rustfs/docs/operations/tier-ilm-debugging.md

Tier / ILM Transition Debugging Guide

Use this when: a tiered (transitioned) object returns NoSuchVersion or fails to restore, a transition run looks stuck, or you need to inspect xl.meta and trace the versionId sent to the remote tier.

Source of truth: crates/ecstore/src/bucket/lifecycle/bucket_lifecycle_ops.rs (transition/expiry actions, fenced free-version cleanup, and durable-job recovery), crates/ecstore/src/bucket/lifecycle/manual_transition_job.rs (job/task/result records), rustfs/src/admin/handlers/ilm_transition.rs (manual run/status/cancel and transition-transaction reconcile routes), crates/utils/src/http/metadata_compat.rs (dual-key helpers), crates/filemeta/src/filemeta/version.rs (SUFFIX_TRANSITIONED_VERSION_ID read pattern), crates/filemeta/examples/dump_fileinfo.rs.

Code map

Concern	Location
ILM actions (transition_object, expire_transitioned_object, get_transitioned_object_reader, gen_transition_objname)	crates/ecstore/src/bucket/lifecycle/bucket_lifecycle_ops.rs
Erasure-set transition/restore entry points	crates/ecstore/src/set_disk/ and crates/ecstore/src/store/
WarmBackend trait (put/get/remove/in_use)	crates/ecstore/src/services/tier/warm_backend.rs
Per-provider tier backends (S3, MinIO, GCS, Azure, ...)	crates/ecstore/src/services/tier/warm_backend_*.rs
Remote-tier sweep (delete_object_from_remote_tier)	crates/ecstore/src/bucket/lifecycle/tier_sweeper.rs
Persisted free-version scan and re-enqueue after local-first expiry	crates/ecstore/src/bucket/lifecycle/tier_free_version_recovery.rs
Fenced free-version remote delete, local-marker cleanup, and rescan	crates/ecstore/src/bucket/lifecycle/bucket_lifecycle_ops.rs (cleanup_free_version_exact)
Durable manual transition job/task/result records	crates/ecstore/src/bucket/lifecycle/manual_transition_job.rs
Dormant tier validation probe intent format and read-only core inspection	crates/ecstore/src/services/tier/tier_probe_intent.rs
Manual run/status/cancel and transition-transaction reconcile admin routes	rustfs/src/admin/handlers/ilm_transition.rs
ObjectInfo / TransitionedObject types	crates/ecstore/src/object_api/types.rs
FileMeta / FileInfo / version metadata	crates/filemeta/src/
Dual-key internal metadata helpers (insert_bytes / get_bytes)	crates/utils/src/http/metadata_compat.rs

Free-version recovery controls

The dedicated free-version recovery loop is enabled by default and is independent of the data scanner and heal switches. Setting RUSTFS_SCANNER_ENABLED=false does not stop this repair loop. Set RUSTFS_TIER_FREE_VERSION_RECOVERY_ENABLED=false before process startup to disable only the dedicated persisted-marker walk. That setting does not disable lifecycle workers or prevent another scanner path from discovering a free version, and it can leave remote cleanup markers pending for longer, so use it as a break-glass pressure control rather than a cleanup mechanism.

Normal transitioned deletes pass a post-commit receipt directly to the lifecycle queue. The namespace walk is the crash, queue-pressure, mixed-version, and historical-record fallback. It cannot safely skip a bucket merely because that bucket has no current lifecycle rule or the referenced tier was removed: an older xl.meta free-version can still be the only owner of a required remote DELETE.

One background recovery page completes at most 10,000 logical objects across at most 100 buckets and enqueues at most 1,000 recoverable free versions. The scanner can decode one additional object to detect truncation; a continuation marker preserves the first unscanned bucket or the last completely scanned object. Every truncated page and follow-up sweep waits at least 60 seconds after the previous page completes; failed pages back off from 60 seconds to 10 minutes, and complete idle sweeps exponentially back off to 10 minutes with jitter. Individual walks have no fixed total timeout, but inherit the drive walk stall timeout so a large healthy bucket can make progress without recreating the old timeout/restart loop.

The structured lifecycle_worker_state recovery event reports duration_ms, scanned_entries, buckets_scanned, queue counts, truncation, and continuation markers. rustfs_internal_stage_duration_ms{stage="lifecycle_free_version_recovery"} records successful page duration; stage="lifecycle_free_version_recovery_failed" records failures.

Metadata key conventions

Internal metadata is stored under both x-rustfs-internal-<suffix> and x-minio-internal-<suffix> for MinIO interoperability. get_bytes prefers the RustFS key and falls back to the MinIO key.

Suffix	Meaning
transition-status	"complete" when tiered
transitioned-object	tier key path (stored without the tier prefix; get_dest adds it)
transitioned-versionID	Provider version identifier: current exact UTF-8 text, legacy RustFS raw UUID bytes, MinIO's empty unversioned value, or absent for some historical unversioned records. Interpret it only with transitioned-version-state or a live compatibility probe.
transition-tier	tier name
tier-free-versionID	delete-marker version for free-version sweep

Legacy raw UUID values must reject empty, malformed, and nil UUIDs (regression covered in crates/filemeta/src/filemeta/version.rs tests):

get_bytes(&self.meta_sys, SUFFIX_TRANSITIONED_VERSION_ID)
    .and_then(|v| Uuid::from_slice(v.as_slice()).ok())
    .filter(|u| !u.is_nil())
// None for: absent key, wrong-length bytes, nil UUID

transition_version_id == None means only that no usable legacy UUID projection exists; it does not prove the remote bucket's versioning model. Only an explicit KnownDisabled state authorizes ordinary GET/DELETE to omit versionId. A missing state with an absent or empty version key remains Unknown and requires the bounded compatibility probe or the approved reconcile workflow; it never directly authorizes cleanup. A nil UUID (00000000-...) sent as ?versionId= causes NoSuchVersion. Do not use Uuid::from_slice(..).unwrap_or_default() here: it converts an empty metadata value into Uuid::nil(), which is exactly that failure.

Inspect xl.meta directly

cargo build -p rustfs-filemeta --example dump_fileinfo
./target/debug/examples/dump_fileinfo /srv/rustfs/data/disk0/{bucket}/{object}/xl.meta
# Shows: transition_status, transition_tier, transitioned_obj, transition_ver_id

Output	Meaning
transition_ver_id: <none>	No usable legacy UUID projection exists. Inspect transitioned-version-state and the raw compatibility keys; do not infer unversioned semantics.
transition_ver_id: <uuid>	A legacy UUID representation decoded successfully. It is not destructive authority unless the persisted state or reconcile proof establishes the exact remote model.

There is one xl.meta per erasure shard disk ({disk}/{bucket}/{object}/xl.meta); all shards of a healthy object should be identical. dump_versions (same crate) lists every version in a file.

Trace the versionId at runtime

RUST_LOG=rustfs_ecstore::bucket::lifecycle=debug rustfs ...

Log line	Level	Meaning
fetching transitioned object from tier	DEBUG	Emitted before the tier request.
tier GET failed	ERROR	Includes tier_version_id.

If the version keys are empty while transitioned-version-state is absent, the record has the historical MinIO unversioned shape but still remains Unknown; only the compatibility probe or reconcile protocol may prove KnownDisabled. If state is explicitly KnownDisabled, no versionId is sent.

Manual transition run

Manual transition run is an operator trigger for the existing lifecycle transition evaluator. It does not force objects that are not due under the bucket lifecycle rule, and it does not bypass versioning, replication, delete-marker, directory-marker, tier, or in-flight transition checks.

POST /rustfs/admin/v3/ilm/transition/run?bucket=<bucket>&prefix=<prefix>&tier=<tier>&dryRun=true&maxObjects=10000&maxDurationSeconds=30

Parameter	Contract
bucket	Required.
prefix, tier, dryRun	Narrow the run.
mode	enqueue_only by default; set async for a durable background job.
async	Compatibility boolean for selecting durable async mode. It must not conflict with mode.
maxObjects	Defaults to 10000, capped at 100000.
maxDurationSeconds	Optional, capped at 3600; a best-effort budget checked between listed object versions and pages. An in-flight listing call is not cancelled.

In the default enqueue_only mode, the response reports what this bounded scan evaluated and enqueued into the in-memory transition queue. state=completed means the bounded scan reached the end of its current scope without queue pressure or budget truncation; it does not mean every remote tier PUT has completed. state=partial means the run stopped early on maxObjects, maxDurationSeconds, or queue pressure (skipped_queue_full, skipped_queue_closed, or skipped_queue_timeout). Its response omits job endpoints.

With mode=async or async=true, a successful request returns 202 Accepted, mode=durable_job, a UUID job_id, and status/cancel endpoints. Durable mode provides bucket-level persisted admission, restart recovery, a lease-fenced listing checkpoint, task-before-enqueue records, worker-result records, and persisted cancellation. It still delegates each object to the normal lifecycle evaluator and transition transaction; a job never bypasses object eligibility or owns remote deletion.

GET    /rustfs/admin/v3/ilm/transition/jobs/<job-id>
DELETE /rustfs/admin/v3/ilm/transition/jobs/<job-id>

GET returns the durable job state and report. DELETE persists cancel_requested, which stops new scan work for an active executor. Startup recovery reconciles task/results first only when scan_completed = true. An expired job whose scan is incomplete and cancellation is requested is directly CAS-terminalized as cancelled, so its stored counters may be stale; scope release follows as a best-effort exact delete. Non-cancelled recovery instead CAS-takes over the lease, replaces the scope admission, replays pending tasks, and resumes object-version scanning from the persisted token. A conflicting live durable job for the same bucket and run/dry-run class returns the active job and its endpoint. The async endpoint itself does not query a fleet capability gate and a direct request proceeds to durable job creation. Before enabling durable mode across a mixed fleet, caller/operator orchestration must check the manual_transition_jobs runtime capability on every required node and fail closed if any response is unknown or unsupported.

The persisted states, ownership and recovery rules are specified in ../architecture/ilm-tiering-persistence-contracts.md. Terminal job/task/result history currently has no automatic retention bound, so status data remains available until a future protocol-level collector is defined.

Recommended operator flow (external rc CLI):

rc admin ilm transition run local/mybucket --prefix logs/ --tier cold --dry-run --max-objects 1000 --max-duration-seconds 30
rc admin ilm transition run local/mybucket --prefix logs/ --tier cold --max-objects 1000 --max-duration-seconds 30

Validation probe crash recovery status

Tier Add, Edit, and Verify currently validate a destination with a unique rustfs-tier-probe-<uuid> object and perform bounded compensation while the process remains alive. The rustfs-tier-probe-intent-v1 decoder, canonical durable namespace, conditional storage primitives, state machine, and crate-level inspection type are present only as a dormant foundation. No validation path writes this record, no startup or periodic recovery scans it, and no admin HTTP route exposes it. V1 requires the owner to remain exactly equal to the immutable creator; takeover would require a new schema with explicit proof. Both durable writing and destructive recovery remain disabled until the fleet capability, operation-generation revalidation, provider timeout, retention, and operator contracts are approved.

Do not search the internal metadata bucket for these records as evidence that validation is crash recoverable: a current server does not create them. If a process is killed after the remote probe PUT but before cleanup, inspect the destination provider manually and retain ambiguous candidates. Never delete an empty or guessed version, and do not hand-create a probe intent to authorize cleanup.

Inspect the aggregate counters before widening scope. Full object-key lists are intentionally not returned. If RUSTFS_RPC_SECRET or other credentials were pasted into an issue, chat, log, or ticket while debugging tiering, rotate them on every node, restart the cluster with the new value, and redact the exposed copy before sharing more diagnostics.

Reconcile an unknown transition upload

Historical transition transactions in upload_outcome_unknown state can use an explicit two-stage operator workflow when the tier probe is ambiguous and the provider supports exact version deletion. The endpoint refuses transactions that are still inside their ownership window or are in any other state.

1. Inspect the transaction without changing it:

   GET /rustfs/admin/v3/ilm/transition/reconcile/<transaction-id>
   

2. If independent provider evidence identifies the exact remote version to remove, submit that opaque version identifier with explicit confirmation. This performs only an exact version delete; the response reports whether the transaction journal was still observed afterwards, since background recovery may have finalized the same transaction concurrently:

   POST /rustfs/admin/v3/ilm/transition/reconcile/<transaction-id>
   {
     "action": "delete_candidate",
     "confirm": true,
     "remote_version_id": "<exact-provider-version>"
   }
   

3. If the journal remains, inspect again and finalize only after the live provider probe proves the candidate is missing:

   POST /rustfs/admin/v3/ilm/transition/reconcile/<transaction-id>
   {
     "action": "finalize_missing",
     "confirm": true
   }
   

finalize_missing re-runs the provider probe and fails closed for unversioned_present, versioned_present, ambiguous, unsupported, or probe errors. It never accepts an operator assertion in place of a live missing result. Providers without an authoritative probe or exact version deletion remain pending; the endpoint does not infer provider capabilities, accept external absence assertions, or select a candidate automatically.

Reconcile legacy transition-version metadata

This section describes an approved target that is not implemented yet. The current server has no admin route that backfills a missing transitioned-version-state in xl.meta. Do not use the transaction reconcile route above for this purpose: that route owns an upload transaction candidate and may delete it, while legacy metadata reconciliation is non-destructive and may update only the exact local metadata version.

The approved interface is synchronous and accepts exactly one bucket/object/local-version tuple:

GET  /rustfs/admin/v3/ilm/transition/state/reconcile?bucket=<bucket>&object=<object>&versionId=<local-version-id>
POST /rustfs/admin/v3/ilm/transition/state/reconcile?bucket=<bucket>&object=<object>&versionId=<local-version-id>

versionId is required; use the literal null for a locally unversioned object. An omitted or empty selector is invalid. GET requires admin:ListTier. It reports the authoritative all-pool tuple, destination identity, fleet/topology readiness, live probe classification, opaque expected-tuple digest, and a machine-readable diagnosis. It returns ready-to-migrate, not migrated, when a missing state is provable because GET is read-only.

POST requires admin:SetTier, confirm: true, and the complete immutable source tuple, original per-set missing-state representations, proposed target, and reconciliation digest returned by GET. The server rereads every authoritative copy and repeats the bounded live backend probe; provider console output or an operator-supplied state is diagnostic evidence only, never write authority. A retry accepts only copies that still match their digest-bound original representation or already equal the exact proven target; any other divergence is stale or corrupt. The server may persist only one of these exact state/version pairs, together with the bound destination identity:

Proven remote model	State	Version value
Versioning disabled	KnownDisabled	Empty/absent; later requests omit versionId
Versioning suspended null object	SuspendedNull	Literal null
One exact version	Exact	Exact nonempty, non-null opaque identifier

The response outcome is migrated, retained-ambiguous, corrupt, or backend-unavailable. migrated means strong all-pool readback proved the same state and destination identity on every authoritative copy; it can be idempotent with changed=false. Ambiguous/missing/multiple probe results are retained, and explicit Unknown, malformed or conflicting dual keys, nil identifiers, partial tuples, or copies outside the exact {original missing representation, proven target} retry subset fail closed. An unavailable backend, tier generation, metadata quorum, or required strong readback reports backend-unavailable; a monotonic partial write is retained for retry and never rolled back.

The POST does not issue remote DELETE or PUT, remove local data, create a free-version, clean a transaction/journal, or change tier configuration. It holds the approved fleet/topology, bucket-lifecycle, exact tier-generation/destination, and stable all-pool object-version fences across authoritative reread and the bounded probe; it rechecks them before quorum writes and after strong readback. A fleet containing a node that cannot preserve the explicit state/destination binding is inspect-only, and a cross-pool first match is never enough.

There is intentionally no bucket, prefix, or fleet selector. Batch repair requires a separate durable, resumable job protocol and remains future work. Until the single-record route is implemented, retain affected metadata, use external inspection only for diagnosis, and never hand-edit xl.meta or enable remote cleanup by assuming that an empty version field means an unversioned tier.

The full approved fence, quorum, cross-set retry, destination-binding, and mixed-version contract is specified in ../architecture/ilm-tiering-persistence-contracts.md.

Invariant: local-first expiry ordering

expire_transitioned_object deletes local metadata first (making the object unreachable) and leaves a persisted free-version for remote-tier cleanup. tier_free_version_recovery.rs scans and re-enqueues that record; the lifecycle worker's cleanup_free_version_exact in bucket_lifecycle_ops.rs performs the fenced remote delete, local-marker cleanup, and rescan. Never remove a remote tier version while live local metadata still points at it: doing so lets a concurrent GET read a stored version_id whose remote version is already gone and fail with NoSuchVersion.

Regression test: serial_tests::test_expire_transitioned_object_never_races_concurrent_get in crates/scanner/tests/lifecycle_integration_test.rs (CI ILM Integration serial lane) pins both the local-first ordering and the "concurrent GET never sees NoSuchVersion" contract.