fix(admin): expose per-target disableProxy through remote target admin API

The read-proxy selector already honors a target's disable_proxy flag
(PR #6172), but the admin API still rejected the field, so the only way
to set it was importing a MinIO-written bucket-targets.json.

- move disableProxy from REMOTE_TARGET_UNSUPPORTED_FIELDS to
  REMOTE_TARGET_WRITABLE_FIELDS (set-remote-target create accepts it)
- add TargetUpdateOp::Proxy so set-remote-target?update=true&proxy=true
  overlays only the proxy group (MinIO TargetUpdateType parity)
- bump REMOTE_TARGET_CAPABILITY_CONTRACT_VERSION 1 -> 2 and update the
  runtime capability pin tests
- keep edge/edgeSyncBeforeExpiry rejected (no implementation behind them)
- pin that a published TargetClient carries disable_proxy, the field the
  proxy-target selector consults

Refs rustfs/backlog#1950

Cargo.lock

@@ -3843,6 +3843,7 @@ dependencies = [
  "s3s",
  "serde",
  "serde_json",
+ "serial_test",
  "sha2 0.11.0",
  "suppaftp",
  "time",
@@ -9803,6 +9804,7 @@ dependencies = [
  "rustfs-replication",
  "rustfs-storage-api",
  "s3s",
+ "serial_test",
  "temp-env",
  "time",
  "tokio",
@@ -9918,6 +9920,7 @@ dependencies = [
  "rustfs-config",
  "rustfs-io-metrics",
  "rustfs-utils",
+ "serial_test",
  "temp-env",
  "tempfile",
  "tokio",
@@ -10290,6 +10293,7 @@ dependencies = [
  "s3s",
  "serde",
  "serde_json",
+ "serial_test",
  "sha2 0.11.0",
  "temp-env",
  "tempfile",

crates/e2e_test/Cargo.toml

@@ -96,6 +96,7 @@ tokio-stream = { workspace = true }
 rustfs-madmin.workspace = true
 rustfs-filemeta.workspace = true
 bytes = { workspace = true, features = ["serde"] }
+serial_test = { workspace = true }
 aws-sdk-s3 = { workspace = true, default-features = false, features = ["sigv4a", "default-https-client", "rt-tokio"] }
 aws-sdk-sts = { workspace = true, default-features = false, features = ["default-https-client", "rt-tokio"] }
 aws-config = { workspace = true }

crates/e2e_test/src/degraded_read_eof_regression_test.rs

@@ -55,6 +55,7 @@ mod tests {
     use aws_sdk_s3::Client;
     use aws_sdk_s3::primitives::ByteStream;
     use aws_sdk_s3::types::{CompletedMultipartUpload, CompletedPart};
+    use serial_test::serial;
     use sha2::{Digest, Sha256};
     use std::error::Error;
     use tokio::time::{Duration, timeout};
@@ -268,6 +269,7 @@ mod tests {
     /// stripes) and a multipart object (3 parts × 5 MiB) must GET back as a
     /// full, byte-identical body with the correct Content-Length. No early EOF.
     #[tokio::test]
+    #[serial]
     async fn degraded_read_large_objects_with_one_disk_offline_return_full_body() -> TestResult {
         init_logging();
         info!("dist-13 (a): large-object degraded read with one of four disks offline");
@@ -333,6 +335,7 @@ mod tests {
     /// mid-stream — the exact window the fixes had to reconstruct through rather
     /// than truncate.
     #[tokio::test]
+    #[serial]
     async fn degraded_read_reconstructs_through_midstream_bitrot_within_quorum() -> TestResult {
         init_logging();
         info!("dist-13 (b): mid-stream bitrot within quorum must reconstruct a full body");
@@ -390,6 +393,7 @@ mod tests {
     /// Content-Length. `get_checked` panics on that forbidden outcome, so this
     /// test fails loudly if the truncation bug ever returns.
     #[tokio::test]
+    #[serial]
     async fn beyond_quorum_degraded_read_never_silently_truncates() -> TestResult {
         init_logging();
         info!("dist-13 (c): beyond-quorum degraded read must fail, never 200+truncated");

crates/e2e_test/src/get_stream_failure_observability_test.rs

@@ -51,6 +51,7 @@ mod tests {
     use aws_sdk_s3::Client;
     use aws_sdk_s3::primitives::ByteStream;
     use aws_sdk_s3::types::{CompletedMultipartUpload, CompletedPart};
+    use serial_test::serial;
     use std::error::Error;
     use tokio::time::{Duration, timeout};
     use tracing::info;
@@ -128,6 +129,7 @@ mod tests {
     /// the body — and assert the server log names the object, at the log level a
     /// default deployment actually runs with.
     #[tokio::test]
+    #[serial]
     async fn midstream_get_failure_is_logged_with_the_object_at_default_log_level() -> TestResult {
         init_logging();
         info!("rustfs#4784: a mid-stream GET failure must name its object in the source log");

crates/e2e_test/src/inline_fast_path_cluster_test.rs

@@ -46,6 +46,7 @@ use prost::Message;
 use rustfs_signer::constants::UNSIGNED_PAYLOAD;
 use rustfs_signer::sign_v4;
 use s3s::Body;
+use serial_test::serial;
 use std::collections::BTreeMap;
 use std::convert::Infallible;
 use std::error::Error;
@@ -1694,6 +1695,7 @@ fn assert_storage_layout(
 }
 
 #[tokio::test]
+#[serial]
 async fn four_node_inline_storage_and_get_boundaries() -> TestResult {
     init_logging();
 
@@ -1765,6 +1767,7 @@ async fn four_node_inline_storage_and_get_boundaries() -> TestResult {
 }
 
 #[tokio::test]
+#[serial]
 async fn four_node_empty_legacy_volumes_start_as_fresh() -> TestResult {
     init_logging();
 
@@ -1802,6 +1805,7 @@ async fn four_node_empty_legacy_volumes_start_as_fresh() -> TestResult {
 }
 
 #[tokio::test]
+#[serial]
 async fn four_node_inline_fallback_controls() -> TestResult {
     init_logging();
 
@@ -1866,6 +1870,7 @@ async fn four_node_inline_fallback_controls() -> TestResult {
 }
 
 #[tokio::test]
+#[serial]
 async fn four_node_compressed_inline_fallback() -> TestResult {
     init_logging();
 
@@ -1900,6 +1905,7 @@ async fn four_node_compressed_inline_fallback() -> TestResult {
 /// Multipart disk compression is live again, so a compression-enabled cluster classifies multipart objects as compressed and the roundtrip (full GET plus partNumber GET) must still return the original bytes.
 /// Reverting the multipart compression fix must fail this test.
 #[tokio::test]
+#[serial]
 async fn four_node_multipart_disk_compression_roundtrip() -> TestResult {
     init_logging();
 
@@ -1946,6 +1952,7 @@ async fn four_node_multipart_disk_compression_roundtrip() -> TestResult {
 /// read costs on the order of the covering part's block size against a ~5 MiB
 /// object.
 #[tokio::test]
+#[serial]
 async fn four_node_compressed_multipart_tail_range_reads_are_bounded() -> TestResult {
     init_logging();
 
@@ -2012,6 +2019,7 @@ async fn four_node_compressed_multipart_tail_range_reads_are_bounded() -> TestRe
 }
 
 #[tokio::test]
+#[serial]
 async fn four_node_mixed_msgpack_compat_mode_preserves_fallback_controls() -> TestResult {
     init_logging();
 
@@ -2115,6 +2123,7 @@ async fn four_node_mixed_msgpack_compat_mode_preserves_fallback_controls() -> Te
 }
 
 #[tokio::test]
+#[serial]
 async fn four_node_add_tier_converges() -> TestResult {
     init_logging();
 
@@ -2133,6 +2142,7 @@ async fn four_node_add_tier_converges() -> TestResult {
 }
 
 #[tokio::test]
+#[serial]
 async fn four_node_add_tier_converges_after_offline_node_restart_without_second_mutation() -> TestResult {
     init_logging();
 
@@ -2154,6 +2164,7 @@ async fn four_node_add_tier_converges_after_offline_node_restart_without_second_
 }
 
 #[tokio::test]
+#[serial]
 async fn four_node_manual_transition_job_status_survives_node_restart() -> TestResult {
     init_logging();
 
@@ -2228,6 +2239,7 @@ async fn four_node_manual_transition_job_status_survives_node_restart() -> TestR
 }
 
 #[tokio::test]
+#[serial]
 async fn four_node_manual_transition_distributed_admission_conflict_reports_status_and_backpressure() -> TestResult {
     init_logging();
 
@@ -2369,6 +2381,7 @@ async fn four_node_manual_transition_distributed_admission_conflict_reports_stat
 }
 
 #[tokio::test]
+#[serial]
 #[ignore = "manual #1508 evidence harness: starts a 4-node cluster, a remote tier, and an in-flight transition job"]
 async fn four_node_manual_transition_rollout_non_empty_restart_readback() -> TestResult {
     init_logging();
@@ -2473,6 +2486,7 @@ async fn four_node_manual_transition_rollout_non_empty_restart_readback() -> Tes
 }
 
 #[tokio::test]
+#[serial]
 async fn four_node_mixed_msgpack_compat_mode_preserves_fallback_controls_during_transition() -> TestResult {
     init_logging();
 
@@ -2584,6 +2598,7 @@ async fn four_node_mixed_msgpack_compat_mode_preserves_fallback_controls_during_
 }
 
 #[tokio::test]
+#[serial]
 async fn four_node_transitioned_inline_fallback() -> TestResult {
     init_logging();
 

crates/e2e_test/src/kms/kms_vault_test.rs

@@ -19,6 +19,7 @@
 //! multipart upload behaviour.
 
 use crate::common::{TEST_BUCKET, init_logging};
+use serial_test::serial;
 use tokio::time::{Duration, sleep};
 use tracing::{error, info};
 
@@ -61,6 +62,7 @@ impl VaultKmsTestContext {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_vault_kms_end_to_end() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     init_logging();
     if skip_if_kms_admin_tool_unavailable("test_vault_kms_end_to_end") {
@@ -116,6 +118,7 @@ async fn test_vault_kms_end_to_end() -> Result<(), Box<dyn std::error::Error + S
 }
 
 #[tokio::test]
+#[serial]
 async fn test_vault_kms_key_isolation() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     init_logging();
     if skip_if_kms_admin_tool_unavailable("test_vault_kms_key_isolation") {
@@ -202,6 +205,7 @@ async fn test_vault_kms_key_isolation() -> Result<(), Box<dyn std::error::Error
 }
 
 #[tokio::test]
+#[serial]
 async fn test_vault_kms_large_file() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     init_logging();
     if skip_if_kms_admin_tool_unavailable("test_vault_kms_large_file") {
@@ -266,6 +270,7 @@ async fn test_vault_kms_large_file() -> Result<(), Box<dyn std::error::Error + S
 }
 
 #[tokio::test]
+#[serial]
 async fn test_vault_kms_multipart_upload() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     init_logging();
     if skip_if_kms_admin_tool_unavailable("test_vault_kms_multipart_upload") {
@@ -296,6 +301,7 @@ async fn test_vault_kms_multipart_upload() -> Result<(), Box<dyn std::error::Err
 }
 
 #[tokio::test]
+#[serial]
 async fn test_vault_kms_key_operations() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     init_logging();
     if skip_if_kms_admin_tool_unavailable("test_vault_kms_key_operations") {

crates/e2e_test/src/policy/policy_variables_test.rs

@@ -17,6 +17,7 @@
 use crate::common::{awscurl_delete, awscurl_put, init_logging};
 use crate::policy::test_env::PolicyTestEnvironment;
 use aws_sdk_s3::primitives::ByteStream;
+use serial_test::serial;
 use tracing::info;
 
 /// Helper function to create a regular user with given credentials
@@ -121,6 +122,7 @@ async fn cleanup_user_and_policy(env: &PolicyTestEnvironment, username: &str, po
 
 /// Test AWS policy variables with single-value scenarios
 #[tokio::test(flavor = "multi_thread")]
+#[serial]
 #[ignore = "Starts a rustfs server; enable when running full E2E"]
 pub async fn test_aws_policy_variables_single_value() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     test_aws_policy_variables_single_value_impl().await
@@ -273,6 +275,7 @@ pub async fn test_aws_policy_variables_single_value_impl_with_env(
 
 /// Test AWS policy variables with multi-value scenarios
 #[tokio::test(flavor = "multi_thread")]
+#[serial]
 #[ignore = "Starts a rustfs server; enable when running full E2E"]
 pub async fn test_aws_policy_variables_multi_value() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     test_aws_policy_variables_multi_value_impl().await
@@ -398,6 +401,7 @@ pub async fn test_aws_policy_variables_multi_value_impl_with_env(
 
 /// Test AWS policy variables with variable concatenation
 #[tokio::test(flavor = "multi_thread")]
+#[serial]
 #[ignore = "Starts a rustfs server; enable when running full E2E"]
 pub async fn test_aws_policy_variables_concatenation() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     test_aws_policy_variables_concatenation_impl().await
@@ -487,6 +491,7 @@ pub async fn test_aws_policy_variables_concatenation_impl_with_env(
 
 /// Test AWS policy variables with nested scenarios
 #[tokio::test(flavor = "multi_thread")]
+#[serial]
 #[ignore = "Starts a rustfs server; enable when running full E2E"]
 pub async fn test_aws_policy_variables_nested() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     test_aws_policy_variables_nested_impl().await
@@ -504,6 +509,7 @@ pub async fn test_aws_policy_variables_nested_impl() -> Result<(), Box<dyn std::
 
 /// Test AWS policy variables with STS temporary credentials
 #[tokio::test(flavor = "multi_thread")]
+#[serial]
 #[ignore = "Starts a rustfs server; enable when running full E2E"]
 pub async fn test_aws_policy_variables_sts() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     test_aws_policy_variables_sts_impl().await
@@ -699,6 +705,7 @@ pub async fn test_aws_policy_variables_sts_impl_with_env(
 
 /// Test AWS policy variables with deny scenarios
 #[tokio::test(flavor = "multi_thread")]
+#[serial]
 #[ignore = "Starts a rustfs server; enable when running full E2E"]
 pub async fn test_aws_policy_variables_deny() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     test_aws_policy_variables_deny_impl().await

crates/e2e_test/src/policy/test_runner.rs

@@ -14,6 +14,7 @@
 
 use crate::common::init_logging;
 use crate::policy::test_env::PolicyTestEnvironment;
+use serial_test::serial;
 use std::time::Instant;
 use tokio::time::{Duration, sleep};
 use tracing::{error, info};
@@ -212,6 +213,7 @@ impl PolicyTestSuite {
 
 /// Test suite
 #[tokio::test]
+#[serial]
 #[ignore = "Connects to existing rustfs server"]
 async fn test_policy_critical_suite() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     let config = TestSuiteConfig {

crates/e2e_test/src/protocols/webdav_core.rs

@@ -41,6 +41,7 @@ use reqwest::Client;
 use rustfs_signer::constants::UNSIGNED_PAYLOAD;
 use rustfs_signer::sign_v4;
 use s3s::Body;
+use serial_test::serial;
 use tokio::process::Command;
 use tracing::info;
 
@@ -820,6 +821,7 @@ pub async fn test_webdav_core_operations() -> Result<()> {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_webdav_core_operations_direct() -> Result<()> {
     test_webdav_core_operations().await
 }

crates/e2e_test/src/reliability_disk_fault_test.rs

@@ -27,6 +27,7 @@ mod tests {
     use aws_sdk_s3::Client;
     use aws_sdk_s3::primitives::ByteStream;
     use aws_sdk_s3::types::{BucketVersioningStatus, CompletedMultipartUpload, CompletedPart, VersioningConfiguration};
+    use serial_test::serial;
     use sha2::{Digest, Sha256};
     use std::collections::HashSet;
     use std::error::Error;
@@ -156,6 +157,7 @@ mod tests {
     /// content, degraded writes must succeed, and everything must still
     /// verify after the disk returns.
     #[tokio::test]
+    #[serial]
     async fn test_degraded_read_write_with_one_disk_offline() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
         init_logging();
         info!("Reliability: degraded read/write with one of four disks offline");
@@ -208,6 +210,7 @@ mod tests {
     /// bytes to a reader: per-shard bitrot checksums reject the bad shard and
     /// the object is reconstructed from the remaining shards.
     #[tokio::test]
+    #[serial]
     async fn test_bitrot_corrupted_shard_read_returns_correct_data() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
         init_logging();
         info!("Reliability: GET must read through a bitrot-corrupted shard");
@@ -250,6 +253,7 @@ mod tests {
     /// heal, and require the replaced disk to be rebuilt and all content to
     /// verify against the sha256 manifest.
     #[tokio::test]
+    #[serial]
     async fn test_fresh_disk_replacement_heals_after_sigkill_restart() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
         init_logging();
         info!("Reliability: fresh-disk replacement heals after SIGKILL restart");
@@ -323,6 +327,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_versioned_shard_census_selects_each_version_data_dir() -> Result<(), Box<dyn Error + Send + Sync>> {
         init_logging();
         info!("Reliability: physical shard census selects the requested object version");

crates/e2e_test/src/replacement_privileged_e2e_test.rs

@@ -29,6 +29,7 @@ mod tests {
     use aws_sdk_s3::primitives::ByteStream;
     use aws_sdk_s3::types::{BucketVersioningStatus, CompletedMultipartUpload, CompletedPart, VersioningConfiguration};
     use http::Method;
+    use serial_test::serial;
     use sha2::{Digest, Sha256};
     use std::collections::BTreeSet;
     use std::error::Error;
@@ -1060,6 +1061,7 @@ mod tests {
     /// Linux mount namespaces are per-thread; keep mount setup and process
     /// spawning on one OS thread so child RustFS nodes inherit the test mounts.
     #[tokio::test(flavor = "current_thread")]
+    #[serial]
     #[ignore = "requires Linux root/CAP_SYS_ADMIN and RUSTFS_PRIVILEGED_REPLACEMENT_E2E=1"]
     async fn test_privileged_3x4_auto_replacement_rebuilds_ec8_plus_4_without_admin_heal()
     -> Result<(), Box<dyn Error + Send + Sync>> {
@@ -1073,6 +1075,7 @@ mod tests {
     /// Linux mount namespaces are per-thread; keep mount setup and process
     /// spawning on one OS thread so child RustFS nodes inherit the test mounts.
     #[tokio::test(flavor = "current_thread")]
+    #[serial]
     #[ignore = "requires Linux root/CAP_SYS_ADMIN and RUSTFS_PRIVILEGED_REPLACEMENT_E2E=1"]
     async fn test_privileged_3x4_auto_replacement_rebuilds_ec6_plus_6_without_admin_heal()
     -> Result<(), Box<dyn Error + Send + Sync>> {

crates/ecstore/src/bucket/bucket_target_sys.rs

@@ -3425,6 +3425,44 @@ mod tests {
         assert!(mutexes.contains_key("second"));
     }
 
+    #[tokio::test]
+    async fn update_all_targets_publishes_disable_proxy_on_target_client() {
+        // The read-proxy selector (replication_proxy::get_proxy_targets) skips
+        // targets whose TargetClient carries disable_proxy — the persisted
+        // per-target opt-out must survive client publication.
+        let sys = BucketTargetSys::default();
+        let target = |arn: &str, disable_proxy: bool| BucketTarget {
+            arn: arn.to_string(),
+            endpoint: "192.168.1.10:9000".to_string(),
+            target_bucket: "target-bucket".to_string(),
+            region: "us-east-1".to_string(),
+            disable_proxy,
+            credentials: Some(Credentials {
+                access_key: "access".to_string(),
+                secret_key: "secret".to_string(),
+                session_token: None,
+                expiration: None,
+            }),
+            ..Default::default()
+        };
+        let targets = BucketTargets {
+            targets: vec![target("arn:proxied", false), target("arn:opted-out", true)],
+        };
+
+        sys.update_all_targets("bucket", Some(&targets)).await;
+
+        let proxied = sys
+            .get_remote_target_client("bucket", "arn:proxied")
+            .await
+            .expect("client should be published");
+        assert!(!proxied.disable_proxy);
+        let opted_out = sys
+            .get_remote_target_client("bucket", "arn:opted-out")
+            .await
+            .expect("client should be published");
+        assert!(opted_out.disable_proxy, "disable_proxy must reach the published TargetClient");
+    }
+
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
     async fn target_updates_serialize_client_build_through_publication_per_bucket() {
         let sys = Arc::new(BucketTargetSys::default());

crates/lifecycle/Cargo.toml

@@ -69,7 +69,7 @@ uuid = { workspace = true, features = ["v4", "serde", "fast-rng", "macro-diagnos
 [dev-dependencies]
 metrics-util = { workspace = true, features = ["debugging"] }
 proptest = "1"
-serial_test = { workspace = true }
+serial_test.workspace = true
 temp-env.workspace = true
 tokio = { workspace = true, features = ["macros", "fs", "rt-multi-thread"] }
 

crates/lifecycle/src/core.rs

@@ -1564,6 +1564,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn abort_incomplete_multipart_upload_due_accepts_zero_days() {
         let initiated = OffsetDateTime::from_unix_timestamp(1_000_000).unwrap();
         let lc = BucketLifecycleConfiguration {
@@ -1624,6 +1625,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn predict_expiration_selects_closest_expiry_for_put_object() {
         let base_time = OffsetDateTime::from_unix_timestamp(1_000_000).unwrap();
         let lc = BucketLifecycleConfiguration {
@@ -1870,6 +1872,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn empty_transition_vectors_are_not_active_or_due() {
         let lc = BucketLifecycleConfiguration {
             expiry_updated_at: None,
@@ -1935,6 +1938,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn eval_inner_keeps_latest_object_before_days_due() {
         let base_time = OffsetDateTime::from_unix_timestamp(1_000_000).unwrap();
         let lc = BucketLifecycleConfiguration {
@@ -1968,6 +1972,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn eval_inner_transitions_latest_object_after_days_due() {
         let base_time = OffsetDateTime::from_unix_timestamp(1_000_000).unwrap();
         let lc = BucketLifecycleConfiguration {
@@ -2005,6 +2010,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn eval_inner_transitions_latest_object_after_date_due() {
         let base_time = OffsetDateTime::from_unix_timestamp(1_000_000).unwrap();
         let transition_date = base_time - Duration::days(1);
@@ -2044,6 +2050,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn eval_inner_selects_earliest_due_among_multiple_past_due_events() {
         let base_time = OffsetDateTime::from_unix_timestamp(1_000_000).unwrap();
         // Two enabled rules both yield a past-due DeleteAction and a third yields a
@@ -2157,6 +2164,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn eval_inner_expires_noncurrent_version_after_due() {
         let base_time = OffsetDateTime::from_unix_timestamp(1_000_000).unwrap();
         let lc = BucketLifecycleConfiguration {
@@ -2194,6 +2202,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn eval_inner_skips_noncurrent_expiration_without_successor() {
         let base_time = OffsetDateTime::from_unix_timestamp(1_000_000).expect("valid fixed test timestamp");
         let lc = BucketLifecycleConfiguration {
@@ -2229,6 +2238,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn eval_inner_missing_successor_does_not_skip_noncurrent_transition() {
         let base_time = OffsetDateTime::from_unix_timestamp(1_000_000).expect("valid fixed test timestamp");
         let lc = BucketLifecycleConfiguration {
@@ -2271,6 +2281,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn eval_inner_noncurrent_expiration_one_day_respects_due_boundary() {
         let successor_time = datetime!(2025-06-15 12:00:00 UTC);
         let due = expected_expiry_time(successor_time, 1);
@@ -2312,6 +2323,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn eval_inner_expires_noncurrent_version_immediately_when_zero_days() {
         let base_time = OffsetDateTime::from_unix_timestamp(1_000_000).unwrap();
         let lc = BucketLifecycleConfiguration {
@@ -2349,6 +2361,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn eval_inner_transitions_noncurrent_version_after_due() {
         let base_time = OffsetDateTime::from_unix_timestamp(1_000_000).unwrap();
         let lc = BucketLifecycleConfiguration {
@@ -2424,6 +2437,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn evaluator_honors_newer_noncurrent_versions_retention_count() {
         let base_time = OffsetDateTime::from_unix_timestamp(1_000_000).unwrap();
         let lc = Arc::new(BucketLifecycleConfiguration {
@@ -2712,6 +2726,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn expired_object_delete_marker_ignores_marker_with_noncurrent_versions_present() {
         let base_time = OffsetDateTime::from_unix_timestamp(1_000_000).unwrap();
         let lc = BucketLifecycleConfiguration {
@@ -2788,6 +2803,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn expired_object_delete_marker_deletes_only_delete_marker_immediately() {
         let base_time = OffsetDateTime::from_unix_timestamp(1_000_000).unwrap();
         let lc = BucketLifecycleConfiguration {
@@ -2865,6 +2881,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn expiration_days_deletes_only_expired_delete_marker_when_due() {
         let base_time = OffsetDateTime::from_unix_timestamp(1_000_000).unwrap();
         let lc = BucketLifecycleConfiguration {
@@ -2915,6 +2932,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn expiration_days_uses_earliest_due_rule_for_expired_delete_marker() {
         let base_time = OffsetDateTime::from_unix_timestamp(1_000_000).unwrap();
         let make_rule = |id: &str, days| LifecycleRule {
@@ -3245,6 +3263,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn del_marker_expiration_deletes_marker_and_older_versions_when_due() {
         let base_time = OffsetDateTime::from_unix_timestamp(1_000_000).expect("fixed timestamp should be valid");
         let lc = BucketLifecycleConfiguration {
@@ -3284,6 +3303,7 @@ mod tests {
     // --- TASK-003 tests: Round up to next UTC processing boundary ---
 
     #[test]
+    #[serial]
     fn expected_expiry_time_rounds_up_to_next_midnight_utc() {
         with_default_ilm_process_time(|| {
             // Object created at 2025-01-15T10:30:45Z, expire in 30 days
@@ -3299,6 +3319,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn expected_expiry_time_immediate_expiry_returns_epoch() {
         with_default_ilm_process_time(|| {
             let mod_time = datetime!(2025-06-01 12:00:00 UTC);
@@ -3308,6 +3329,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn expected_expiry_time_preserves_exact_midnight_boundary() {
         with_default_ilm_process_time(|| {
             let mod_time = datetime!(2025-03-01 00:00:00 UTC);
@@ -3317,6 +3339,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn expected_expiry_time_rounds_end_of_day_to_following_midnight() {
         with_default_ilm_process_time(|| {
             let mod_time = datetime!(2025-06-15 23:59:59 UTC);
@@ -3326,6 +3349,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn expected_expiry_time_uses_canonical_process_time_boundary() {
         let mod_time = datetime!(2025-01-15 10:30:45 UTC);
 
@@ -3338,6 +3362,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn expected_expiry_time_uses_deprecated_process_time_alias() {
         let mod_time = datetime!(2025-01-15 10:30:45 UTC);
 
@@ -3350,6 +3375,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn expected_expiry_time_uses_default_boundary_when_process_time_is_zero_or_invalid() {
         let mod_time = datetime!(2025-01-15 10:30:45 UTC);
 
@@ -3372,6 +3398,7 @@ mod tests {
 
     // (a) Default path (env unset) is byte-identical: one day == 86400s.
     #[test]
+    #[serial]
     fn ilm_day_secs_defaults_to_86400_when_unset() {
         temp_env::with_var_unset(ENV_ILM_DEBUG_DAY_SECS, || {
             assert_eq!(ilm_day_secs(), DEFAULT_ILM_DAY_SECS);
@@ -3400,6 +3427,7 @@ mod tests {
 
     // (b) End-to-end env read scales the day length.
     #[test]
+    #[serial]
     fn ilm_day_secs_scales_when_env_set() {
         temp_env::with_var(ENV_ILM_DEBUG_DAY_SECS, Some("2"), || {
             assert_eq!(ilm_day_secs(), 2);
@@ -3408,6 +3436,7 @@ mod tests {
 
     // (c) Invalid env value falls back to 86400.
     #[test]
+    #[serial]
     fn ilm_day_secs_falls_back_on_invalid_env() {
         temp_env::with_var(ENV_ILM_DEBUG_DAY_SECS, Some("bogus"), || {
             assert_eq!(ilm_day_secs(), DEFAULT_ILM_DAY_SECS);
@@ -3420,6 +3449,7 @@ mod tests {
     // Deadline math scales: with a 1s day and PROCESS_TIME unset, a Days=1 rule is
     // due 1s after mod_time (rounded up to the next 1s boundary => same instant).
     #[test]
+    #[serial]
     fn expected_expiry_time_scales_with_debug_day_secs() {
         let mod_time = datetime!(2025-01-15 10:30:45 UTC);
         temp_env::with_var(ENV_ILM_DEBUG_DAY_SECS, Some("1"), || {
@@ -3435,6 +3465,7 @@ mod tests {
 
     // days == 0 still yields the immediate-expiry sentinel regardless of the switch.
     #[test]
+    #[serial]
     fn expected_expiry_time_zero_days_ignores_debug_day_secs() {
         let mod_time = datetime!(2025-06-01 12:00:00 UTC);
         temp_env::with_var(ENV_ILM_DEBUG_DAY_SECS, Some("2"), || {
@@ -3445,6 +3476,7 @@ mod tests {
     // (③) Interaction with an explicit RUSTFS_ILM_PROCESS_TIME: the deadline offset
     // uses the accelerated day length, but the rounding boundary honors PROCESS_TIME.
     #[test]
+    #[serial]
     fn expected_expiry_time_debug_day_secs_respects_explicit_process_time() {
         let mod_time = datetime!(2025-01-15 10:30:00 UTC);
         // day == 10s, but round up to the next 60s (PROCESS_TIME) boundary.
@@ -3461,6 +3493,7 @@ mod tests {
 
     // (③) With the switch unset, an explicit PROCESS_TIME behaves exactly as before.
     #[test]
+    #[serial]
     fn expected_expiry_time_unset_debug_day_secs_matches_legacy_process_time() {
         let mod_time = datetime!(2025-01-15 10:30:45 UTC);
         temp_env::with_var_unset(ENV_ILM_DEBUG_DAY_SECS, || {
@@ -3488,6 +3521,7 @@ mod tests {
 
     // The abort-incomplete-multipart deadline path also scales through the switch.
     #[test]
+    #[serial]
     fn abort_incomplete_multipart_due_scales_with_debug_day_secs() {
         use s3s::dto::AbortIncompleteMultipartUpload;
         let initiated = datetime!(2025-01-15 10:30:45 UTC);
@@ -3532,6 +3566,7 @@ mod tests {
     // (⑤ evaluator seam) A Days=1 rule fires under RUSTFS_ILM_DEBUG_DAY_SECS=1 once
     // `now` advances a few seconds past a mod_time only ~seconds in the past.
     #[test]
+    #[serial]
     fn eval_inner_expires_days_one_rule_under_debug_day_secs() {
         let lc = BucketLifecycleConfiguration {
             expiry_updated_at: None,
@@ -3580,6 +3615,7 @@ mod tests {
 
     // Absolute Date-based rules must NOT scale with the switch (regression guard).
     #[test]
+    #[serial]
     fn eval_inner_date_rule_ignores_debug_day_secs() {
         let expiry_date = datetime!(2025-06-01 00:00:00 UTC);
         let lc = BucketLifecycleConfiguration {
@@ -3837,6 +3873,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn eval_inner_triggers_delete_all_versions_when_expired_object_all_versions_set() {
         let base_time = OffsetDateTime::from_unix_timestamp(1_000_000).unwrap();
         let lc = BucketLifecycleConfiguration {
@@ -3875,6 +3912,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn expired_object_all_versions_does_not_apply_to_current_delete_marker() {
         let base_time = OffsetDateTime::from_unix_timestamp(1_000_000).expect("fixed timestamp should be valid");
         let lc = BucketLifecycleConfiguration {
@@ -3904,6 +3942,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn eval_inner_uses_delete_action_when_all_versions_not_set() {
         let base_time = OffsetDateTime::from_unix_timestamp(1_000_000).unwrap();
         let lc = BucketLifecycleConfiguration {
@@ -4022,6 +4061,7 @@ mod tests {
         use super::*;
         use proptest::prelude::*;
         use s3s::dto::{NoncurrentVersionExpiration, Tag};
+        use serial_test::serial;
 
         const DAY_SECS: i64 = 86400;
 
@@ -4252,6 +4292,7 @@ mod tests {
             /// combination, and must be deterministic: the same input
             /// evaluated twice yields an identical event.
             #[test]
+            #[serial]
             fn eval_inner_never_panics_and_is_deterministic(
                 rules in prop::collection::vec(arb_rule(), 0..4),
                 obj in arb_object_opts(),
@@ -4391,6 +4432,7 @@ mod tests {
             /// candidate set — earliest due wins, ties prefer delete-class —
             /// and must be `NoneAction` exactly when that set is empty.
             #[test]
+            #[serial]
             fn eval_inner_winner_matches_selection_oracle(
                 rules in prop::collection::vec(arb_selection_rule(), 0..5),
                 mod_off in 0i64..(2 * DAY_SECS),
@@ -4444,6 +4486,7 @@ mod tests {
             /// non-decreasing in `days` (days == 0 maps to UNIX_EPOCH, below
             /// any post-1970 deadline).
             #[test]
+            #[serial]
             fn expected_expiry_time_is_monotonic_in_days(
                 mod_off in 0i64..(3650 * DAY_SECS),
                 d1 in 0i32..2000,
@@ -4465,6 +4508,7 @@ mod tests {
             /// to the next whole-day boundary: the result is day-aligned, not
             /// before `mod_time + days`, and less than one boundary beyond it.
             #[test]
+            #[serial]
             fn expected_expiry_time_lands_on_default_day_boundary(
                 mod_off in 0i64..(3650 * DAY_SECS),
                 days in 1i32..2000,
@@ -4482,6 +4526,7 @@ mod tests {
             /// to that boundary instead: aligned to it, never early, and less
             /// than one boundary late.
             #[test]
+            #[serial]
             fn expected_expiry_time_lands_on_explicit_process_boundary(
                 mod_off in 0i64..(365 * DAY_SECS),
                 days in 1i32..400,

crates/object-capacity/Cargo.toml

@@ -73,6 +73,7 @@ walkdir = { workspace = true }
 
 [dev-dependencies]
 criterion = { workspace = true, features = ["html_reports"] }
+serial_test = { workspace = true }
 temp-env = { workspace = true, features = ["async_closure"] }
 tempfile = { workspace = true }
 tokio = { workspace = true, features = ["test-util", "macros", "fs", "rt-multi-thread"] }

crates/object-capacity/src/capacity_manager.rs

@@ -1484,6 +1484,7 @@ mod tests {
         ENV_CAPACITY_SAMPLE_RATE, ENV_CAPACITY_STAT_TIMEOUT, ENV_CAPACITY_WRITE_FREQUENCY_THRESHOLD,
         ENV_CAPACITY_WRITE_TRIGGER_DELAY,
     };
+    use serial_test::serial;
     use std::sync::Arc;
     use std::sync::atomic::{AtomicUsize, Ordering};
 
@@ -1668,6 +1669,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn test_config_getter_defaults() {
         for (env_var, getter, default, _, _) in config_getter_cases() {
             temp_env::with_var(env_var, None::<&str>, || {
@@ -1677,6 +1679,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn test_config_getter_env_overrides() {
         for (env_var, getter, _, override_value, expected) in config_getter_cases() {
             temp_env::with_var(env_var, Some(override_value), || {
@@ -1686,6 +1689,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn test_zero_env_values_clamp_to_defaults() {
         // A zero threshold makes small disks report 0 bytes; a zero timeout
         // (with dynamic timeout off) makes every scan fail. Both must fall
@@ -1705,6 +1709,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_update_capacity_preserves_retrieval_metadata() {
         let manager = HybridCapacityManager::from_env();
 
@@ -1720,6 +1725,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_record_write_operation() {
         let manager = HybridCapacityManager::from_env();
 
@@ -1730,6 +1736,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_write_frequency_window() {
         let manager = HybridCapacityManager::from_env();
 
@@ -1817,6 +1824,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn test_recent_write_count_ignores_future_buckets() {
         let record = WriteRecord::new();
         record.write_buckets[0].store(120, 3);
@@ -1830,6 +1838,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_needs_fast_update() {
         let manager = HybridCapacityManager::from_env();
 
@@ -1846,6 +1855,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_cache_age_tracking() {
         let manager = HybridCapacityManager::from_env();
 
@@ -1865,6 +1875,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_data_source_tracking() {
         let manager = HybridCapacityManager::from_env();
 
@@ -1880,6 +1891,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_needs_fast_update_waits_for_write_trigger_delay() {
         let manager = create_isolated_manager(HybridStrategyConfig {
             scheduled_update_interval: Duration::from_secs(60),
@@ -1910,6 +1922,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_needs_fast_update_respects_enable_write_trigger() {
         let manager = create_isolated_manager(HybridStrategyConfig {
             scheduled_update_interval: Duration::from_secs(60),
@@ -1936,6 +1949,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_concurrent_access() {
         let manager = Arc::new(HybridCapacityManager::from_env());
         let mut handles = Vec::new();
@@ -1962,6 +1976,7 @@ mod tests {
     // exact under heavy same-second contention or the frequency window (and the
     // write-trigger decision) would undercount.
     #[tokio::test(flavor = "multi_thread", worker_threads = 8)]
+    #[serial]
     async fn test_record_write_operation_lock_free_is_exact_under_contention() {
         let manager = Arc::new(HybridCapacityManager::from_env());
         let mut handles = Vec::new();
@@ -1986,6 +2001,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_performance_overhead() {
         let manager = Arc::new(HybridCapacityManager::from_env());
         let start = Instant::now();
@@ -2002,6 +2018,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_refresh_or_join_singleflight() {
         let manager = Arc::new(HybridCapacityManager::from_env());
         let calls = Arc::new(AtomicUsize::new(0));
@@ -2041,6 +2058,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_refresh_or_join_recovers_after_leader_cancellation() {
         let manager = Arc::new(HybridCapacityManager::from_env());
 
@@ -2069,6 +2087,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_refresh_or_join_cancelled_leader_unblocks_joiner() {
         let manager = Arc::new(HybridCapacityManager::from_env());
 
@@ -2096,6 +2115,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_spawn_refresh_if_needed_deduplicates_background_refresh() {
         let manager = Arc::new(HybridCapacityManager::from_env());
         let calls = Arc::new(AtomicUsize::new(0));
@@ -2133,6 +2153,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_record_write_operation_with_scope_token_marks_dirty_disks() {
         let manager = create_isolated_manager(HybridStrategyConfig::default());
         let token = uuid::Uuid::new_v4();
@@ -2156,6 +2177,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_get_dirty_disks_drains_global_dirty_scope_registry() {
         let manager = create_isolated_manager(HybridStrategyConfig::default());
         record_global_dirty_scope(CapacityScope {
@@ -2175,6 +2197,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_update_capacity_recomputes_total_from_disk_cache_for_subset_refresh() {
         let manager = create_isolated_manager(HybridStrategyConfig::default());
 
@@ -2285,6 +2308,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_update_capacity_degraded_full_refresh_merges_cache_and_does_not_oscillate() {
         let manager = create_isolated_manager(HybridStrategyConfig::default());
 
@@ -2330,6 +2354,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_update_capacity_degraded_with_empty_per_disk_serves_merged_cache() {
         let manager = create_isolated_manager(HybridStrategyConfig::default());
         manager.update_capacity(full_two_disk_update(), DataSource::RealTime).await;
@@ -2359,6 +2384,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_update_capacity_degraded_without_complete_cache_keeps_partial_sum() {
         let manager = create_isolated_manager(HybridStrategyConfig::default());
 
@@ -2399,6 +2425,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_commit_keeps_dirty_marks_recorded_after_scan_start() {
         let manager = create_isolated_manager(HybridStrategyConfig::default());
         let disk = scope_disk("node-a", "/tmp/disk-a");
@@ -2429,6 +2456,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_commit_clears_dirty_marks_recorded_before_scan_start() {
         let manager = create_isolated_manager(HybridStrategyConfig::default());
         let disk = scope_disk("node-a", "/tmp/disk-a");
@@ -2449,6 +2477,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_retain_dirty_disks_within_drops_ghost_entries() {
         let manager = create_isolated_manager(HybridStrategyConfig::default());
         let local = scope_disk("node-a", "/tmp/disk-a");
@@ -2467,6 +2496,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_spawn_refresh_recovers_from_construction_panic() {
         let manager = create_isolated_manager(HybridStrategyConfig::default());
 
@@ -2533,6 +2563,7 @@ mod tests {
     }
 
     #[tokio::test(start_paused = true)]
+    #[serial]
     async fn test_refresh_or_join_joiner_times_out_when_leader_wedges() {
         let manager = create_isolated_manager(HybridStrategyConfig::default());
 
@@ -2560,6 +2591,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_refresh_or_join_returns_cluster_total_for_dirty_subset() {
         let manager = create_isolated_manager(HybridStrategyConfig::default());
 
@@ -2641,6 +2673,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_config_from_env() {
         let config = HybridStrategyConfig::from_env();
 
@@ -2654,6 +2687,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_config_from_env_with_override() {
         temp_env::with_var(ENV_CAPACITY_SCHEDULED_INTERVAL, Some("600"), || {
             let config = HybridStrategyConfig::from_env();

crates/object-capacity/src/scan.rs

@@ -1069,6 +1069,7 @@ mod tests {
     #[cfg(unix)]
     use rustfs_config::ENV_CAPACITY_FOLLOW_SYMLINKS;
     use rustfs_config::{ENV_CAPACITY_MAX_FILES_THRESHOLD, ENV_CAPACITY_SAMPLE_RATE};
+    use serial_test::serial;
 
     /// Reference implementation using unbounded `u128` arithmetic, clamped to
     /// `u64::MAX`, used as the source of truth for the sampling extrapolation.
@@ -1273,6 +1274,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_get_dir_size_async_nonexistent_directory() {
         let result = get_dir_size_async(Path::new("/nonexistent/path")).await;
         assert!(result.is_err());
@@ -1646,6 +1648,7 @@ mod tests {
     }
 
     #[tokio::test]
+    #[serial]
     async fn test_metadata_incomplete_aggregate_does_not_replace_disk_cache() {
         use std::fs::File;
         use std::io::Write;
@@ -1780,6 +1783,7 @@ mod tests {
 
     #[cfg(unix)]
     #[tokio::test]
+    #[serial]
     async fn test_get_dir_size_async_ignores_symlink_targets_when_follow_disabled() {
         use std::fs::File;
         use std::io::Write;
@@ -1805,6 +1809,7 @@ mod tests {
 
     #[cfg(unix)]
     #[tokio::test]
+    #[serial]
     async fn test_get_dir_size_async_counts_symlink_targets_when_follow_enabled() {
         use std::fs::File;
         use std::io::Write;

crates/obs/src/metrics/collectors/bucket_replication.rs

@@ -75,7 +75,7 @@ pub struct BucketReplicationBandwidthStats {
 }
 
 #[derive(Debug, Clone, Default)]
-pub struct BucketReplicationMetricsSnapshot {
+pub struct BucketReplicationStats {
     pub bucket: String,
     pub total_failed_bytes: u64,
     pub total_failed_count: u64,
@@ -107,7 +107,7 @@ pub struct BucketReplicationMetricsSnapshot {
 
 #[derive(Debug, Clone, Default)]
 pub(crate) struct BucketReplicationRuntimeStats {
-    pub(crate) stats: BucketReplicationMetricsSnapshot,
+    pub(crate) stats: BucketReplicationStats,
     pub(crate) target_flows: Vec<BucketReplicationTargetFlowStats>,
 }
 
@@ -182,7 +182,7 @@ fn push_proxy_request_result_metrics(
     }
 }
 
-pub fn collect_bucket_replication_metrics(stats: &[BucketReplicationMetricsSnapshot]) -> Vec<PrometheusMetric> {
+pub fn collect_bucket_replication_metrics(stats: &[BucketReplicationStats]) -> Vec<PrometheusMetric> {
     if stats.is_empty() {
         return Vec::new();
     }
@@ -572,7 +572,7 @@ mod tests {
     #[test]
     fn test_collect_bucket_replication_metrics() {
         let stats = vec![BucketReplicationRuntimeStats {
-            stats: BucketReplicationMetricsSnapshot {
+            stats: BucketReplicationStats {
                 bucket: "b1".to_string(),
                 total_failed_bytes: 64,
                 total_failed_count: 2,
@@ -876,7 +876,7 @@ mod tests {
 
     #[test]
     fn test_collect_bucket_replication_metrics_empty() {
-        let stats: Vec<BucketReplicationMetricsSnapshot> = Vec::new();
+        let stats: Vec<BucketReplicationStats> = Vec::new();
         let metrics = collect_bucket_replication_metrics(&stats);
         assert!(metrics.is_empty());
     }

crates/obs/src/metrics/collectors/mod.rs

@@ -48,7 +48,7 @@ pub(crate) use bucket_replication::{
     BucketReplicationTargetFlowStats, collect_bucket_replication_backlog_metrics, collect_bucket_replication_runtime_metrics,
 };
 pub use bucket_replication::{
-    BucketReplicationBandwidthStats, BucketReplicationMetricsSnapshot, BucketReplicationTargetStats,
+    BucketReplicationBandwidthStats, BucketReplicationStats, BucketReplicationTargetStats,
     collect_bucket_replication_bandwidth_metrics, collect_bucket_replication_metrics,
 };
 pub use cluster::{ClusterStats, collect_cluster_metrics};
@@ -68,8 +68,8 @@ pub(crate) use notification::collect_notification_runtime_metrics;
 pub use notification::{NotificationStats, collect_notification_metrics};
 pub(crate) use notification_target::{NotificationTargetRuntimeStats, collect_notification_target_runtime_metrics};
 pub use notification_target::{NotificationTargetStats, collect_notification_target_metrics};
-pub use replication::{ReplicationMetricsSnapshot, collect_replication_metrics};
 pub(crate) use replication::{ReplicationRuntimeStats, collect_replication_runtime_metrics};
+pub use replication::{ReplicationStats, collect_replication_metrics};
 pub(crate) use request::{ApiRequestMetricSupport, ApiRequestStats, collect_request_metrics};
 pub use resource::{ResourceStats, collect_resource_metrics};
 pub(crate) use scanner::{ScannerRuntimeStats, collect_scanner_runtime_metrics};

crates/obs/src/metrics/collectors/replication.rs

@@ -22,7 +22,7 @@ use crate::metrics::schema::replication::*;
 
 /// Replication statistics.
 #[derive(Debug, Clone, Default)]
-pub struct ReplicationMetricsSnapshot {
+pub struct ReplicationStats {
     /// Average number of active replication workers
     pub average_active_workers: f64,
     /// Average queued bytes since server start
@@ -54,13 +54,13 @@ pub struct ReplicationMetricsSnapshot {
 #[derive(Debug, Clone, Default)]
 pub(crate) struct ReplicationRuntimeStats {
     pub(crate) server: String,
-    pub(crate) stats: ReplicationMetricsSnapshot,
+    pub(crate) stats: ReplicationStats,
 }
 
 /// Collects replication metrics from the given stats.
 ///
 /// Returns a vector of Prometheus metrics for replication statistics.
-pub fn collect_replication_metrics(stats: &ReplicationMetricsSnapshot) -> Vec<PrometheusMetric> {
+pub fn collect_replication_metrics(stats: &ReplicationStats) -> Vec<PrometheusMetric> {
     vec![
         PrometheusMetric::from_descriptor(&REPLICATION_AVERAGE_ACTIVE_WORKERS_MD, stats.average_active_workers),
         PrometheusMetric::from_descriptor(&REPLICATION_AVERAGE_QUEUED_BYTES_MD, stats.average_queued_bytes as f64),
@@ -120,7 +120,7 @@ mod tests {
 
     #[test]
     fn test_collect_replication_metrics() {
-        let stats = ReplicationMetricsSnapshot {
+        let stats = ReplicationStats {
             average_active_workers: 8.5,
             average_queued_bytes: 1024 * 1024 * 40,
             average_queued_count: 240,
@@ -182,7 +182,7 @@ mod tests {
 
     #[test]
     fn test_collect_replication_metrics_default() {
-        let stats = ReplicationMetricsSnapshot::default();
+        let stats = ReplicationStats::default();
         let metrics = collect_replication_metrics(&stats);
 
         assert_eq!(metrics.len(), 13);
@@ -194,7 +194,7 @@ mod tests {
 
     #[test]
     fn replication_stats_struct_literal_keeps_legacy_fields() {
-        let stats = ReplicationMetricsSnapshot {
+        let stats = ReplicationStats {
             average_active_workers: 1.0,
             average_queued_bytes: 2,
             average_queued_count: 3,

crates/obs/src/metrics/scheduler.rs

@@ -2811,14 +2811,14 @@ mod tests {
     #[test]
     fn replication_proxy_bucket_keys_detect_removed_buckets() {
         let previous = repl_proxy_bucket_live_keys(&[BucketReplicationRuntimeStats {
-            stats: crate::metrics::BucketReplicationMetricsSnapshot {
+            stats: crate::metrics::BucketReplicationStats {
                 bucket: "photos".to_string(),
                 ..Default::default()
             },
             ..Default::default()
         }]);
         let current = repl_proxy_bucket_live_keys(&[BucketReplicationRuntimeStats {
-            stats: crate::metrics::BucketReplicationMetricsSnapshot {
+            stats: crate::metrics::BucketReplicationStats {
                 bucket: "logs".to_string(),
                 ..Default::default()
             },

crates/obs/src/metrics/stats_collector.rs

@@ -21,12 +21,12 @@
 use crate::metrics::collectors::scanner::{ScannerActiveBucketDriveStats, ScannerBucketDriveResultStats, ScannerSourceWorkStats};
 use crate::metrics::collectors::{
     ApiRequestMetricSupport, ApiRequestStats, BucketReplicationBacklogStats, BucketReplicationBandwidthStats,
-    BucketReplicationMetricsSnapshot, BucketReplicationRuntimeStats, BucketReplicationTargetBacklogStats,
-    BucketReplicationTargetFlowStats, BucketReplicationTargetStats, BucketStats, BucketUsageStats, ClusterConfigStats,
-    ClusterHealthStats, ClusterStats, ClusterUsageStats, CompressionClusterStats, CpuStats, DiskStats, DriveCountStats,
-    DriveDetailedStats, DriveRuntimeDetailedStats, ErasureSetStats, HostNetworkStats, IamStats, IlmActionTaskStats,
-    IlmBackpressureStats, IlmQueueTaskStats, IlmRuntimeStats, IlmStats, IlmTaskEventStats, MemoryStats, NetworkStats,
-    ProcessStats, ProcessStatusType, ReplicationMetricsSnapshot, ResourceStats, ScannerRuntimeStats, ScannerStats,
+    BucketReplicationRuntimeStats, BucketReplicationStats, BucketReplicationTargetBacklogStats, BucketReplicationTargetFlowStats,
+    BucketReplicationTargetStats, BucketStats, BucketUsageStats, ClusterConfigStats, ClusterHealthStats, ClusterStats,
+    ClusterUsageStats, CompressionClusterStats, CpuStats, DiskStats, DriveCountStats, DriveDetailedStats,
+    DriveRuntimeDetailedStats, ErasureSetStats, HostNetworkStats, IamStats, IlmActionTaskStats, IlmBackpressureStats,
+    IlmQueueTaskStats, IlmRuntimeStats, IlmStats, IlmTaskEventStats, MemoryStats, NetworkStats, ProcessStats, ProcessStatusType,
+    ReplicationStats, ResourceStats, ScannerRuntimeStats, ScannerStats,
 };
 use crate::metrics::runtime_sources::{ObsIlmRuntimeSnapshot, bucket_monitor_handle, iam_metrics_snapshot, ilm_runtime_snapshot};
 use crate::metrics::{
@@ -266,7 +266,7 @@ fn bucket_replication_detail_from_snapshot(stats: ObsBucketReplicationStatsSnaps
 
     BucketReplicationRuntimeStats {
         target_flows,
-        stats: BucketReplicationMetricsSnapshot {
+        stats: BucketReplicationStats {
             bucket,
             total_failed_bytes: stats.total_failed_bytes,
             total_failed_count: stats.total_failed_count,
@@ -298,7 +298,7 @@ fn bucket_replication_detail_from_snapshot(stats: ObsBucketReplicationStatsSnaps
     }
 }
 
-async fn obs_site_replication_stats() -> ReplicationMetricsSnapshot {
+async fn obs_site_replication_stats() -> ReplicationStats {
     let current_data_transfer_rate = obs_bucket_replication_bandwidth_stats()
         .into_iter()
         .flatten()
@@ -306,7 +306,7 @@ async fn obs_site_replication_stats() -> ReplicationMetricsSnapshot {
         .sum::<f64>();
     let stats = obs_replication_site_stats_snapshot(current_data_transfer_rate).await;
 
-    ReplicationMetricsSnapshot {
+    ReplicationStats {
         average_active_workers: stats.average_active_workers,
         average_queued_bytes: stats.average_queued_bytes,
         average_queued_count: stats.average_queued_count,
@@ -648,7 +648,7 @@ pub fn collect_bucket_replication_bandwidth_stats() -> Vec<BucketReplicationBand
 }
 
 /// Collect bucket and target level replication stats from the global replication runtime.
-pub async fn collect_bucket_replication_detail_stats() -> Vec<BucketReplicationMetricsSnapshot> {
+pub async fn collect_bucket_replication_detail_stats() -> Vec<BucketReplicationStats> {
     obs_bucket_replication_stats_snapshot()
         .await
         .into_iter()
@@ -662,7 +662,7 @@ pub(crate) async fn collect_bucket_replication_stats_bundle()
 }
 
 /// Collect site-level replication stats from the global replication runtime.
-pub async fn collect_replication_stats() -> ReplicationMetricsSnapshot {
+pub async fn collect_replication_stats() -> ReplicationStats {
     obs_site_replication_stats().await
 }
 

crates/replication/src/config.rs

@@ -60,7 +60,9 @@ pub const REPLICATION_READ_ONLY_HISTORICAL_FIELDS: &[&str] = &[
     "Destination.ReplicationTime",
 ];
 
-pub const REMOTE_TARGET_CAPABILITY_CONTRACT_VERSION: u32 = 1;
+// v2: disableProxy moved from unsupported to writable (per-target read-proxy
+// opt-out is accepted by set-remote-target and the `proxy` update op).
+pub const REMOTE_TARGET_CAPABILITY_CONTRACT_VERSION: u32 = 2;
 
 pub const REMOTE_TARGET_WRITABLE_FIELDS: &[&str] = &[
     "sourcebucket",
@@ -83,9 +85,12 @@ pub const REMOTE_TARGET_WRITABLE_FIELDS: &[&str] = &[
     // madmin default of 60s); the per-target health-check interval is not
     // yet applied — the heartbeat keeps its global env-configured interval.
     "healthCheckDuration",
+    // Per-target read-proxy opt-out, consumed by the proxy-target selector
+    // (contract v2; previously only importable via MinIO bucket-targets.json).
+    "disableProxy",
 ];
 
-pub const REMOTE_TARGET_UNSUPPORTED_FIELDS: &[&str] = &["disableProxy", "edge", "edgeSyncBeforeExpiry"];
+pub const REMOTE_TARGET_UNSUPPORTED_FIELDS: &[&str] = &["edge", "edgeSyncBeforeExpiry"];
 
 #[derive(Debug, Clone, Serialize, Deserialize, Default)]
 pub struct ObjectOpts {

crates/scanner/Cargo.toml

@@ -103,7 +103,8 @@ hex-simd.workspace = true
 
 [dev-dependencies]
 tracing-subscriber = { workspace = true, features = ["json", "env-filter", "time"] }
-temp-env = { workspace = true, features = ["async_closure"] }
+serial_test = { workspace = true }
+temp-env = { workspace = true }
 tempfile = { workspace = true }
 uuid = { workspace = true, features = ["v4", "serde", "fast-rng", "macro-diagnostics"] }
 tokio = { workspace = true, features = ["test-util", "fs", "rt-multi-thread"] }

crates/scanner/src/lib.rs

@@ -599,8 +599,10 @@ impl ScannerConfigObjectDelete for ECStore {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use serial_test::serial;
 
     #[tokio::test]
+    #[serial]
     async fn runtime_tier_names_serves_cached_arc_within_ttl() {
         reset_tier_name_cache_for_test();
         // The tier config manager is unconfigured in unit tests, so the
@@ -614,6 +616,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn foreground_read_guard_tracks_stream_lifetime() {
         reset_foreground_read_activity_for_test();
         assert_eq!(current_foreground_read_activity(), 0);
@@ -627,6 +630,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn foreground_read_activity_keeps_larger_signal() {
         reset_foreground_read_activity_for_test();
         let _guard = ForegroundReadGuard::new();
@@ -639,6 +643,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn scanner_runtime_guard_tracks_runtime_lifetime() {
         reset_scanner_runtime_instances_for_test();
         assert!(!scanner_runtime_initialized());

crates/scanner/src/runtime_config.rs

@@ -868,6 +868,7 @@ mod tests {
         SCANNER_CYCLE_MAX_DIRECTORIES, SCANNER_CYCLE_MAX_DURATION, SCANNER_CYCLE_MAX_OBJECTS, SCANNER_DELAY, SCANNER_IDLE_MODE,
         SCANNER_SPEED, SCANNER_SUB_SYS, ScannerSpeed,
     };
+    use serial_test::serial;
     use std::collections::HashMap;
     use std::time::Duration;
     use temp_env::{with_var, with_var_unset};
@@ -915,6 +916,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn scanner_runtime_config_uses_persisted_values_when_env_is_unset() {
         let config = server_config_with_scanner(&[
             (SCANNER_SPEED, "slow"),
@@ -942,6 +944,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn scanner_runtime_config_normalizes_persisted_default_speed() {
         let config = server_config_with_scanner(&[(SCANNER_SPEED, "default")]);
 
@@ -957,6 +960,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn scanner_runtime_config_prefers_env_over_persisted_config() {
         let config = server_config_with_scanner(&[(SCANNER_SPEED, "slowest"), (SCANNER_CYCLE, "600")]);
 
@@ -973,6 +977,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn scanner_runtime_config_prefers_heal_bitrot_cycle_over_scanner_compat_config() {
         let config = server_config_with_scanner_and_heal(&[(SCANNER_BITROT_CYCLE, "3600")], &[(HEAL_BITROT_CYCLE, "off")]);
 
@@ -985,6 +990,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn scanner_runtime_config_marks_scanner_bitrot_cycle_as_compat_source() {
         let config = server_config_with_scanner(&[(SCANNER_BITROT_CYCLE, "3600")]);
 
@@ -1001,6 +1007,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn scanner_runtime_config_normalizes_persisted_default_bitrot_cycles() {
         let default_cycle = DEFAULT_HEAL_BITROT_CYCLE_SECS.to_string();
         for config in [
@@ -1025,6 +1032,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn scanner_runtime_config_validation_rejects_invalid_persisted_speed_with_env_override() {
         let config = server_config_with_scanner(&[(SCANNER_SPEED, "warp")]);
 
@@ -1058,6 +1066,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn scanner_runtime_config_uses_derived_delay_for_excessive_env_override() {
         let config = server_config_with_scanner(&[(SCANNER_SPEED, "slow")]);
 
@@ -1078,6 +1087,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn scanner_runtime_config_status_reports_value_sources() {
         let config = server_config_with_scanner(&[(SCANNER_CYCLE_MAX_OBJECTS, "100"), (SCANNER_CACHE_SAVE_TIMEOUT, "5")]);
 
@@ -1098,6 +1108,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn applied_runtime_config_is_the_authoritative_scheduler_state() {
         let config = server_config_with_scanner(&[(SCANNER_CYCLE, "321")]);
 
@@ -1114,6 +1125,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn scanner_runtime_config_status_reports_persisted_pacing_overrides() {
         let config = server_config_with_scanner(&[("delay", "3.5"), ("max_wait", "7")]);
 
@@ -1135,6 +1147,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn scanner_runtime_config_status_prefers_env_pacing_overrides() {
         let config = server_config_with_scanner(&[("delay", "3.5"), ("max_wait", "7")]);
 
@@ -1156,6 +1169,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn scanner_runtime_config_status_preserves_subsecond_max_wait() {
         let config = server_config_with_scanner(&[(SCANNER_SPEED, "fast")]);
 

crates/scanner/src/scanner/tests.rs

@@ -19,6 +19,7 @@ use crate::{
     ScannerObjectInfo as ObjectInfo, ScannerObjectOptions as ObjectOptions, ScannerPutObjReader as PutObjReader,
     init_bucket_metadata_sys_for_scanner_tests, init_ecstore_config_for_scanner_tests, init_local_disks_with_instance_ctx,
 };
+use serial_test::serial;
 use std::collections::HashMap;
 use std::io::Cursor;
 use std::task::Poll;
@@ -361,6 +362,7 @@ fn test_initial_scanner_delay_uses_configured_start_delay() {
 }
 
 #[test]
+#[serial]
 fn test_initial_scanner_delay_uses_cycle_without_explicit_start_delay() {
     with_var(ENV_SCANNER_CYCLE, Some("120"), || {
         crate::runtime_config::refresh_scanner_runtime_config_for_tests();
@@ -407,6 +409,7 @@ fn test_initial_scanner_delay_keeps_delay_for_replication_without_buckets() {
 }
 
 #[test]
+#[serial]
 fn test_scanner_cycle_max_duration_uses_env() {
     with_var(ENV_SCANNER_CYCLE_MAX_DURATION_SECS, Some("42"), || {
         assert_eq!(scanner_cycle_max_duration(), Some(Duration::from_secs(42)));
@@ -414,6 +417,7 @@ fn test_scanner_cycle_max_duration_uses_env() {
 }
 
 #[test]
+#[serial]
 fn test_scanner_cycle_max_duration_default_is_disabled() {
     with_var_unset(ENV_SCANNER_CYCLE_MAX_DURATION_SECS, || {
         assert_eq!(scanner_cycle_max_duration(), None);
@@ -457,6 +461,7 @@ async fn test_scanner_cycle_budget_drop_cancels_child_without_elapsed() {
 }
 
 #[test]
+#[serial]
 fn test_scanner_cycle_budget_config_uses_work_budget_env() {
     with_var(ENV_SCANNER_CYCLE_MAX_OBJECTS, Some("100"), || {
         with_var(ENV_SCANNER_CYCLE_MAX_DIRECTORIES, Some("25"), || {
@@ -468,6 +473,7 @@ fn test_scanner_cycle_budget_config_uses_work_budget_env() {
 }
 
 #[test]
+#[serial]
 fn test_scanner_cycle_budget_config_disables_zero_work_budgets() {
     with_var(ENV_SCANNER_CYCLE_MAX_OBJECTS, Some("0"), || {
         with_var(ENV_SCANNER_CYCLE_MAX_DIRECTORIES, Some("0"), || {
@@ -510,6 +516,7 @@ fn test_scan_cycle_partial_source_maps_budget_reason() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_mark_scan_cycle_idle_clears_published_cycle_state() {
     let mut cycle_info = CurrentCycle {
         current: 12,
@@ -538,6 +545,7 @@ async fn test_mark_scan_cycle_idle_clears_published_cycle_state() {
 }
 
 #[tokio::test]
+#[serial]
 async fn scanner_cycle_metrics_guard_covers_published_first_cycle_lifetime() {
     let cycle_started = Utc::now() - chrono::Duration::seconds(5);
     let mut cycle_info = CurrentCycle {
@@ -564,6 +572,7 @@ async fn scanner_cycle_metrics_guard_covers_published_first_cycle_lifetime() {
 }
 
 #[tokio::test]
+#[serial]
 async fn scanner_cycle_metrics_guard_keeps_active_cycle_published_during_finalization() {
     let mut cycle_info = CurrentCycle {
         current: 12,
@@ -588,6 +597,7 @@ async fn scanner_cycle_metrics_guard_keeps_active_cycle_published_during_finaliz
 }
 
 #[tokio::test]
+#[serial]
 async fn scanner_cycle_metrics_guard_drop_clears_activity() {
     let guard = ScannerCycleMetricsGuard::new(CurrentCycle {
         current: 12,
@@ -605,6 +615,7 @@ async fn scanner_cycle_metrics_guard_drop_clears_activity() {
 }
 
 #[tokio::test]
+#[serial]
 async fn run_data_scanner_cycle_publishes_activity_for_owner_lifetime() {
     let (_temp_dir, store) = setup_scanner_cycle_store().await;
     let ctx = CancellationToken::new();
@@ -655,6 +666,7 @@ async fn run_data_scanner_cycle_publishes_activity_for_owner_lifetime() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_finalize_partial_scan_cycle_advances_and_persists_counter() {
     let store = Arc::new(MemoryConfigStore::default());
     let ctx = CancellationToken::new();
@@ -690,6 +702,7 @@ async fn test_finalize_partial_scan_cycle_advances_and_persists_counter() {
 }
 
 #[tokio::test]
+#[serial]
 async fn scanner_cycle_recovers_to_newer_durable_cache_floor() {
     let store = Arc::new(MemoryConfigStore::default());
     let ctx = CancellationToken::new();
@@ -729,6 +742,7 @@ async fn scanner_cycle_recovers_to_newer_durable_cache_floor() {
 }
 
 #[tokio::test]
+#[serial]
 async fn scanner_cycle_rejects_invalid_cache_floor() {
     let store = Arc::new(MemoryConfigStore::default());
     let ctx = CancellationToken::new();
@@ -999,6 +1013,7 @@ async fn scanner_usage_floor_fails_closed_on_corrupt_or_exhausted_usage_state()
 }
 
 #[tokio::test]
+#[serial]
 async fn scanner_usage_backup_uses_durable_cycle_cadence_across_tasks() {
     let store = Arc::new(MemoryConfigStore::default());
     let ctx = CancellationToken::new();
@@ -1072,6 +1087,7 @@ fn scanner_cycle_advance_fails_before_reserved_exhausted_value() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_finalize_partial_scan_cycle_reports_persist_failure() {
     let store = Arc::new(MemoryConfigStore::default());
     let ctx = CancellationToken::new();
@@ -1095,6 +1111,7 @@ async fn test_finalize_partial_scan_cycle_reports_persist_failure() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_persist_scanner_cycle_state_reconciles_newer_winner() {
     let store = Arc::new(MemoryConfigStore::default());
     let ctx = CancellationToken::new();
@@ -1517,6 +1534,7 @@ async fn test_usage_save_route_barrier_prevents_missing_snapshot_creation() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_usage_route_barrier_precedes_durable_reconciliation() {
     let store = Arc::new(MemoryConfigStore::default());
     let key = memory_config_key(RUSTFS_META_BUCKET, DATA_USAGE_OBJ_NAME_PATH.as_str());
@@ -1544,6 +1562,7 @@ async fn test_usage_route_barrier_precedes_durable_reconciliation() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_deferred_usage_save_keeps_last_real_save_metric() {
     let metrics = global_metrics();
     metrics.record_scanner_usage_save_result(ScannerUsageSaveResult::Success);
@@ -2607,6 +2626,7 @@ fn scanner_cycle_cache_floor_stays_pending_during_deferred_usage_publication() {
 }
 
 #[test]
+#[serial]
 fn finalizing_a_saved_cycle_acknowledges_its_exact_dirty_snapshot() {
     crate::scanner_io::clear_dirty_usage_bucket("photos");
     crate::scanner_io::record_dirty_usage_bucket("photos");
@@ -2633,6 +2653,7 @@ fn finalizing_a_saved_cycle_acknowledges_its_exact_dirty_snapshot() {
 }
 
 #[test]
+#[serial]
 fn finalizing_a_deferred_usage_save_keeps_dirty_work_pending() {
     crate::scanner_io::clear_dirty_usage_bucket("photos");
     crate::scanner_io::record_dirty_usage_bucket("photos");
@@ -2675,6 +2696,7 @@ async fn scanner_cycle_keeps_remote_pending_acknowledgement() {
 }
 
 #[test]
+#[serial]
 fn finalizing_an_already_durable_cycle_acknowledges_its_exact_dirty_snapshot() {
     crate::scanner_io::clear_dirty_usage_bucket("photos");
     crate::scanner_io::record_dirty_usage_bucket("photos");
@@ -2689,6 +2711,7 @@ fn finalizing_an_already_durable_cycle_acknowledges_its_exact_dirty_snapshot() {
 }
 
 #[test]
+#[serial]
 fn finalizing_a_prior_same_cycle_snapshot_keeps_new_dirty_work_pending() {
     crate::scanner_io::clear_dirty_usage_bucket("photos");
     crate::scanner_io::record_dirty_usage_bucket("photos");
@@ -2704,6 +2727,7 @@ fn finalizing_a_prior_same_cycle_snapshot_keeps_new_dirty_work_pending() {
 }
 
 #[test]
+#[serial]
 fn finalizing_a_durable_superseded_snapshot_keeps_dirty_work_pending() {
     crate::scanner_io::clear_dirty_usage_bucket("photos");
     crate::scanner_io::record_dirty_usage_bucket("photos");
@@ -2719,6 +2743,7 @@ fn finalizing_a_durable_superseded_snapshot_keeps_dirty_work_pending() {
 }
 
 #[test]
+#[serial]
 fn data_usage_persist_wait_covers_cache_retries_and_backup() {
     with_var(rustfs_config::ENV_SCANNER_CACHE_SAVE_TIMEOUT_SECS, Some("7"), || {
         crate::runtime_config::refresh_scanner_runtime_config_for_tests();
@@ -2771,6 +2796,7 @@ async fn maintenance_feature_inspection_preserves_base_cycle_after_timeout() {
 }
 
 #[tokio::test(start_paused = true)]
+#[serial]
 async fn stable_maintenance_detection_preserves_base_cycle_after_timeout() {
     let ctx = CancellationToken::new();
 
@@ -2836,6 +2862,7 @@ async fn maintenance_feature_inspection_stops_on_cancellation() {
 }
 
 #[test]
+#[serial]
 fn test_cycle_interval_prefers_explicit_cycle_override() {
     with_var(ENV_SCANNER_SPEED, Some("slowest"), || {
         with_var(ENV_SCANNER_CYCLE, Some("42"), || {
@@ -2845,6 +2872,7 @@ fn test_cycle_interval_prefers_explicit_cycle_override() {
 }
 
 #[test]
+#[serial]
 fn test_cycle_interval_prefers_explicit_cycle_over_default_cycle() {
     let _guard = ScannerDefaultCycleGuard::set(TEST_DEFAULT_SCANNER_CYCLE_SECS);
 
@@ -2854,6 +2882,7 @@ fn test_cycle_interval_prefers_explicit_cycle_over_default_cycle() {
 }
 
 #[test]
+#[serial]
 fn test_cycle_interval_uses_scanner_default_speed_override_when_unconfigured() {
     let _guard = ScannerDefaultSpeedGuard::set(ScannerSpeed::Slowest);
 
@@ -2863,6 +2892,7 @@ fn test_cycle_interval_uses_scanner_default_speed_override_when_unconfigured() {
 }
 
 #[test]
+#[serial]
 fn test_cycle_interval_prefers_explicit_speed_over_default_speed_override() {
     let _guard = ScannerDefaultSpeedGuard::set(ScannerSpeed::Slowest);
 
@@ -2880,6 +2910,7 @@ fn test_cycle_interval_prefers_explicit_speed_over_default_speed_override() {
 }
 
 #[test]
+#[serial]
 fn test_cycle_interval_uses_default_cycle_override_when_unconfigured() {
     let _guard = ScannerDefaultCycleGuard::set(TEST_DEFAULT_SCANNER_CYCLE_SECS);
 
@@ -3043,6 +3074,7 @@ fn scanner_cycle_wait_plan_drives_growth_resets_and_bitrot_cap() {
 }
 
 #[test]
+#[serial]
 fn scanner_cycle_schedule_status_reports_effective_backoff() {
     record_scanner_cycle_schedule(Duration::from_millis(86_400_001), true, 2_048, true, 7);
 
@@ -3322,6 +3354,7 @@ fn dirty_usage_wakes_are_disabled_for_explicit_cycle_policy() {
 }
 
 #[test]
+#[serial]
 fn clean_idle_cap_preserves_default_bitrot_coverage_window() {
     let config = ScannerRuntimeConfig {
         bitrot_cycle: Some(Duration::from_secs(30 * 24 * 60 * 60)),
@@ -3351,6 +3384,7 @@ fn clean_idle_cap_allows_policy_max_when_bitrot_is_disabled() {
 }
 
 #[test]
+#[serial]
 fn clean_idle_cap_never_shortens_the_base_cycle() {
     let config = ScannerRuntimeConfig {
         bitrot_cycle: Some(Duration::from_secs(60)),
@@ -3364,6 +3398,7 @@ fn clean_idle_cap_never_shortens_the_base_cycle() {
 }
 
 #[test]
+#[serial]
 fn test_cycle_interval_keeps_default_cycle_with_explicit_speed() {
     let _guard = ScannerDefaultCycleGuard::set(TEST_DEFAULT_SCANNER_CYCLE_SECS);
 
@@ -3381,6 +3416,7 @@ fn test_cycle_interval_keeps_default_cycle_with_explicit_speed() {
 }
 
 #[test]
+#[serial]
 fn test_cycle_interval_prefers_explicit_start_delay_over_default_cycle() {
     let _guard = ScannerDefaultCycleGuard::set(TEST_DEFAULT_SCANNER_CYCLE_SECS);
 
@@ -3394,6 +3430,7 @@ fn test_cycle_interval_prefers_explicit_start_delay_over_default_cycle() {
 }
 
 #[test]
+#[serial]
 fn test_cycle_interval_supports_minio_speed_alias() {
     with_var_unset(ENV_SCANNER_SPEED, || {
         with_var_unset(ENV_SCANNER_CYCLE, || {
@@ -3407,6 +3444,7 @@ fn test_cycle_interval_supports_minio_speed_alias() {
 }
 
 #[test]
+#[serial]
 fn test_cycle_interval_supports_minio_cycle_alias() {
     with_var_unset(ENV_SCANNER_CYCLE, || {
         with_var_unset(ENV_SCANNER_START_DELAY_SECS, || {
@@ -3426,6 +3464,7 @@ fn test_randomized_cycle_delay_handles_small_start_delay() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_wait_for_next_scanner_cycle_wakes_for_dirty_usage() {
     crate::scanner_io::clear_dirty_usage_buckets_for_tests();
 
@@ -3451,6 +3490,7 @@ async fn test_wait_for_next_scanner_cycle_wakes_for_dirty_usage() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_wait_for_next_scanner_cycle_sees_unattempted_dirty_usage() {
     crate::scanner_io::clear_dirty_usage_buckets_for_tests();
     let dirty_generation = crate::scanner_io::dirty_usage_generation();
@@ -3472,6 +3512,7 @@ async fn test_wait_for_next_scanner_cycle_sees_unattempted_dirty_usage() {
 }
 
 #[tokio::test(start_paused = true)]
+#[serial]
 async fn test_wait_for_next_scanner_cycle_retries_stable_dirty_usage_on_timer() {
     crate::scanner_io::clear_dirty_usage_buckets_for_tests();
     crate::scanner_io::record_dirty_usage_bucket("photos");
@@ -3493,6 +3534,7 @@ async fn test_wait_for_next_scanner_cycle_retries_stable_dirty_usage_on_timer()
 }
 
 #[tokio::test(start_paused = true)]
+#[serial]
 async fn test_wait_for_next_scanner_cycle_can_defer_dirty_wakes_until_timer() {
     crate::scanner_io::clear_dirty_usage_buckets_for_tests();
     let ctx = CancellationToken::new();
@@ -3511,6 +3553,7 @@ async fn test_wait_for_next_scanner_cycle_can_defer_dirty_wakes_until_timer() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_wait_for_next_scanner_cycle_wakes_for_repeated_dirty_bucket() {
     crate::scanner_io::clear_dirty_usage_buckets_for_tests();
     crate::scanner_io::record_dirty_usage_bucket("photos");
@@ -3536,6 +3579,7 @@ async fn test_wait_for_next_scanner_cycle_wakes_for_repeated_dirty_bucket() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_wait_for_next_scanner_cycle_reschedules_for_runtime_config() {
     crate::scanner_io::clear_dirty_usage_buckets_for_tests();
     let observed_generation = crate::runtime_config::scanner_runtime_config_generation();
@@ -3563,6 +3607,7 @@ async fn test_wait_for_next_scanner_cycle_reschedules_for_runtime_config() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_wait_for_next_scanner_cycle_reschedules_for_maintenance_change() {
     crate::scanner_io::clear_dirty_usage_buckets_for_tests();
     let observed_generation = crate::scanner_io::scanner_maintenance_generation();
@@ -3806,6 +3851,7 @@ fn scanner_activity_after_a_cycle_restores_the_base_interval() {
 }
 
 #[tokio::test(start_paused = true)]
+#[serial]
 async fn distributed_clean_idle_wait_wakes_at_base_interval_for_remote_activity() {
     crate::scanner_io::clear_dirty_usage_buckets_for_tests();
     let ctx = CancellationToken::new();
@@ -3833,6 +3879,7 @@ async fn distributed_clean_idle_wait_wakes_at_base_interval_for_remote_activity(
 }
 
 #[tokio::test(start_paused = true)]
+#[serial]
 async fn superseded_retry_wait_defers_dirty_cluster_activity_until_timer() {
     crate::scanner_io::clear_dirty_usage_buckets_for_tests();
     let ctx = CancellationToken::new();
@@ -3860,6 +3907,7 @@ async fn superseded_retry_wait_defers_dirty_cluster_activity_until_timer() {
 }
 
 #[tokio::test(start_paused = true)]
+#[serial]
 async fn distributed_clean_idle_wait_blocks_backoff_for_unpropagated_maintenance() {
     crate::scanner_io::clear_dirty_usage_buckets_for_tests();
     let ctx = CancellationToken::new();
@@ -3886,6 +3934,7 @@ async fn distributed_clean_idle_wait_blocks_backoff_for_unpropagated_maintenance
 }
 
 #[tokio::test(start_paused = true)]
+#[serial]
 async fn distributed_clean_idle_wait_fails_closed_when_a_peer_is_unverifiable() {
     crate::scanner_io::clear_dirty_usage_buckets_for_tests();
     let ctx = CancellationToken::new();
@@ -3912,6 +3961,7 @@ async fn distributed_clean_idle_wait_fails_closed_when_a_peer_is_unverifiable()
 }
 
 #[tokio::test(start_paused = true)]
+#[serial]
 async fn distributed_clean_idle_wait_keeps_the_extended_deadline_when_peers_are_clean() {
     crate::scanner_io::clear_dirty_usage_buckets_for_tests();
     let ctx = CancellationToken::new();
@@ -3939,6 +3989,7 @@ async fn distributed_clean_idle_wait_keeps_the_extended_deadline_when_peers_are_
 }
 
 #[tokio::test(start_paused = true)]
+#[serial]
 async fn scanner_activity_probe_wait_is_cancellation_aware() {
     crate::scanner_io::clear_dirty_usage_buckets_for_tests();
     let ctx = CancellationToken::new();
@@ -3969,6 +4020,7 @@ async fn scanner_activity_probe_wait_is_cancellation_aware() {
 }
 
 #[tokio::test(start_paused = true)]
+#[serial]
 async fn scanner_activity_probe_wait_stops_after_leader_lock_loss() {
     crate::scanner_io::clear_dirty_usage_buckets_for_tests();
     let ctx = CancellationToken::new();
@@ -4000,6 +4052,7 @@ async fn scanner_activity_probe_wait_stops_after_leader_lock_loss() {
 }
 
 #[test]
+#[serial]
 fn test_get_cycle_scan_mode_runs_deep_until_selection_window_completes() {
     with_var(ENV_SCANNER_BITROT_CYCLE_SECS, Some("3600"), || {
         let mode = get_cycle_scan_mode(10, 0, Some(Utc::now()), bitrot_scan_cycle());
@@ -4008,6 +4061,7 @@ fn test_get_cycle_scan_mode_runs_deep_until_selection_window_completes() {
 }
 
 #[test]
+#[serial]
 fn test_get_cycle_scan_mode_respects_elapsed_bitrot_cycle() {
     with_var(ENV_SCANNER_BITROT_CYCLE_SECS, Some("3600"), || {
         let recent = Utc::now() - chrono::Duration::minutes(30);
@@ -4019,6 +4073,7 @@ fn test_get_cycle_scan_mode_respects_elapsed_bitrot_cycle() {
 }
 
 #[test]
+#[serial]
 fn test_get_cycle_scan_mode_can_disable_periodic_deep_scan() {
     with_var(ENV_SCANNER_BITROT_CYCLE_SECS, Some("off"), || {
         assert_eq!(get_cycle_scan_mode(1, 0, None, bitrot_scan_cycle()), HealScanMode::Normal);
@@ -4026,6 +4081,7 @@ fn test_get_cycle_scan_mode_can_disable_periodic_deep_scan() {
 }
 
 #[test]
+#[serial]
 fn test_background_heal_info_for_scan_start_marks_deep_active() {
     let now = Utc::now();
     let info =
@@ -4038,6 +4094,7 @@ fn test_background_heal_info_for_scan_start_marks_deep_active() {
 }
 
 #[test]
+#[serial]
 fn test_background_heal_info_for_scan_start_keeps_deep_window_start() {
     with_var_unset(ENV_SCANNER_BITROT_CYCLE_SECS, || {
         let started_at = Utc::now();

crates/scanner/src/scanner_folder/tests.rs

@@ -18,6 +18,7 @@ use super::*;
 use crate::storage_api::VersionPurgeStatusType;
 use crate::{DiskOption, Endpoint, STORAGE_FORMAT_FILE, TierStats, new_disk, storageclass};
 use rustfs_filemeta::{FileInfo, FileMeta};
+use serial_test::serial;
 use std::io::Write;
 #[cfg(unix)]
 use std::os::unix::fs::{PermissionsExt, symlink};
@@ -355,6 +356,7 @@ impl Drop for TestGuard {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_should_skip_failed_respects_ttl() {
     let (mut scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard::new(60, 100, &mut scanner, temp_dir);
@@ -376,6 +378,7 @@ async fn test_should_skip_failed_respects_ttl() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_record_failed_ttl_zero_noop() {
     let (mut scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard::new(0, 100, &mut scanner, temp_dir);
@@ -464,6 +467,7 @@ fn test_should_account_replication_stats_only_for_live_object_versions() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_heal_replication_only_queues_pending_null_deletes() {
     async fn replication_skipped_count() -> u64 {
         global_metrics()
@@ -712,6 +716,7 @@ async fn test_scanner_heal_admission_accounting_maps_deep_scan_to_bitrot() {
 }
 
 #[test]
+#[serial]
 fn test_excessive_version_alert_thresholds_use_env() {
     with_var(rustfs_config::ENV_SCANNER_ALERT_EXCESS_VERSIONS, Some("3"), || {
         with_var(rustfs_config::ENV_SCANNER_ALERT_EXCESS_VERSION_SIZE, Some("100"), || {
@@ -726,6 +731,7 @@ fn test_excessive_version_alert_thresholds_use_env() {
 }
 
 #[test]
+#[serial]
 fn test_excessive_folders_threshold_uses_env() {
     with_var(rustfs_config::ENV_SCANNER_ALERT_EXCESS_FOLDERS, Some("3"), || {
         crate::runtime_config::refresh_scanner_runtime_config_for_tests();
@@ -735,6 +741,7 @@ fn test_excessive_folders_threshold_uses_env() {
 }
 
 #[test]
+#[serial]
 fn test_excessive_folders_threshold_default_supports_pbs_layout() {
     with_var_unset(rustfs_config::ENV_SCANNER_ALERT_EXCESS_FOLDERS, || {
         crate::runtime_config::refresh_scanner_runtime_config_for_tests();
@@ -744,6 +751,7 @@ fn test_excessive_folders_threshold_default_supports_pbs_layout() {
 }
 
 #[test]
+#[serial]
 fn test_scanner_yield_every_n_objects_uses_env() {
     with_var(rustfs_config::ENV_SCANNER_YIELD_EVERY_N_OBJECTS, Some("32"), || {
         crate::runtime_config::refresh_scanner_runtime_config_for_tests();
@@ -753,6 +761,7 @@ fn test_scanner_yield_every_n_objects_uses_env() {
 }
 
 #[test]
+#[serial]
 fn test_scanner_yield_every_n_objects_uses_default() {
     with_var_unset(rustfs_config::ENV_SCANNER_YIELD_EVERY_N_OBJECTS, || {
         crate::runtime_config::refresh_scanner_runtime_config_for_tests();
@@ -879,6 +888,7 @@ fn test_order_folders_for_resume_reports_stale_hint() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_record_failed_prunes_to_max_entries() {
     let (mut scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard::new(1000, 2, &mut scanner, temp_dir);
@@ -910,6 +920,7 @@ async fn test_record_failed_prunes_to_max_entries() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_prune_failed_objects_cache_drops_expired() {
     let (mut scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard::new(5, 10, &mut scanner, temp_dir);
@@ -933,6 +944,7 @@ async fn test_prune_failed_objects_cache_drops_expired() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_prune_failed_objects_max_zero_keeps_fresh() {
     let (mut scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard::new(60, 0, &mut scanner, temp_dir);
@@ -1689,6 +1701,7 @@ async fn test_heal_actions_returns_actual_size_without_inline_heal() {
 }
 
 #[tokio::test]
+#[serial]
 #[cfg(unix)]
 async fn test_scan_folder_skips_unreadable_child_directory() {
     let (mut scanner, temp_dir) = build_test_scanner().await;
@@ -1721,6 +1734,7 @@ async fn test_scan_folder_skips_unreadable_child_directory() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_scan_folder_exits_when_abandoned_child_listing_finishes() {
     let (mut scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard::new(60, 100, &mut scanner, temp_dir.clone());
@@ -1799,6 +1813,7 @@ async fn test_scan_folder_exits_when_abandoned_child_listing_finishes() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_scan_folder_xl_meta_named_directory_uses_namespace_descent() {
     let (mut scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard::new(60, 100, &mut scanner, temp_dir.clone());
@@ -1844,6 +1859,7 @@ async fn test_scan_folder_xl_meta_named_directory_uses_namespace_descent() {
 }
 
 #[tokio::test(flavor = "current_thread")]
+#[serial]
 async fn test_scan_folder_corrupt_xl_meta_stops_erasure_data_dir_descent() {
     let logs = CapturedLogs::default();
     let subscriber = tracing_subscriber::fmt()
@@ -2005,6 +2021,7 @@ async fn test_scan_folder_corrupt_xl_meta_stops_erasure_data_dir_descent() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_scan_folder_missing_xl_meta_stops_erasure_data_dir_descent() {
     let (mut scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard::new(60, 100, &mut scanner, temp_dir.clone());
@@ -2082,6 +2099,7 @@ async fn test_scan_folder_missing_xl_meta_stops_erasure_data_dir_descent() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_scan_folder_uuid_namespace_part_name_directory_is_not_data_dir() {
     let (mut scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard::new(60, 100, &mut scanner, temp_dir.clone());
@@ -2143,6 +2161,7 @@ async fn test_scan_folder_uuid_namespace_part_name_directory_is_not_data_dir() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_scan_folder_non_erasure_metadata_keeps_namespace_descent() {
     let (mut scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard::new(60, 100, &mut scanner, temp_dir.clone());
@@ -2184,6 +2203,7 @@ async fn test_scan_folder_non_erasure_metadata_keeps_namespace_descent() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_scan_folder_compacted_parent_sends_partial_update() {
     let (mut scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard::new(60, 100, &mut scanner, temp_dir.clone());
@@ -2225,6 +2245,7 @@ async fn test_scan_folder_compacted_parent_sends_partial_update() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_scan_data_folder_cancelled_before_scan_clears_current_path() {
     let (scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard {
@@ -2269,6 +2290,7 @@ async fn test_scan_data_folder_cancelled_before_scan_clears_current_path() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_scan_data_folder_returns_partial_cache_on_budget_cancel() {
     let (mut scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard::new(60, 100, &mut scanner, temp_dir.clone());
@@ -2324,6 +2346,7 @@ async fn test_scan_data_folder_returns_partial_cache_on_budget_cancel() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_scan_data_folder_reports_invalid_checkpoint_ignored_once() {
     let (scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard {
@@ -2368,6 +2391,7 @@ async fn test_scan_data_folder_reports_invalid_checkpoint_ignored_once() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_scan_data_folder_resume_hint_prioritizes_next_existing_folder() {
     let (scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard {
@@ -2441,6 +2465,7 @@ async fn test_scan_data_folder_resume_hint_prioritizes_next_existing_folder() {
 }
 
 #[tokio::test]
+#[serial]
 async fn scan_data_folder_missing_bucket_returns_partial() {
     let (scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard {
@@ -2492,6 +2517,7 @@ async fn scan_data_folder_missing_bucket_returns_partial() {
 }
 
 #[tokio::test]
+#[serial]
 async fn scan_data_folder_missing_scan_root_returns_partial() {
     let (scanner, temp_dir) = build_test_scanner().await;
     tokio::fs::remove_dir_all(&temp_dir)
@@ -2537,6 +2563,7 @@ async fn scan_data_folder_missing_scan_root_returns_partial() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_scan_data_folder_resume_hint_orders_across_new_and_existing_folders() {
     let (scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard {
@@ -2605,6 +2632,7 @@ async fn test_scan_data_folder_resume_hint_orders_across_new_and_existing_folder
 }
 
 #[tokio::test]
+#[serial]
 async fn test_scan_data_folder_partial_object_budget_accumulates_progress() {
     let (scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard {
@@ -2687,6 +2715,7 @@ async fn test_scan_data_folder_partial_object_budget_accumulates_progress() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_partial_compacted_entry_does_not_carry_children() {
     let (mut scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard {
@@ -2732,6 +2761,7 @@ async fn test_partial_compacted_entry_does_not_carry_children() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_partial_entry_does_not_carry_missing_old_child() {
     let (mut scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard {
@@ -2764,6 +2794,7 @@ async fn test_partial_entry_does_not_carry_missing_old_child() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_legacy_windows_cache_rebuilds_and_round_trips_portable_keys() {
     let (scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard {
@@ -2830,6 +2861,7 @@ async fn test_legacy_windows_cache_rebuilds_and_round_trips_portable_keys() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_scan_data_folder_success_clears_resume_hint() {
     let (scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard {
@@ -2872,6 +2904,7 @@ async fn test_scan_data_folder_success_clears_resume_hint() {
 }
 
 #[tokio::test]
+#[serial]
 async fn test_scan_data_folder_keeps_unresolved_objects_partial() {
     let (scanner, temp_dir) = build_test_scanner().await;
     let _guard = TestGuard {
@@ -2918,6 +2951,7 @@ async fn test_scan_data_folder_keeps_unresolved_objects_partial() {
 }
 
 #[tokio::test]
+#[serial]
 #[cfg(unix)]
 async fn test_scan_folder_ignores_symlinked_child_directory() {
     let (mut scanner, temp_dir) = build_test_scanner().await;

crates/scanner/src/scanner_io/tests.rs

@@ -27,6 +27,7 @@ use crate::{
     init_local_disks_with_instance_ctx, new_disk, path2_bucket_object_with_base_path,
 };
 use rustfs_filemeta::FileInfo;
+use serial_test::serial;
 use temp_env::with_var;
 use time::OffsetDateTime;
 use uuid::Uuid;
@@ -102,6 +103,7 @@ async fn setup_two_pool_scanner_store() -> (tempfile::TempDir, Arc<ECStore>) {
 }
 
 #[tokio::test]
+#[serial]
 async fn scanner_cache_locks_block_same_source_workers() {
     let (_temp_dir, store) = setup_two_pool_scanner_store().await;
     let set = &store.pools[0].disk_set[0];
@@ -128,6 +130,7 @@ async fn scanner_cache_locks_block_same_source_workers() {
 }
 
 #[tokio::test]
+#[serial]
 async fn scanner_cache_locks_allow_cross_source_workers() {
     let (_temp_dir, store) = setup_two_pool_scanner_store().await;
     let first_set = &store.pools[0].disk_set[0];
@@ -146,6 +149,7 @@ async fn scanner_cache_locks_allow_cross_source_workers() {
 }
 
 #[tokio::test]
+#[serial]
 async fn scanner_cycle_is_deferred_while_rebalance_is_active() {
     let (_temp_dir, store) = setup_two_pool_scanner_store().await;
     let mut pool_stats = vec![EcstoreRebalanceStats::default(); store.pools.len()];
@@ -181,6 +185,7 @@ async fn scanner_cycle_is_deferred_while_rebalance_is_active() {
 }
 
 #[tokio::test]
+#[serial]
 async fn scanner_cycle_is_deferred_while_terminal_decommission_is_blocked() {
     let (_temp_dir, store) = setup_two_pool_scanner_store().await;
     for decommission in [
@@ -225,6 +230,7 @@ async fn data_usage_publish_fails_when_receiver_is_closed() {
 }
 
 #[tokio::test]
+#[serial]
 async fn multi_pool_scanner_cycle_publishes_combined_usage() {
     let (_temp_dir, store) = setup_two_pool_scanner_store().await;
     let bucket = format!("scanner-union-{}", Uuid::new_v4().simple());
@@ -272,6 +278,7 @@ async fn multi_pool_scanner_cycle_publishes_combined_usage() {
 }
 
 #[tokio::test]
+#[serial]
 async fn multi_pool_scanner_cycle_zero_fills_bucket_absent_from_first_pool() {
     let (_temp_dir, store) = setup_two_pool_scanner_store().await;
     let bucket = format!("scanner-second-pool-{}", Uuid::new_v4().simple());
@@ -359,6 +366,7 @@ fn object_lock_config_enabled_accepts_enabled_only() {
 }
 
 #[test]
+#[serial]
 fn dirty_usage_snapshot_clear_preserves_newer_generation() {
     clear_dirty_usage_buckets_for_tests();
     record_dirty_usage_bucket("photos");
@@ -373,6 +381,7 @@ fn dirty_usage_snapshot_clear_preserves_newer_generation() {
 }
 
 #[test]
+#[serial]
 fn dirty_usage_generation_acknowledgement_preserves_newer_mutations() {
     clear_dirty_usage_buckets_for_tests();
     record_dirty_usage_bucket("photos");
@@ -398,6 +407,7 @@ fn dirty_usage_generation_acknowledgement_preserves_newer_mutations() {
 }
 
 #[test]
+#[serial]
 fn dirty_usage_generation_acknowledgement_rejects_stale_process_and_future_generation() {
     clear_dirty_usage_buckets_for_tests();
     record_dirty_usage_bucket("photos");
@@ -427,6 +437,7 @@ fn dirty_usage_generation_acknowledgement_rejects_stale_process_and_future_gener
 }
 
 #[test]
+#[serial]
 fn dirty_usage_snapshot_detects_uncovered_generation() {
     clear_dirty_usage_buckets_for_tests();
     record_dirty_usage_bucket("photos");
@@ -451,6 +462,7 @@ fn generation_saturates_instead_of_wrapping() {
 }
 
 #[test]
+#[serial]
 fn dirty_usage_snapshot_clears_a_stably_absent_bucket_after_durable_save() {
     clear_dirty_usage_buckets_for_tests();
     record_dirty_usage_bucket("photos");
@@ -472,6 +484,7 @@ fn dirty_usage_snapshot_clears_a_stably_absent_bucket_after_durable_save() {
 }
 
 #[test]
+#[serial]
 fn dirty_usage_snapshot_preserves_an_absent_bucket_recorded_after_listing_started() {
     clear_dirty_usage_buckets_for_tests();
     let generation_before_bucket_list = dirty_usage_generation();
@@ -486,6 +499,7 @@ fn dirty_usage_snapshot_preserves_an_absent_bucket_recorded_after_listing_starte
 }
 
 #[test]
+#[serial]
 fn deleting_a_clean_bucket_invalidates_an_inflight_usage_snapshot() {
     clear_dirty_usage_buckets_for_tests();
     let snapshot = snapshot_dirty_usage_buckets(&[bucket_info("photos")], dirty_usage_generation());
@@ -499,6 +513,7 @@ fn deleting_a_clean_bucket_invalidates_an_inflight_usage_snapshot() {
 }
 
 #[test]
+#[serial]
 fn deleting_a_bucket_during_listing_invalidates_the_resulting_usage_snapshot() {
     clear_dirty_usage_buckets_for_tests();
     let generation_before_bucket_list = dirty_usage_generation();
@@ -512,6 +527,7 @@ fn deleting_a_bucket_during_listing_invalidates_the_resulting_usage_snapshot() {
 }
 
 #[test]
+#[serial]
 fn scanner_maintenance_change_advances_generation_and_marks_usage_dirty() {
     clear_dirty_usage_buckets_for_tests();
     let generation = scanner_maintenance_generation();
@@ -524,6 +540,7 @@ fn scanner_maintenance_change_advances_generation_and_marks_usage_dirty() {
 }
 
 #[test]
+#[serial]
 fn dirty_usage_clear_excludes_failed_buckets() {
     clear_dirty_usage_buckets_for_tests();
     record_dirty_usage_bucket("photos");
@@ -555,6 +572,7 @@ fn dirty_usage_clear_plan_excludes_cache_save_failures() {
 }
 
 #[test]
+#[serial]
 fn dirty_usage_is_acknowledged_only_after_durable_usage_confirmation() {
     clear_dirty_usage_buckets_for_tests();
     record_dirty_usage_bucket("photos");
@@ -572,6 +590,7 @@ fn dirty_usage_is_acknowledged_only_after_durable_usage_confirmation() {
 }
 
 #[test]
+#[serial]
 fn clear_dirty_usage_bucket_removes_deleted_bucket_marker() {
     clear_dirty_usage_buckets_for_tests();
     record_dirty_usage_bucket("photos");
@@ -898,30 +917,35 @@ async fn bucket_cache_pending_heal_reaches_cycle_maintenance_state() {
 }
 
 #[test]
+#[serial]
 fn scanner_concurrency_limit_preserves_available_when_unconfigured() {
     crate::reset_foreground_read_activity_for_test();
     assert_eq!(scanner_concurrency_limit(0, 4), 4);
 }
 
 #[test]
+#[serial]
 fn scanner_concurrency_limit_caps_to_configured_value() {
     crate::reset_foreground_read_activity_for_test();
     assert_eq!(scanner_concurrency_limit(2, 4), 2);
 }
 
 #[test]
+#[serial]
 fn scanner_concurrency_limit_never_exceeds_available_work() {
     crate::reset_foreground_read_activity_for_test();
     assert_eq!(scanner_concurrency_limit(8, 4), 4);
 }
 
 #[test]
+#[serial]
 fn scanner_concurrency_limit_handles_no_available_work() {
     crate::reset_foreground_read_activity_for_test();
     assert_eq!(scanner_concurrency_limit(2, 0), 0);
 }
 
 #[test]
+#[serial]
 fn scanner_concurrency_limit_yields_to_foreground_reads() {
     crate::reset_foreground_read_activity_for_test();
     crate::set_foreground_read_activity(8);
@@ -931,6 +955,7 @@ fn scanner_concurrency_limit_yields_to_foreground_reads() {
 }
 
 #[test]
+#[serial]
 fn scanner_concurrency_limit_yields_to_streaming_reads() {
     crate::reset_foreground_read_activity_for_test();
     let _guard = crate::ForegroundReadGuard::new();
@@ -954,6 +979,7 @@ fn increment_atomic_usize_saturates_at_max() {
 }
 
 #[test]
+#[serial]
 fn scanner_max_concurrent_set_scans_uses_env_cap() {
     with_var(ENV_SCANNER_MAX_CONCURRENT_SET_SCANS, Some("2"), || {
         crate::runtime_config::refresh_scanner_runtime_config_for_tests();
@@ -963,6 +989,7 @@ fn scanner_max_concurrent_set_scans_uses_env_cap() {
 }
 
 #[test]
+#[serial]
 fn scanner_max_concurrent_disk_scans_uses_env_cap() {
     with_var(ENV_SCANNER_MAX_CONCURRENT_DISK_SCANS, Some("1"), || {
         crate::runtime_config::refresh_scanner_runtime_config_for_tests();

crates/scanner/src/sleeper.rs

@@ -258,6 +258,7 @@ impl SleepTimer {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use serial_test::serial;
     use temp_env::{with_var, with_var_unset};
 
     struct ScannerDefaultSpeedGuard;
@@ -325,6 +326,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn test_refresh_from_env_applies_speed_and_idle_mode_for_next_cycle() {
         let prev_mode = SCANNER_IDLE_MODE.load(Ordering::Relaxed);
         SCANNER_IDLE_MODE.store(true, Ordering::Relaxed);
@@ -344,6 +346,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn test_refresh_from_env_uses_default_speed_override_when_speed_unset() {
         let _guard = ScannerDefaultSpeedGuard::set(ScannerSpeed::Slowest);
         let s = DynamicSleeper::new(ScannerSpeed::Default);
@@ -359,6 +362,7 @@ mod tests {
     }
 
     #[tokio::test(start_paused = true)]
+    #[serial]
     async fn test_fastest_never_sleeps() {
         let prev_mode = SCANNER_IDLE_MODE.load(Ordering::Relaxed);
         SCANNER_IDLE_MODE.store(true, Ordering::Relaxed);
@@ -372,6 +376,7 @@ mod tests {
     }
 
     #[tokio::test(start_paused = true)]
+    #[serial]
     async fn test_idle_mode_off_skips_sleep() {
         let prev_mode = SCANNER_IDLE_MODE.load(Ordering::Relaxed);
         SCANNER_IDLE_MODE.store(false, Ordering::Relaxed);

crates/scanner/tests/lifecycle_integration_test.rs

@@ -14,6 +14,7 @@
 
 #![recursion_limit = "256"]
 
+use futures::FutureExt;
 use rustfs_config::ENV_TEST_FORCE_IMMEDIATE_TRANSITION_ENQUEUE_TIMEOUT;
 use rustfs_scanner::scanner_folder::ScannerItem;
 use rustfs_scanner::scanner_io::ScannerIODisk;
@@ -22,8 +23,10 @@ use rustfs_scanner::{
     scanner::init_data_scanner,
 };
 use s3s::dto::RestoreRequest;
+use serial_test::serial;
 use std::{
     collections::HashMap,
+    env,
     path::{Path, PathBuf},
     sync::{Arc, Once, OnceLock},
     time::Duration,
@@ -532,15 +535,31 @@ async fn wait_for_transition(ecstore: &Arc<ECStore>, bucket: &str, object: &str,
     }
 }
 
-// Run `test_fn` with `ENV_TEST_FORCE_IMMEDIATE_TRANSITION_ENQUEUE_TIMEOUT`
-// set to `"1"` for its duration. `temp_env` serializes environment mutations
-// globally, preventing data races when multiple tests run in parallel.
+// SAFETY: this helper is used only by `#[serial]` tests and runs under the single-threaded Tokio
+// runtime (`worker_threads = 1`), so no concurrent test can mutate process environment during the
+// `env::set_var` / `env::remove_var` window.
+#[allow(unsafe_code)]
 async fn with_forced_immediate_enqueue_timeout<F, Fut>(test_fn: F)
 where
     F: FnOnce() -> Fut,
     Fut: std::future::Future<Output = ()>,
 {
-    temp_env::async_with_vars([(ENV_TEST_FORCE_IMMEDIATE_TRANSITION_ENQUEUE_TIMEOUT, Some("1"))], test_fn()).await;
+    let original = env::var_os(ENV_TEST_FORCE_IMMEDIATE_TRANSITION_ENQUEUE_TIMEOUT);
+    unsafe {
+        env::set_var(ENV_TEST_FORCE_IMMEDIATE_TRANSITION_ENQUEUE_TIMEOUT, "1");
+    }
+    let result = std::panic::AssertUnwindSafe(test_fn()).catch_unwind().await;
+    match original {
+        Some(value) => unsafe {
+            env::set_var(ENV_TEST_FORCE_IMMEDIATE_TRANSITION_ENQUEUE_TIMEOUT, value);
+        },
+        None => unsafe {
+            env::remove_var(ENV_TEST_FORCE_IMMEDIATE_TRANSITION_ENQUEUE_TIMEOUT);
+        },
+    }
+    if let Err(err) = result {
+        std::panic::resume_unwind(err);
+    }
 }
 
 mod serial_tests {
@@ -573,6 +592,7 @@ mod serial_tests {
     ///     body (GET won) or a clean object/version-not-found (expiry won). A
     ///     tier-fetch failure -- the #3491 symptom -- is never tolerated.
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    #[serial]
     #[ignore = "global-state ILM integration test: runs serialized in the CI ILM Integration (serial) lane, see ci.yml test-ilm-integration-serial and rustfs/backlog#1148 (ilm-2)"]
     async fn test_expire_transitioned_object_never_races_concurrent_get() {
         let (_disk_paths, ecstore) = setup_isolated_test_env(false).await;
@@ -718,6 +738,7 @@ mod serial_tests {
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    #[serial]
     #[ignore = "global-state ILM integration test: runs serialized in the CI ILM Integration (serial) lane, see ci.yml test-ilm-integration-serial"]
     async fn rejected_transition_candidate_is_recovered_from_persisted_delete_journal() {
         let (_disk_paths, ecstore) = setup_isolated_test_env(false).await;
@@ -804,6 +825,7 @@ mod serial_tests {
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    #[serial]
     #[ignore = "global-state ILM integration test: runs serialized in the CI ILM Integration (serial) lane, see ci.yml test-ilm-integration-serial"]
     async fn cancelled_before_cleanup_store_resolution_persists_journal() {
         let (_disk_paths, ecstore) = setup_isolated_test_env(false).await;
@@ -897,6 +919,7 @@ mod serial_tests {
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    #[serial]
     #[ignore = "global-state ILM integration test: runs serialized in the CI ILM Integration (serial) lane, see ci.yml test-ilm-integration-serial"]
     async fn rejected_transition_cleanup_durability_matrix() {
         #[derive(Clone, Copy)]
@@ -1036,6 +1059,7 @@ mod serial_tests {
     }
 
     #[test]
+    #[serial]
     #[ignore = "global-state ILM integration test: runs serialized in the CI ILM Integration (serial) lane, see ci.yml test-ilm-integration-serial and rustfs/backlog#1148 (ilm-1)"]
     fn test_transition_and_restore_flows() {
         std::thread::Builder::new()
@@ -1361,6 +1385,7 @@ mod serial_tests {
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    #[serial]
     #[ignore = "global-state ILM integration test: runs serialized in the CI ILM Integration (serial) lane, see ci.yml test-ilm-integration-serial and rustfs/backlog#1148 (ilm-1)"]
     async fn test_scanner_enqueues_free_version_cleanup_for_stale_transitioned_object() {
         let (disk_paths, ecstore) = setup_isolated_test_env(false).await;
@@ -1421,6 +1446,7 @@ mod serial_tests {
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    #[serial]
     #[ignore = "global-state ILM integration test: runs serialized in the CI ILM Integration (serial) lane, see ci.yml test-ilm-integration-serial and rustfs/backlog#1148 (ilm-1)"]
     async fn test_scanner_cleanup_still_works_after_immediate_compensation_transition() {
         let (disk_paths, ecstore) = setup_isolated_test_env(false).await;
@@ -1478,6 +1504,7 @@ mod serial_tests {
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    #[serial]
     #[ignore = "global-state ILM integration test: runs serialized in the CI ILM Integration (serial) lane, see ci.yml test-ilm-integration-serial and rustfs/backlog#1148 (ilm-1)"]
     async fn test_existing_object_backfill_is_idempotent_after_immediate_compensation_transition() {
         let (_disk_paths, ecstore) = setup_isolated_test_env(false).await;
@@ -1520,6 +1547,7 @@ mod serial_tests {
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    #[serial]
     #[ignore = "FAILING on main: excluded from the serial ILM lane pending a fix, see rustfs/backlog#1148 (ilm-1 partial)"]
     async fn test_noncurrent_expiry_still_works_after_immediate_compensation_transition() {
         let (disk_paths, ecstore) = setup_isolated_test_env(true).await;
@@ -1603,6 +1631,7 @@ mod serial_tests {
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    #[serial]
     #[ignore = "FAILING on main: excluded from the serial ILM lane pending a fix, see rustfs/backlog#1148 (ilm-1 partial)"]
     async fn test_noncurrent_transition_still_works_after_immediate_compensation_transition() {
         let (disk_paths, ecstore) = setup_isolated_test_env(true).await;
@@ -1685,6 +1714,7 @@ mod serial_tests {
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    #[serial]
     #[ignore = "global-state ILM integration test: runs serialized in the CI ILM Integration (serial) lane, see ci.yml test-ilm-integration-serial and rustfs/backlog#1148 (ilm-1)"]
     async fn test_modeled_versioned_delete_creates_delete_marker_after_immediate_compensation_transition() {
         let (_disk_paths, ecstore) = setup_isolated_test_env(true).await;
@@ -1732,6 +1762,7 @@ mod serial_tests {
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    #[serial]
     #[ignore = "global-state ILM integration test: runs serialized in the CI ILM Integration (serial) lane, see ci.yml test-ilm-integration-serial and rustfs/backlog#1148 (ilm-1)"]
     async fn test_modeled_delete_marker_cleanup_after_immediate_compensation_transition() {
         let (disk_paths, ecstore) = setup_isolated_test_env(true).await;
@@ -1808,6 +1839,7 @@ mod serial_tests {
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    #[serial]
     #[ignore = "global-state ILM integration test: runs serialized in the CI ILM Integration (serial) lane, see ci.yml test-ilm-integration-serial and rustfs/backlog#1148 (ilm-1)"]
     async fn test_scanner_expires_zero_day_current_version() {
         let (disk_paths, ecstore) = setup_isolated_test_env(false).await;
@@ -1834,6 +1866,7 @@ mod serial_tests {
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    #[serial]
     #[ignore = "global-state ILM integration test: runs serialized in the CI ILM Integration (serial) lane, see ci.yml test-ilm-integration-serial and rustfs/backlog#1148 (ilm-1)"]
     async fn test_put_object_immediately_enqueues_zero_day_current_expiry() {
         let (_disk_paths, ecstore) = setup_isolated_test_env(true).await;
@@ -1871,6 +1904,7 @@ mod serial_tests {
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    #[serial]
     #[ignore = "global-state ILM integration test: runs serialized in the CI ILM Integration (serial) lane, see ci.yml test-ilm-integration-serial and rustfs/backlog#1148 (ilm-1)"]
     async fn test_scanner_expires_zero_day_noncurrent_version() {
         let (disk_paths, ecstore) = setup_isolated_test_env(false).await;
@@ -1937,6 +1971,7 @@ mod serial_tests {
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    #[serial]
     #[ignore = "global-state ILM integration test: runs serialized in the CI ILM Integration (serial) lane, see ci.yml test-ilm-integration-serial and rustfs/backlog#1148 (ilm-1)"]
     async fn test_put_object_immediately_enqueues_zero_day_noncurrent_expiry() {
         let (_disk_paths, ecstore) = setup_isolated_test_env(true).await;
@@ -1997,6 +2032,7 @@ mod serial_tests {
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    #[serial]
     async fn test_background_scanner_expires_zero_day_current_version() {
         let (_disk_paths, ecstore) = setup_isolated_test_env(true).await;
 
@@ -2020,6 +2056,7 @@ mod serial_tests {
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    #[serial]
     #[ignore = "global-state ILM integration test: runs serialized in the CI ILM Integration (serial) lane, see ci.yml test-ilm-integration-serial and rustfs/backlog#1148 (ilm-1)"]
     async fn test_background_scanner_expires_zero_day_current_version_for_exact_key_prefix() {
         let (_disk_paths, ecstore) = setup_isolated_test_env(true).await;
@@ -2085,6 +2122,7 @@ mod serial_tests {
     /// tier object is untouched (zero `remove` calls) -> GET streams from the
     /// tier again -> a second restore succeeds.
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    #[serial]
     #[ignore = "global-state ILM integration test: runs serialized in the CI ILM Integration (serial) lane, see ci.yml test-ilm-integration-serial and rustfs/backlog#1148 (ilm-8)"]
     async fn test_restore_chain_local_read_expiry_keeps_remote_and_allows_re_restore() {
         let (_disk_paths, ecstore) = setup_test_env().await;
@@ -2216,6 +2254,7 @@ mod serial_tests {
     /// parts) must reassemble the exact part layout: part count and sizes,
     /// the multipart ETag, and byte-identical content across part boundaries.
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    #[serial]
     #[ignore = "global-state ILM integration test: runs serialized in the CI ILM Integration (serial) lane, see ci.yml test-ilm-integration-serial and rustfs/backlog#1148 (ilm-8)"]
     async fn test_multipart_restore_preserves_parts_and_etag() {
         let (_disk_paths, ecstore) = setup_test_env().await;

rustfs/src/admin/handlers/replication.rs

@@ -73,6 +73,8 @@ enum TargetUpdateOp {
     /// Connection group: credentials plus endpoint, target bucket, and TLS settings.
     Credentials,
     Sync,
+    /// Per-target read-proxy opt-out (`disableProxy`).
+    Proxy,
     Bandwidth,
     Path,
 }
@@ -81,12 +83,13 @@ fn parse_remote_target_update_ops(queries: &HashMap<String, String>) -> S3Result
     const SUPPORTED_OPS: &[(&str, TargetUpdateOp)] = &[
         ("creds", TargetUpdateOp::Credentials),
         ("sync", TargetUpdateOp::Sync),
+        ("proxy", TargetUpdateOp::Proxy),
         ("bandwidth", TargetUpdateOp::Bandwidth),
         ("path", TargetUpdateOp::Path),
     ];
     // Present in the MinIO wire contract, but they drive target fields this
     // version rejects as unsupported — fail loudly instead of silently ignoring.
-    const UNSUPPORTED_OPS: &[&str] = &["proxy", "healthcheck", "edge", "edgeSyncBeforeExpiry"];
+    const UNSUPPORTED_OPS: &[&str] = &["healthcheck", "edge", "edgeSyncBeforeExpiry"];
 
     for key in UNSUPPORTED_OPS {
         if queries.get(*key).is_some_and(|value| value == "true") {
@@ -312,11 +315,10 @@ impl RemoteTargetRequest {
             ));
         }
 
-        for (unsupported, configured) in
-            REMOTE_TARGET_UNSUPPORTED_FIELDS
-                .iter()
-                .copied()
-                .zip([self.disable_proxy, self.edge, self.edge_sync_before_expiry])
+        for (unsupported, configured) in REMOTE_TARGET_UNSUPPORTED_FIELDS
+            .iter()
+            .copied()
+            .zip([self.edge, self.edge_sync_before_expiry])
         {
             if configured {
                 return Err(s3_error!(
@@ -702,6 +704,7 @@ impl Operation for SetRemoteTargetHandler {
                         target.deployment_id = remote_target.deployment_id.clone();
                     }
                     TargetUpdateOp::Sync => target.replication_sync = remote_target.replication_sync,
+                    TargetUpdateOp::Proxy => target.disable_proxy = remote_target.disable_proxy,
                     TargetUpdateOp::Bandwidth => target.bandwidth_limit = remote_target.bandwidth_limit,
                     TargetUpdateOp::Path => target.path = remote_target.path.clone(),
                 }
@@ -1520,6 +1523,7 @@ mod tests {
             ("update", "true"),
             ("creds", "true"),
             ("sync", "true"),
+            ("proxy", "true"),
             ("bandwidth", "true"),
             ("path", "true"),
         ]))
@@ -1529,6 +1533,7 @@ mod tests {
             vec![
                 TargetUpdateOp::Credentials,
                 TargetUpdateOp::Sync,
+                TargetUpdateOp::Proxy,
                 TargetUpdateOp::Bandwidth,
                 TargetUpdateOp::Path
             ]
@@ -2070,7 +2075,6 @@ mod tests {
             ("credentials.session_token", serde_json::json!("session-token")),
             ("credentials.expiration", serde_json::json!("2026-01-01T00:00:00Z")),
             ("api", serde_json::json!("s3v2")),
-            ("disableProxy", serde_json::json!(true)),
             ("edge", serde_json::json!(true)),
             ("edgeSyncBeforeExpiry", serde_json::json!(true)),
         ] {
@@ -2300,6 +2304,44 @@ mod tests {
         assert!(!REMOTE_TARGET_UNSUPPORTED_FIELDS.contains(&"healthCheckDuration"));
     }
 
+    #[test]
+    fn remote_target_disable_proxy_is_declared_writable_edge_stays_unsupported() {
+        assert!(REMOTE_TARGET_WRITABLE_FIELDS.contains(&"disableProxy"));
+        assert!(!REMOTE_TARGET_UNSUPPORTED_FIELDS.contains(&"disableProxy"));
+        // edge sync has no implementation behind it — it must stay rejected.
+        assert!(REMOTE_TARGET_UNSUPPORTED_FIELDS.contains(&"edge"));
+        assert!(REMOTE_TARGET_UNSUPPORTED_FIELDS.contains(&"edgeSyncBeforeExpiry"));
+    }
+
+    #[test]
+    fn remote_target_create_accepts_disable_proxy() {
+        let mut request = valid_remote_target_request();
+        request["disableProxy"] = serde_json::json!(true);
+
+        let target = serde_json::from_value::<RemoteTargetRequest>(request)
+            .expect("request should deserialize")
+            .into_bucket_target()
+            .expect("disableProxy is a supported per-target read-proxy opt-out");
+
+        assert!(target.disable_proxy);
+    }
+
+    #[test]
+    fn update_body_with_proxy_op_toggles_disable_proxy_without_credentials() {
+        // Mirrors the other partial-update groups: a proxy-only update body may
+        // omit the connection fields entirely.
+        let body = serde_json::json!({
+            "arn": "arn:rustfs:replication:us-east-1:dep:target",
+            "type": "replication",
+            "disableProxy": true
+        });
+        let request: RemoteTargetRequest = serde_json::from_value(body).expect("partial update body should deserialize");
+        let target = request
+            .into_update_bucket_target(&[TargetUpdateOp::Proxy])
+            .expect("proxy-only update must not require credentials");
+        assert!(target.disable_proxy);
+    }
+
     #[test]
     fn remote_target_capability_fields_do_not_overlap() {
         for field in REMOTE_TARGET_UNSUPPORTED_FIELDS {

rustfs/src/admin/handlers/system.rs

@@ -1262,7 +1262,9 @@ mod tests {
         assert_eq!(response.summary.manual_transition_jobs.state, CapabilityState::Supported);
         assert_eq!(response.replication.contract_version, 1);
         assert_eq!(response.replication.bucket_replication.contract_version, 1);
-        assert_eq!(response.replication.remote_targets.contract_version, 1);
+        // v2: disableProxy moved from unsupported to writable (per-target
+        // read-proxy opt-out reached the admin API).
+        assert_eq!(response.replication.remote_targets.contract_version, 2);
         assert_eq!(response.replication.bucket_replication.status.state, CapabilityState::Supported);
         assert_eq!(response.replication.remote_targets.status.state, CapabilityState::Supported);
         assert_eq!(
@@ -1293,7 +1295,15 @@ mod tests {
                 .remote_targets
                 .fields
                 .iter()
-                .any(|field| field.name == "disableProxy" && field.state == super::ReplicationFieldState::Unsupported)
+                .any(|field| field.name == "disableProxy" && field.state == super::ReplicationFieldState::Supported)
+        );
+        assert!(
+            response
+                .replication
+                .remote_targets
+                .fields
+                .iter()
+                .any(|field| field.name == "edge" && field.state == super::ReplicationFieldState::Unsupported)
         );
         assert!(
             response
@@ -1364,7 +1374,7 @@ mod tests {
         assert_eq!(value["summary"]["manual_transition_jobs"]["state"], "supported");
         assert_eq!(value["replication"]["contract_version"], 1);
         assert_eq!(value["replication"]["bucket_replication"]["contract_version"], 1);
-        assert_eq!(value["replication"]["remote_targets"]["contract_version"], 1);
+        assert_eq!(value["replication"]["remote_targets"]["contract_version"], 2);
         assert_eq!(value["replication"]["bucket_replication"]["status"]["state"], "supported");
         assert_eq!(value["replication"]["remote_targets"]["status"]["state"], "supported");
         assert_eq!(
@@ -1383,7 +1393,14 @@ mod tests {
                 .as_array()
                 .expect("remote target fields should be an array")
                 .iter()
-                .any(|field| field["name"] == "disableProxy" && field["state"] == "unsupported")
+                .any(|field| field["name"] == "disableProxy" && field["state"] == "supported")
+        );
+        assert!(
+            value["replication"]["remote_targets"]["fields"]
+                .as_array()
+                .expect("remote target fields should be an array")
+                .iter()
+                .any(|field| field["name"] == "edge" && field["state"] == "unsupported")
         );
         assert!(
             value["replication"]["remote_targets"]["fields"]