManager, get_global_lock_manager};
@@ -159,6 +160,8 @@ pub struct InstanceContext {
    /// workers (scanner/heal/tier/lifecycle) without touching another instance.
    /// Replaces the process-global cancel-token static.
    background_cancel_token: OnceLock<CancellationToken>,
+    /// Resolves object-encryption material at the application boundary.
+    object_encryption_resolver: OnceLock<Arc<dyn ObjectEncryptionResolver>>,
    tier_delete_journal_recovery_stores: std::sync::Mutex<HashSet<Uuid>>,
    transition_transaction_recovery_stores: std::sync::Mutex<HashSet<Uuid>>,
    #[cfg(test)]
@@ -197,6 +200,7 @@ impl InstanceContext {
            local_disk_set_drives: Arc::new(RwLock::new(Vec::new())),
            bucket_metadata_sys: std::sync::Mutex::new(None),
            background_cancel_token: OnceLock::new(),
+            object_encryption_resolver: OnceLock::new(),
            tier_delete_journal_recovery_stores: std::sync::Mutex::new(HashSet::new()),
            transition_transaction_recovery_stores: std::sync::Mutex::new(HashSet::new()),
            #[cfg(test)]
@@ -209,6 +213,19 @@ impl InstanceContext {
        self.lock_manager.clone()
    }

+    /// Install the application-owned object-encryption resolver once.
+    pub fn set_object_encryption_resolver(
+        &self,
+        resolver: Arc<dyn ObjectEncryptionResolver>,
+    ) -> Result<(), Arc<dyn ObjectEncryptionResolver>> {
+        self.object_encryption_resolver.set(resolver)
+    }
+
+    /// Return the configured object-encryption resolver, if startup installed one.
+    pub fn object_encryption_resolver(&self) -> Option<&dyn ObjectEncryptionResolver> {
+        self.object_encryption_resolver.get().map(Arc::as_ref)
+    }
+
    /// Set this instance's S3 region.
    ///
    /// Write-once: panics on a second write, preserving the startup fail-fast
@@ -27,7 +27,7 @@ use crate::{
    bucket::replication::{DynReplicationPool, ReplicationStats},
    config::{get_global_storage_class, get_global_storage_class_snapshot, set_global_storage_class, storageclass},
    disk::{DiskAPI, DiskOption, DiskStore, new_disk},
-    error::Result,
+    error::{Error, Result},
    layout::endpoints::{EndpointServerPools, SetupType},
    runtime::global::{
        GLOBAL_BOOT_TIME, GLOBAL_LIFECYCLE_SYS, GLOBAL_LOCAL_NODE_NAME_FALLBACK, GLOBAL_ROOT_DISK_THRESHOLD,
@@ -46,7 +46,6 @@ use crate::{
 use rustfs_concurrency::WorkloadAdmissionSnapshotProvider;
 use rustfs_config::server_config::{Config, get_global_server_config, set_global_server_config};
 use rustfs_io_metrics::internode_metrics::global_internode_metrics;
-use rustfs_kms::{ObjectEncryptionService, get_global_encryption_service};
 use rustfs_lock::client::LockClient;
 use s3s::dto::BucketLifecycleConfiguration;
 use s3s::region::Region;
@@ -105,10 +104,6 @@ pub(crate) fn record_erasure_write_quorum_failure(stage: &'static str, dominant_
    global_internode_metrics().record_erasure_write_quorum_failure(stage, dominant_error);
 }

-pub(crate) async fn object_encryption_service() -> Option<Arc<ObjectEncryptionService>> {
-    get_global_encryption_service().await
-}
-
 pub fn object_store_handle() -> Option<Arc<ECStore>> {
    resolve_object_store_handle()
 }
@@ -417,14 +412,14 @@ pub(crate) async fn clear_local_disk_id_map_for_test() {
    local_disk_id_map_handle().write().await.clear();
 }

-pub(crate) async fn record_local_disk_id(instance_ctx: &Arc<InstanceContext>, disk_id: Uuid, endpoint: String) {
-    instance_ctx.local_disk_id_map().write().await.insert(disk_id, endpoint);
-}
-
 pub(crate) async fn replace_local_disk_id(previous: Option<Uuid>, current: Option<Uuid>, endpoint: String) {
    let id_map = local_disk_id_map_handle();
    let mut disk_id_map = id_map.write().await;
-    if let Some(previous_id) = previous {
+    if let Some(previous_id) = previous
+        && disk_id_map
+            .get(&previous_id)
+            .is_some_and(|registered_endpoint| registered_endpoint == &endpoint)
+    {
        disk_id_map.remove(&previous_id);
    }
    if let Some(current_id) = current {
@@ -432,6 +427,53 @@ pub(crate) async fn replace_local_disk_id(previous: Option<Uuid>, current: Optio
    }
 }

+pub(crate) async fn reconcile_local_disk_ids(
+    instance_ctx: &InstanceContext,
+    pool_endpoints: &[String],
+    selected: &[(Uuid, String)],
+) {
+    let pool_endpoints = pool_endpoints.iter().map(String::as_str).collect::<HashSet<_>>();
+    let disk_id_map = instance_ctx.local_disk_id_map();
+    let mut disk_ids = disk_id_map.write().await;
+    disk_ids.retain(|_, registered_endpoint| !pool_endpoints.contains(registered_endpoint.as_str()));
+    disk_ids.extend(selected.iter().cloned());
+}
+
+pub(crate) async fn quarantine_local_disks(instance_ctx: &InstanceContext, endpoints: &[Endpoint]) -> Result<()> {
+    let slots = endpoints
+        .iter()
+        .map(|endpoint| {
+            Ok((
+                usize::try_from(endpoint.pool_idx).map_err(|_| Error::CorruptedFormat)?,
+                usize::try_from(endpoint.set_idx).map_err(|_| Error::CorruptedFormat)?,
+                usize::try_from(endpoint.disk_idx).map_err(|_| Error::CorruptedFormat)?,
+            ))
+        })
+        .collect::<Result<Vec<_>>>()?;
+
+    let local_disk_map = instance_ctx.local_disk_map();
+    let mut local_disks = local_disk_map.write().await;
+    for endpoint in endpoints {
+        local_disks.insert(endpoint.to_string(), None);
+    }
+    drop(local_disks);
+
+    let set_drives = instance_ctx.local_disk_set_drives();
+    let mut local_set_drives = set_drives.write().await;
+    if local_set_drives.is_empty() {
+        return Ok(());
+    }
+    for (pool_idx, set_idx, disk_idx) in slots {
+        let disk = local_set_drives
+            .get_mut(pool_idx)
+            .and_then(|sets| sets.get_mut(set_idx))
+            .and_then(|disks| disks.get_mut(disk_idx))
+            .ok_or(Error::CorruptedFormat)?;
+        *disk = None;
+    }
+    Ok(())
+}
+
 pub(crate) async fn record_local_disks(instance_ctx: &Arc<InstanceContext>, disks: Vec<DiskStore>) {
    let map = instance_ctx.local_disk_map();
    let mut global_local_disk_map = map.write().await;
@@ -558,10 +600,14 @@ pub(crate) async fn init_tier_config_mgr(store: Arc<ECStore>) -> Result<()> {

 #[cfg(test)]
 mod tests {
-    use super::{LockRegistry, local_node_name, set_local_node_name};
+    use super::{
+        LockRegistry, clear_local_disk_id_map_for_test, local_disk_path_by_id, local_node_name, reconcile_local_disk_ids,
+        replace_local_disk_id, set_local_node_name,
+    };
    use crate::disk::endpoint::Endpoint;
    use rustfs_lock::{LocalClient, LockClient};
    use std::{collections::HashMap, sync::Arc};
+    use uuid::Uuid;

    fn url_endpoint(raw: &str) -> Endpoint {
        Endpoint {
@@ -607,4 +653,78 @@ mod tests {

        assert_eq!(observed, next);
    }
+
+    #[tokio::test]
+    #[serial_test::serial]
+    async fn clearing_a_stale_disk_id_does_not_remove_another_endpoint() {
+        clear_local_disk_id_map_for_test().await;
+        let disk_id = Uuid::new_v4();
+        replace_local_disk_id(None, Some(disk_id), "endpoint-a".to_string()).await;
+
+        replace_local_disk_id(Some(disk_id), None, "endpoint-b".to_string()).await;
+
+        assert_eq!(local_disk_path_by_id(&disk_id).await, Some("endpoint-a".to_string()));
+        clear_local_disk_id_map_for_test().await;
+    }
+
+    #[tokio::test]
+    #[serial_test::serial]
+    async fn reconciling_pool_disk_ids_preserves_other_endpoints() {
+        let instance_ctx = Arc::new(crate::runtime::instance::InstanceContext::new());
+        let process_ctx = crate::runtime::global::current_ctx();
+        let bootstrap_ctx = crate::runtime::instance::bootstrap_ctx();
+        let retained_id = Uuid::new_v4();
+        let removed_id = Uuid::new_v4();
+        let selected_id = Uuid::new_v4();
+        let process_sentinel = Uuid::new_v4();
+        let bootstrap_sentinel = Uuid::new_v4();
+        instance_ctx.local_disk_id_map().write().await.extend([
+            (retained_id, "endpoint-a".to_string()),
+            (removed_id, "endpoint-b".to_string()),
+        ]);
+        process_ctx
+            .local_disk_id_map()
+            .write()
+            .await
+            .insert(process_sentinel, "endpoint-b".to_string());
+        bootstrap_ctx
+            .local_disk_id_map()
+            .write()
+            .await
+            .insert(bootstrap_sentinel, "endpoint-b".to_string());
+
+        reconcile_local_disk_ids(
+            &instance_ctx,
+            &["endpoint-b".to_string(), "endpoint-c".to_string()],
+            &[(selected_id, "endpoint-c".to_string())],
+        )
+        .await;
+
+        let disk_ids = instance_ctx.local_disk_id_map();
+        let disk_ids = disk_ids.read().await;
+        assert_eq!(disk_ids.get(&retained_id).map(String::as_str), Some("endpoint-a"));
+        assert_eq!(disk_ids.get(&removed_id), None);
+        assert_eq!(disk_ids.get(&selected_id).map(String::as_str), Some("endpoint-c"));
+        drop(disk_ids);
+        assert_eq!(
+            process_ctx
+                .local_disk_id_map()
+                .read()
+                .await
+                .get(&process_sentinel)
+                .map(String::as_str),
+            Some("endpoint-b")
+        );
+        assert_eq!(
+            bootstrap_ctx
+                .local_disk_id_map()
+                .read()
+                .await
+                .get(&bootstrap_sentinel)
+                .map(String::as_str),
+            Some("endpoint-b")
+        );
+        process_ctx.local_disk_id_map().write().await.remove(&process_sentinel);
+        bootstrap_ctx.local_disk_id_map().write().await.remove(&bootstrap_sentinel);
+    }
 }
@@ -337,6 +337,15 @@ pub struct NotificationPeerErr {
    pub err: Option<Error>,
 }

+/// One peer's answer to a KMS configuration fingerprint probe.
+pub struct PeerKmsConfigFingerprint {
+    pub host: String,
+    /// `None` when the peer has no KMS configuration of its own, or could not
+    /// be asked at all, in which case `err` carries the reason.
+    pub fingerprint: Option<String>,
+    pub err: Option<Error>,
+}
+
 fn notification_peer_result<T>(host: String, result: Result<T>) -> NotificationPeerErr {
    NotificationPeerErr { host, err: result.err() }
 }
@@ -518,6 +527,47 @@ impl NotificationSys {
        self.signal_dynamic_config(sub_sys, false).await
    }

+    /// Ask every peer to re-read the cluster-persisted KMS configuration.
+    ///
+    /// Best-effort by contract: the caller has already switched locally, so a
+    /// peer that fails is reported rather than rolled back. Peers built before
+    /// the KMS subsystem existed reject the signal with an explicit error.
+    pub async fn reload_kms_config(&self) -> Vec<NotificationPeerErr> {
+        self.reload_dynamic_config(crate::cluster::rpc::KMS_SIGNAL_SUBSYSTEM).await
+    }
+
+    /// Collect the KMS configuration fingerprint each peer is running.
+    ///
+    /// A peer whose build predates the KMS subsystem rejects the probe, so it
+    /// is reported as an error rather than silently agreeing with this node.
+    pub async fn kms_config_fingerprints(&self) -> Vec<PeerKmsConfigFingerprint> {
+        let mut futures = Vec::with_capacity(self.peer_clients.len());
+        for client in self.peer_clients.iter() {
+            futures.push(async move {
+                let Some(client) = client else {
+                    return PeerKmsConfigFingerprint {
+                        host: String::new(),
+                        fingerprint: None,
+                        err: Some(Error::other("peer is not reachable")),
+                    };
+                };
+                match client.kms_config_fingerprint().await {
+                    Ok(fingerprint) => PeerKmsConfigFingerprint {
+                        host: client.host.to_string(),
+                        fingerprint,
+                        err: None,
+                    },
+                    Err(e) => PeerKmsConfigFingerprint {
+                        host: client.host.to_string(),
+                        fingerprint: None,
+                        err: Some(e),
+                    },
+                }
+            });
+        }
+        join_all(futures).await
+    }
+
    pub async fn refresh_config_snapshot(&self) -> Vec<NotificationPeerErr> {
        let mut futures = Vec::with_capacity(self.peer_clients.len());
        for client in self.peer_clients.iter() {
@@ -2044,15 +2094,10 @@ fn synthesized_disks(host: &str, endpoints: &EndpointServerPools, state: ItemSta
 /// Whether `peer_host` refers to the same node as an endpoint whose
 /// `host_port()` is `ep_host_port`.
 ///
-/// `PeerRestClient::host` is an `XHost`, which resolves names to an address on
-/// construction (`hosts_sorted` -> `XHost::try_from` -> `to_socket_addrs`), so
-/// `peer_host` is the resolved `IP:port`. An endpoint's `host_port()`, however,
-/// is `url.host():port` — still the raw `hostname:port` on hostname-based
-/// deployments. A plain string compare therefore misses on hostname clusters,
-/// leaving the synthesized/degraded drive list empty and `unknownDisks` at 0
-/// (rustfs/rustfs#4607 follow-up). Compare directly first (fast path / IP
-/// deployments), then canonicalize the endpoint side through the same `XHost`
-/// resolution and compare again.
+/// Current topology clients preserve the endpoint `hostname:port`, so the
+/// direct comparison is the normal path. The resolution fallback keeps
+/// compatibility with older or manually constructed clients whose `XHost`
+/// contains a resolved `IP:port` (rustfs/rustfs#4607 follow-up).
 fn endpoint_host_matches(peer_host: &str, ep_host_port: &str) -> bool {
    if peer_host == ep_host_port {
        return true;
@@ -72,6 +72,7 @@ use crate::{
    cluster::rpc::peer_rest_client::{PeerRestClient, PeerTierMutationState},
    config::com::{CONFIG_PREFIX, read_config, read_config_with_metadata},
    disk::{MIGRATING_META_BUCKET, RUSTFS_META_BUCKET},
+    layout::endpoints::EndpointServerPools,
    object_api::{GetObjectReader, ObjectInfo, ObjectOptions, PutObjReader},
    runtime::sources as runtime_sources,
    set_disk::get_lock_acquire_timeout,
@@ -904,14 +905,17 @@ async fn remote_tier_mutation_peers() -> io::Result<Vec<Arc<dyn TierMutationPeer
    let Some(endpoints) = runtime_sources::endpoint_pools() else {
        return Err(tier_mutation_replay_error("cluster endpoint topology is not initialized"));
    };
-    let remote_host_count = endpoints.hosts_sorted().iter().flatten().count();
-    let (peers, _) = PeerRestClient::new_clients(endpoints).await;
+    remote_tier_mutation_peers_from_topology(endpoints).await
+}
+
+async fn remote_tier_mutation_peers_from_topology(endpoints: EndpointServerPools) -> io::Result<Vec<Arc<dyn TierMutationPeer>>> {
+    let (peers, _, remote_topology_hosts) = PeerRestClient::new_clients_with_topology(endpoints).await;
    let peers = peers
        .into_iter()
        .flatten()
        .map(|peer| Arc::new(peer) as Arc<dyn TierMutationPeer>)
        .collect::<Vec<_>>();
-    ensure_complete_tier_mutation_commit_peer_set(peers.len(), remote_host_count)?;
+    ensure_complete_tier_mutation_commit_peer_set(peers.len(), remote_topology_hosts.len())?;
    Ok(peers)
 }

@@ -4307,6 +4311,34 @@ fn tier_config_not_initialized_error(operation: &str) -> std::io::Error {
 #[cfg(test)]
 mod tests {
    use super::*;
+    use crate::layout::{
+        endpoint::Endpoint,
+        endpoints::{Endpoints, PoolEndpoints, SetupType},
+    };
+
+    struct SetupTypeGuard {
+        previous: SetupType,
+    }
+
+    impl SetupTypeGuard {
+        async fn switch_to(next: SetupType) -> Self {
+            let previous = runtime_sources::current_setup_type().await;
+            runtime_sources::set_setup_type(next).await;
+            Self { previous }
+        }
+    }
+
+    impl Drop for SetupTypeGuard {
+        fn drop(&mut self) {
+            let previous = self.previous.clone();
+            let handle = tokio::runtime::Handle::current();
+            tokio::task::block_in_place(|| {
+                handle.block_on(async move {
+                    runtime_sources::set_setup_type(previous).await;
+                });
+            });
+        }
+    }

    fn build_s3_tier(name: &str) -> TierConfig {
        TierConfig {
@@ -6354,6 +6386,42 @@ mod tests {
        assert!(err.to_string().contains("without peer commit clients"), "{err}");
    }

+    #[tokio::test(flavor = "multi_thread")]
+    #[serial_test::serial]
+    async fn tier_mutation_peer_composition_preserves_unresolved_topology_slots() {
+        let mut endpoints = Vec::new();
+        for disk_index in 0..4 {
+            let mut endpoint = Endpoint::try_from(format!("http://rustfs-{disk_index}.invalid:9000/data{disk_index}").as_str())
+                .expect("unresolved topology endpoint should parse without DNS");
+            endpoint.is_local = disk_index == 0;
+            endpoint.set_pool_index(0);
+            endpoint.set_set_index(0);
+            endpoint.set_disk_index(disk_index);
+            endpoints.push(endpoint);
+        }
+        let topology = EndpointServerPools::from(vec![PoolEndpoints {
+            legacy: false,
+            set_count: 1,
+            drives_per_set: 4,
+            endpoints: Endpoints::from(endpoints),
+            cmd_line: "unresolved-tier-mutation-topology".to_string(),
+            platform: "test".to_string(),
+        }]);
+        let _setup_type_guard = SetupTypeGuard::switch_to(SetupType::DistErasure).await;
+
+        let peers = remote_tier_mutation_peers_from_topology(topology)
+            .await
+            .expect("every unresolved remote topology slot should retain a tier mutation client");
+        assert_eq!(
+            peers.iter().map(|peer| peer.peer_label()).collect::<Vec<_>>(),
+            vec![
+                "http://rustfs-1.invalid:9000".to_string(),
+                "http://rustfs-2.invalid:9000".to_string(),
+                "http://rustfs-3.invalid:9000".to_string(),
+            ]
+        );
+    }
+
    #[tokio::test]
    async fn coordinator_fanout_prepare_failure_aborts_prepared_peers_without_cas() {
        let manager = TierConfigMgr::new();
@@ -505,9 +505,7 @@ impl SetDisks {
    }

    fn file_info_has_encryption_metadata(meta: &FileInfo) -> bool {
-        meta.metadata
-            .keys()
-            .any(|name| http::is_encryption_metadata_key(name) || http::is_sse_header(name))
+        meta.metadata.keys().any(|name| http::is_object_encryption_marker(name))
    }

    fn starts_with_ignore_ascii_case(value: &str, prefix: &str) -> bool {
@@ -110,7 +110,10 @@ use crate::{
    object_api::{GetObjectReader, ObjectInfo, PutObjReader},
    // event::name::EventName,
    services::event_notification::{EventArgs, send_event},
-    store::init_format::{get_format_erasure_in_quorum, load_format_erasure, load_format_erasure_all, save_format_file},
+    store::init_format::{
+        formats_match_reference_slots, get_format_erasure_in_quorum, load_format_erasure, load_format_erasure_all,
+        save_format_file,
+    },
 };
 use bytes::Bytes;
 use bytesize::ByteSize;
@@ -144,15 +147,17 @@ use rustfs_object_capacity::capacity_scope::{
    CapacityScope, CapacityScopeDisk, current_dirty_generation, record_capacity_scope, record_global_dirty_scope,
 };
 use rustfs_s3_types::EventName;
+#[cfg(test)]
+use rustfs_utils::http::SSEC_ALGORITHM_HEADER;
 use rustfs_utils::http::headers::AMZ_OBJECT_TAGGING;
 use rustfs_utils::http::headers::AMZ_STORAGE_CLASS;
 use rustfs_utils::http::headers::{
    CACHE_CONTROL, CONTENT_DISPOSITION, CONTENT_ENCODING, CONTENT_LANGUAGE, CONTENT_TYPE, EXPIRES, HeaderExt as _,
 };
 use rustfs_utils::http::{
-    SSEC_ALGORITHM_HEADER, SSEC_KEY_HEADER, SSEC_KEY_MD5_HEADER, SUFFIX_ACTUAL_OBJECT_SIZE_CAP, SUFFIX_ACTUAL_SIZE,
-    SUFFIX_COMPRESSION, SUFFIX_COMPRESSION_SIZE, SUFFIX_REPLICATION_SSEC_CRC, SUFFIX_RESTORE_OPERATION_ID, contains_key_str,
-    get_header_map, get_str, insert_str, is_encryption_metadata_key, remove_header_map,
+    SUFFIX_ACTUAL_OBJECT_SIZE_CAP, SUFFIX_ACTUAL_SIZE, SUFFIX_COMPRESSION, SUFFIX_COMPRESSION_SIZE, SUFFIX_REPLICATION_SSEC_CRC,
+    SUFFIX_RESTORE_OPERATION_ID, contains_key_str, get_header_map, get_str, insert_str, is_object_encryption_marker,
+    remove_header_map,
 };
 use rustfs_utils::{
    HashAlgorithm,
@@ -667,10 +672,7 @@ pub(crate) fn strip_internal_multipart_metadata(metadata: &mut HashMap<String, S
 }

 fn should_persist_encryption_original_size(metadata: &HashMap<String, String>) -> bool {
-    metadata.keys().any(|key| is_encryption_metadata_key(key))
-        || metadata.contains_key(SSEC_ALGORITHM_HEADER)
-        || metadata.contains_key(SSEC_KEY_HEADER)
-        || metadata.contains_key(SSEC_KEY_MD5_HEADER)
+    metadata.keys().any(|key| is_object_encryption_marker(key))
 }

 /// Per-set memoized capacity dirty scope.
@@ -4712,6 +4714,7 @@ mod tests {
    use crate::layout::endpoints::SetupType;
    use crate::object_api::BLOCK_SIZE_V2;
    use crate::object_api::ObjectInfo;
+    use crate::set_disk::core::io_primitives::rename_fanout_barrier;
    use crate::storage_api_contracts::{
        heal::HealOperations as _, lifecycle::TransitionedObject, list::ListOperations as _, multipart::CompletePart,
        namespace::NamespaceLocking as _, object::ObjectIO as _, object::ObjectOperations as _,
@@ -9563,6 +9566,15 @@ mod tests {
        make_local_bucket_test_set_disks_with_drive_count(2).await
    }

+    fn assert_exclusive_object_lock_held(set_disks: &SetDisks, bucket: &str, object: &str) {
+        let lock = set_disks
+            .local_lock_manager_for_test()
+            .get_lock_info(&ObjectKey::new(bucket, object))
+            .expect("object lock should be visible while rename is paused");
+        assert!(matches!(lock.mode, rustfs_lock::LockMode::Exclusive));
+        assert_eq!(lock.owner.as_ref(), set_disks.locker_owner.as_str());
+    }
+
    async fn make_local_bucket_test_set_disks_with_drive_count(drive_count: usize) -> Arc<SetDisks> {
        let format = FormatV3::new(1, drive_count);
        let mut endpoints = Vec::new();
@@ -9597,7 +9609,9 @@ mod tests {
            disks.push(Some(disk));
        }

-        let set_disks = SetDisks::new(
+        let instance_ctx = Arc::new(InstanceContext::new());
+        instance_ctx.update_erasure_type(SetupType::Erasure).await;
+        let set_disks = SetDisks::new_with_instance_ctx(
            "test-owner".to_string(),
            Arc::new(RwLock::new(disks)),
            drive_count,
@@ -9607,6 +9621,7 @@ mod tests {
            endpoints,
            format,
            Vec::new(),
+            instance_ctx,
        )
        .await;
        set_disks.set_test_storage_class_config(
@@ -10260,6 +10275,216 @@ mod tests {
        ));
    }

+    #[tokio::test]
+    async fn conditional_replace_holds_object_lock_through_rename() {
+        let set_disks = make_local_bucket_test_set_disks().await;
+        let bucket = "bucket-conditional-replace-fence";
+        let object = "config/conditional-replace.json";
+        set_disks
+            .make_bucket(bucket, &MakeBucketOptions::default())
+            .await
+            .expect("bucket should be created");
+
+        let mut initial_reader = PutObjReader::from_vec(b"initial config".to_vec());
+        let initial = set_disks
+            .put_object(
+                bucket,
+                object,
+                &mut initial_reader,
+                &ObjectOptions {
+                    no_lock: true,
+                    ..Default::default()
+                },
+            )
+            .await
+            .expect("initial config should be written");
+        let initial_etag = initial.etag.expect("initial config should have an ETag");
+
+        let barrier = rename_fanout_barrier::arm(object, 0, rename_fanout_barrier::PHASE_RENAME);
+        let writer_store = set_disks.clone();
+        let expected_etag = initial_etag.clone();
+        let writer = tokio::spawn(async move {
+            let mut reader = PutObjReader::from_vec(b"replacement config".to_vec());
+            writer_store
+                .put_object(
+                    bucket,
+                    object,
+                    &mut reader,
+                    &ObjectOptions {
+                        preserve_etag: Some("replacement-etag".to_string()),
+                        http_preconditions: Some(HTTPPreconditions {
+                            if_match: Some(expected_etag),
+                            ..Default::default()
+                        }),
+                        ..Default::default()
+                    },
+                )
+                .await
+        });
+
+        tokio::time::timeout(std::time::Duration::from_secs(30), barrier.wait_until_paused())
+            .await
+            .expect("conditional replace should reach the rename barrier");
+        assert_exclusive_object_lock_held(&set_disks, bucket, object);
+        barrier.release();
+        writer
+            .await
+            .expect("conditional writer task should finish")
+            .expect("matching conditional replace should commit");
+        assert!(
+            set_disks
+                .local_lock_manager_for_test()
+                .get_lock_info(&ObjectKey::new(bucket, object))
+                .is_none(),
+            "conditional replace should release the object lock after commit"
+        );
+        let contender = set_disks
+            .new_ns_lock(bucket, object)
+            .await
+            .expect("contender namespace lock should be created");
+        let contender_guard = contender
+            .get_write_lock(std::time::Duration::from_secs(30))
+            .await
+            .expect("contender should acquire after conditional replace commits");
+        drop(contender_guard);
+
+        let mut stale_reader = PutObjReader::from_vec(b"stale config".to_vec());
+        let err = set_disks
+            .put_object(
+                bucket,
+                object,
+                &mut stale_reader,
+                &ObjectOptions {
+                    http_preconditions: Some(HTTPPreconditions {
+                        if_match: Some(initial_etag),
+                        ..Default::default()
+                    }),
+                    ..Default::default()
+                },
+            )
+            .await
+            .expect_err("the old ETag must fail after the fenced replacement commits");
+        assert_eq!(err, StorageError::PreconditionFailed);
+    }
+
+    #[tokio::test]
+    async fn repeated_body_write_keeps_etag_but_changes_data_dir_generation() {
+        let set_disks = make_local_bucket_test_set_disks().await;
+        let bucket = "bucket-write-generation";
+        let object = "config/write-generation.json";
+        let body = b"identical config body".to_vec();
+        set_disks
+            .make_bucket(bucket, &MakeBucketOptions::default())
+            .await
+            .expect("bucket should be created");
+
+        let mut first_reader = PutObjReader::from_vec(body.clone());
+        let first = set_disks
+            .put_object(
+                bucket,
+                object,
+                &mut first_reader,
+                &ObjectOptions {
+                    no_lock: true,
+                    ..Default::default()
+                },
+            )
+            .await
+            .expect("first config body should be written");
+        let mut second_reader = PutObjReader::from_vec(body);
+        let second = set_disks
+            .put_object(
+                bucket,
+                object,
+                &mut second_reader,
+                &ObjectOptions {
+                    no_lock: true,
+                    ..Default::default()
+                },
+            )
+            .await
+            .expect("identical config body should be rewritten");
+
+        assert_eq!(first.etag, second.etag, "content ETag should expose the ABA collision");
+        assert_ne!(first.data_dir, second.data_dir, "each committed body write needs a unique generation");
+        assert!(first.data_dir.is_some() && second.data_dir.is_some());
+    }
+
+    #[tokio::test]
+    async fn conditional_create_holds_object_lock_through_rename() {
+        let set_disks = make_local_bucket_test_set_disks().await;
+        let bucket = "bucket-conditional-create-fence";
+        let object = "config/conditional-create.json";
+        set_disks
+            .make_bucket(bucket, &MakeBucketOptions::default())
+            .await
+            .expect("bucket should be created");
+
+        let barrier = rename_fanout_barrier::arm(object, 0, rename_fanout_barrier::PHASE_RENAME);
+        let writer_store = set_disks.clone();
+        let writer = tokio::spawn(async move {
+            let mut reader = PutObjReader::from_vec(b"created config".to_vec());
+            writer_store
+                .put_object(
+                    bucket,
+                    object,
+                    &mut reader,
+                    &ObjectOptions {
+                        http_preconditions: Some(HTTPPreconditions {
+                            if_none_match: Some("*".to_string()),
+                            ..Default::default()
+                        }),
+                        ..Default::default()
+                    },
+                )
+                .await
+        });
+
+        tokio::time::timeout(std::time::Duration::from_secs(30), barrier.wait_until_paused())
+            .await
+            .expect("conditional create should reach the rename barrier");
+        assert_exclusive_object_lock_held(&set_disks, bucket, object);
+        barrier.release();
+        writer
+            .await
+            .expect("conditional writer task should finish")
+            .expect("first conditional create should commit");
+        assert!(
+            set_disks
+                .local_lock_manager_for_test()
+                .get_lock_info(&ObjectKey::new(bucket, object))
+                .is_none(),
+            "conditional create should release the object lock after commit"
+        );
+        let contender = set_disks
+            .new_ns_lock(bucket, object)
+            .await
+            .expect("contender namespace lock should be created");
+        let contender_guard = contender
+            .get_write_lock(std::time::Duration::from_secs(30))
+            .await
+            .expect("contender should acquire after conditional create commits");
+        drop(contender_guard);
+
+        let mut duplicate_reader = PutObjReader::from_vec(b"duplicate config".to_vec());
+        let err = set_disks
+            .put_object(
+                bucket,
+                object,
+                &mut duplicate_reader,
+                &ObjectOptions {
+                    http_preconditions: Some(HTTPPreconditions {
+                        if_none_match: Some("*".to_string()),
+                        ..Default::default()
+                    }),
+                    ..Default::default()
+                },
+            )
+            .await
+            .expect_err("a second create-only write must not replace the committed config");
+        assert_eq!(err, StorageError::PreconditionFailed);
+    }
+
    #[tokio::test]
    async fn set_level_if_none_match_fails_closed_without_read_quorum() {
        let set_disks = make_local_bucket_test_set_disks_with_drive_count(4).await;
@@ -1373,11 +1373,24 @@ impl crate::storage_api_contracts::heal::HealOperations for SetDisks {
    async fn heal_format(&self, dry_run: bool) -> Result<(HealResultItem, Option<Error>)> {
        let disks = self.disks.read().await.clone();
        let (formats, errs) = load_format_erasure_all(&disks, true).await;
-        let ref_format = match get_format_erasure_in_quorum(&formats) {
-            Ok(format) => format,
+        if errs.iter().any(|err| {
+            matches!(
+                err,
+                Some(DiskError::InconsistentDisk | DiskError::CorruptedFormat | DiskError::CorruptedBackend)
+            )
+        }) {
+            return Ok((HealResultItem::default(), Some(StorageError::CorruptedFormat)));
+        }
+        let slot_offset = self
+            .set_index
+            .checked_mul(self.set_drive_count)
+            .ok_or_else(|| Error::other("erasure set slot offset overflow"))?;
+        let ref_format = match get_format_erasure_in_quorum(&formats, slot_offset) {
+            Ok(format) if format.shared_identity() == self.format.shared_identity() => format,
+            Ok(_) => return Ok((HealResultItem::default(), Some(StorageError::CorruptedFormat))),
            Err(err) => {
                let can_use_cached_layout = count_errs(&errs, &DiskError::UnformattedDisk) > 0
-                    && formats.iter().flatten().all(|format| self.format.check_other(format).is_ok())
+                    && formats_match_reference_slots(&formats, &self.format, slot_offset)
                    && errs
                        .iter()
                        .all(|err| err.is_none() || matches!(err, Some(DiskError::UnformattedDisk)));
@@ -1388,6 +1401,9 @@ impl crate::storage_api_contracts::heal::HealOperations for SetDisks {
                }
            }
        };
+        if !formats_match_reference_slots(&formats, &ref_format, slot_offset) {
+            return Ok((HealResultItem::default(), Some(StorageError::CorruptedFormat)));
+        }

        let endpoints = crate::layout::endpoints::Endpoints::from(self.set_endpoints.clone());
        let before_drives = crate::layout::set_heal::formats_to_drives_info(&endpoints, &formats, &errs);
@@ -1543,11 +1559,16 @@ mod heal_result_report_tests {
    use crate::disk::error::DiskError;
    use crate::disk::format::FormatV3;
    use crate::disk::{DiskAPI as _, DiskOption, DiskStore, RUSTFS_META_TMP_BUCKET, ReadOptions, new_disk};
+    use crate::error::Error;
    use crate::object_api::{ObjectOptions, PutObjReader};
    use crate::set_disk::ops::object::hermetic_set_disks_support::hermetic_set_disks_isolated;
    use crate::storage_api_contracts::bucket::{BucketOperations as _, MakeBucketOptions};
+    use crate::storage_api_contracts::heal::HealOperations as _;
    use crate::storage_api_contracts::object::{ObjectIO as _, ObjectOperations as _};
-    use crate::{config::storageclass, store::init_format::save_format_file};
+    use crate::{
+        config::storageclass,
+        store::init_format::{load_format_erasure, save_format_file},
+    };
    use rustfs_common::heal_channel::{DriveState, HealOpts, HealScanMode};
    use rustfs_filemeta::{BLOCK_SIZE_V2, FileInfo, ObjectPartInfo, TRANSITION_COMPLETE};
    use std::sync::Arc;
@@ -1863,6 +1884,44 @@ mod heal_result_report_tests {
        }
    }

+    #[tokio::test]
+    async fn format_heal_cached_layout_rejects_a_disk_from_another_slot() {
+        let mut _temp_dirs = Vec::new();
+        let mut endpoints = Vec::new();
+        let mut disks = Vec::new();
+        for disk_index in 0..3 {
+            let (temp_dir, mut endpoint, disk) = real_disk().await;
+            endpoint.set_pool_index(0);
+            endpoint.set_set_index(0);
+            endpoint.set_disk_index(disk_index);
+            _temp_dirs.push(temp_dir);
+            endpoints.push(endpoint);
+            disks.push(Some(disk));
+        }
+        let set = set_disks_with(disks.clone(), endpoints, 1).await;
+        let mut wrong_slot = set.format.clone();
+        wrong_slot.erasure.this = set.format.erasure.sets[0][1];
+        save_format_file(&disks[0], &Some(wrong_slot))
+            .await
+            .expect("wrong-slot format fixture should be saved");
+        let mut correct_slot = set.format.clone();
+        correct_slot.erasure.this = set.format.erasure.sets[0][2];
+        save_format_file(&disks[2], &Some(correct_slot))
+            .await
+            .expect("correct format fixture should be saved");
+
+        let (_, heal_err) = set
+            .heal_format(false)
+            .await
+            .expect("format heal should report the quorum failure in its result");
+
+        assert!(matches!(heal_err, Some(Error::CorruptedFormat)));
+        let unformatted = load_format_erasure(disks[1].as_ref().expect("second disk should be online"), true)
+            .await
+            .expect_err("a rejected fallback must not format the missing slot");
+        assert_eq!(unformatted, DiskError::UnformattedDisk);
+    }
+
    // Regression for #955: an offline disk must contribute exactly one drive
    // record. Before the fix the offline branch fell through and pushed a second
    // (Corrupt) record for the same disk, so `before/after.drives` grew to
@@ -343,20 +343,23 @@ impl SetDisks {
            }
        };

-        // The drive's format may place it in a different erasure set than this
-        // one. Claiming a misplaced drive into `self.disks` would let two sets
-        // manage the same drive and degrade together, so reject it here
-        // (backlog#799 B19).
-        if set_idx != self.set_index {
+        // Claiming a misplaced drive into `self.disks` would let two slots or
+        // sets manage the same drive and degrade together (backlog#799 B19).
+        if set_idx != self.set_index || self.set_endpoints.get(disk_idx) != Some(ep) {
            warn!(
-                "renew_disk: drive {:?} belongs to set {} but is being renewed on set {}; skipping",
-                ep, set_idx, self.set_index
+                endpoint = %ep,
+                format_set_index = set_idx,
+                format_disk_index = disk_idx,
+                endpoint_pool_index = ep.pool_idx,
+                endpoint_set_index = ep.set_idx,
+                endpoint_disk_index = ep.disk_idx,
+                expected_pool_index = self.pool_index,
+                expected_set_index = self.set_index,
+                "renew_disk rejected a drive whose endpoint and format do not identify the same topology slot"
            );
            return;
        }

-        // Check that the endpoint matches
-
        let _ = new_disk.set_disk_id(Some(fm.erasure.this)).await;
        new_disk.enable_health_check();

@@ -715,6 +718,108 @@ mod tests {
        drop(temp_dirs);
    }

+    #[tokio::test]
+    async fn renew_disk_rejects_a_format_from_another_slot_or_cluster() {
+        let disk_count = 3;
+        let format = FormatV3::new(1, disk_count);
+        let mut temp_dirs = Vec::with_capacity(disk_count);
+        let mut endpoints = Vec::with_capacity(disk_count);
+        let mut fixture_disks = Vec::with_capacity(disk_count);
+
+        for disk_idx in 0..disk_count {
+            let (temp_dir, endpoint, disk) = make_formatted_local_disk(disk_idx, &format).await;
+            temp_dirs.push(temp_dir);
+            endpoints.push(endpoint);
+            fixture_disks.push(disk);
+        }
+
+        let set_disks = SetDisks::new(
+            "test-owner".to_string(),
+            Arc::new(RwLock::new(vec![Some(fixture_disks[0].clone()), None, None])),
+            disk_count,
+            disk_count / 2,
+            0,
+            0,
+            endpoints.clone(),
+            format.clone(),
+            Vec::new(),
+        )
+        .await;
+
+        let mut other_cluster_format = format.clone();
+        other_cluster_format.id = Uuid::new_v4();
+        other_cluster_format.erasure.this = format.erasure.sets[0][2];
+        save_format_file(&Some(fixture_disks[2].clone()), &Some(other_cluster_format))
+            .await
+            .expect("other-cluster format should be written for the rejection test");
+
+        set_disks.renew_disk(&endpoints[2]).await;
+
+        let disks = set_disks.get_disks_internal().await;
+        assert_eq!(
+            disks[0]
+                .as_ref()
+                .expect("the canonical first slot must remain attached")
+                .endpoint(),
+            endpoints[0]
+        );
+        assert!(
+            disks[2].is_none(),
+            "a disk from another deployment must remain detached even when its slot UUID matches"
+        );
+
+        let mut correct_format = format.clone();
+        correct_format.erasure.this = format.erasure.sets[0][2];
+        let replacement_disk = new_disk(
+            &endpoints[2],
+            &DiskOption {
+                cleanup: false,
+                health_check: false,
+            },
+        )
+        .await
+        .expect("third endpoint should reopen after other-cluster rejection");
+        save_format_file(&Some(replacement_disk), &Some(correct_format))
+            .await
+            .expect("correct slot format should be restored");
+
+        set_disks.renew_disk(&endpoints[2]).await;
+
+        let disks = set_disks.get_disks_internal().await;
+        assert_eq!(
+            disks[0]
+                .as_ref()
+                .expect("the canonical first slot must remain attached")
+                .endpoint(),
+            endpoints[0]
+        );
+        assert_eq!(disks[2].as_ref().expect("the restored third slot should attach").endpoint(), endpoints[2]);
+
+        let third_disk = disks[2].clone();
+        let mut wrong_slot_format = format.clone();
+        wrong_slot_format.erasure.this = format.erasure.sets[0][0];
+        save_format_file(&third_disk, &Some(wrong_slot_format))
+            .await
+            .expect("wrong-slot format should be written for the rejection test");
+        set_disks.disks.write().await[2] = None;
+
+        let mut misplaced_endpoint = endpoints[2].clone();
+        misplaced_endpoint.set_disk_index(0);
+        set_disks.renew_disk(&misplaced_endpoint).await;
+
+        let disks = set_disks.get_disks_internal().await;
+        assert_eq!(
+            disks[0]
+                .as_ref()
+                .expect("the canonical first slot must remain attached")
+                .endpoint(),
+            endpoints[0]
+        );
+        assert!(disks[2].is_none(), "a disk claiming another endpoint's slot must remain detached");
+
+        drop(temp_dirs);
+    }
+
    // SetDisks split P0 (#816): the borrow handle must mirror the core state and
    // the List operation family must run identically through it.
    #[tokio::test]
@@ -42,6 +42,7 @@ use crate::object_api::{GetObjectBodySource, get_object_body_cache_hook_suppress
 use crate::services::tier::tier::{TierConfigMgr, TierOperationLease};
 use crate::store::ECStore;
 use futures::FutureExt as _;
+use http::HeaderValue;
 use std::future::Future;

 fn erasure_from_file_info(fi: &FileInfo, uses_legacy: bool) -> Result<coding::Erasure> {
@@ -49,6 +50,17 @@ fn erasure_from_file_info(fi: &FileInfo, uses_legacy: bool) -> Result<coding::Er
        .map_err(Error::from)
 }

+async fn get_object_reader_with_context(
+    ctx: &InstanceContext,
+    reader: Box<dyn AsyncRead + Unpin + Send + Sync>,
+    range: Option<HTTPRangeSpec>,
+    object_info: &ObjectInfo,
+    opts: &ObjectOptions,
+    headers: &HeaderMap<HeaderValue>,
+) -> Result<(GetObjectReader, usize, i64)> {
+    GetObjectReader::new_with_resolver(reader, range, object_info, opts, headers, ctx.object_encryption_resolver()).await
+}
+
 /// Length of the full plaintext body when — and only when — this read's output
 /// is exactly the object's complete plaintext, so the app-layer body cache may
 /// serve it in place of the erasure read.
@@ -713,7 +725,8 @@ impl crate::storage_api_contracts::object::ObjectIO for SetDisks {
                            size_bucket,
                        );
                        record_get_object_reader_path_observation(GET_OBJECT_PATH_CODEC_STREAMING, object_class, size_bucket);
-                        let (mut reader, _offset, _length) = GetObjectReader::new(stream, range, &object_info, opts, &h).await?;
+                        let (mut reader, _offset, _length) =
+                            get_object_reader_with_context(&self.ctx, stream, range, &object_info, opts, &h).await?;
                        // Carry the hook probe result so the app layer skips its
                        // now-redundant lookup on the streaming miss path (ODC-16).
                        reader.body_source = body_source;
@@ -745,7 +758,8 @@ impl crate::storage_api_contracts::object::ObjectIO for SetDisks {
        let (rd, wd) = tokio::io::duplex(duplex_buffer_size);
        debug!(bucket, object, duplex_buffer_size, "Created duplex pipe for object data transfer");

-        let (mut reader, offset, length) = GetObjectReader::new(Box::new(rd), range, &object_info, opts, &h).await?;
+        let (mut reader, offset, length) =
+            get_object_reader_with_context(&self.ctx, Box::new(rd), range, &object_info, opts, &h).await?;
        // Carry the hook probe result so the app layer skips its now-redundant
        // lookup on the streaming miss path (ODC-16).
        reader.body_source = body_source;
@@ -4536,6 +4550,61 @@ mod erasure_construction_tests {
    }
 }

+#[cfg(test)]
+mod object_encryption_resolver_wiring_tests {
+    use super::*;
+    use crate::object_api::{EncryptionResolutionError, ObjectEncryptionResolver, ReadEncryptionMaterial, ReadEncryptionRequest};
+    use std::io::Cursor;
+    use std::sync::atomic::{AtomicUsize, Ordering};
+
+    struct CountingResolver {
+        calls: AtomicUsize,
+    }
+
+    #[async_trait::async_trait]
+    impl ObjectEncryptionResolver for CountingResolver {
+        async fn resolve_read_material(
+            &self,
+            _request: ReadEncryptionRequest<'_>,
+        ) -> std::result::Result<Option<ReadEncryptionMaterial>, EncryptionResolutionError> {
+            self.calls.fetch_add(1, Ordering::Relaxed);
+            Ok(None)
+        }
+    }
+
+    #[tokio::test]
+    async fn get_object_reader_forwards_instance_resolver() {
+        let resolver = Arc::new(CountingResolver {
+            calls: AtomicUsize::new(0),
+        });
+        let ctx = InstanceContext::new();
+        assert!(
+            ctx.set_object_encryption_resolver(resolver.clone()).is_ok(),
+            "fresh context should accept resolver"
+        );
+        let object_info = ObjectInfo {
+            bucket: "bucket".to_string(),
+            name: "object".to_string(),
+            size: 1,
+            user_defined: Arc::new(HashMap::from([("x-amz-server-side-encryption".to_string(), "AES256".to_string())])),
+            ..Default::default()
+        };
+
+        let result = get_object_reader_with_context(
+            &ctx,
+            Box::new(Cursor::new(Vec::<u8>::new())),
+            None,
+            &object_info,
+            &ObjectOptions::default(),
+            &HeaderMap::new(),
+        )
+        .await;
+
+        assert!(result.is_err(), "resolver returning no material must fail closed");
+        assert_eq!(resolver.calls.load(Ordering::Relaxed), 1);
+    }
+}
+
 #[cfg(test)]
 pub(in crate::set_disk::ops) mod hermetic_set_disks_support {
    //! Shared hermetic `SetDisks` construction for the ops tests below: the
--- a/Show More
+++ b/Show More