chore(obs): rename ReplicationStats to ReplicationMetricsSnapshot (#6344)

* chore(obs): ReplicationStats -> ReplicationMetricsSnapshot, BucketReplicationStats -> BucketReplicationMetricsSnapshot

Rename in-obs-crate ReplicationStats and BucketReplicationStats to
ReplicationMetricsSnapshot and BucketReplicationMetricsSnapshot respectively.
No serde impact (these types are Prometheus metric collectors, not serialized).
No external consumers found outside the obs crate.

* cleanup: remove #[serial] annotations from e2e_test, scanner, lifecycle, and object-capacity crates

Remove no-op #[serial] attributes (nextest ignores serial_test) and the
serial_test dependency from four crates. All tests already use temp_env
for env-var isolation, making #[serial] purely redundant.

Crates cleaned:
- e2e_test (37 annotations, 9 imports, removed serial_test dep)
- rustfs-scanner (115 annotations across 7 files, removed serial_test dep)
- rustfs-lifecycle (46 annotations, removed serial_test dep)
- rustfs-object-capacity (38 annotations, removed serial_test dep)

Also converted scanner/tests/lifecycle_integration_test.rs
with_forced_immediate_enqueue_timeout helper from unsafe raw
env::set_var/remove_var to temp_env::async_with_vars for proper
isolation, and added async_closure feature to scanner's temp-env dep.

* fix(lifecycle): restore #[serial] on 2 tests that read env vars without temp_env

eval_inner_expires_latest_object_after_days_due and
eval_inner_does_not_panic_on_many_equal_due_events call eval_inner()
which reads ENV_ILM_PROCESS_TIME via std::env::var(). Without #[serial]
they race with other tests that set these vars via temp_env.

* style: cargo fmt

crates/e2e_test/Cargo.toml

@@ -96,7 +96,6 @@ 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

@@ -55,7 +55,6 @@ 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};
@@ -269,7 +268,6 @@ 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");
@@ -335,7 +333,6 @@ 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");
@@ -393,7 +390,6 @@ 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

@@ -51,7 +51,6 @@ 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;
@@ -129,7 +128,6 @@ 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

@@ -46,7 +46,6 @@ 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;
@@ -1695,7 +1694,6 @@ fn assert_storage_layout(
 }
 
 #[tokio::test]
-#[serial]
 async fn four_node_inline_storage_and_get_boundaries() -> TestResult {
     init_logging();
 
@@ -1767,7 +1765,6 @@ 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();
 
@@ -1805,7 +1802,6 @@ async fn four_node_empty_legacy_volumes_start_as_fresh() -> TestResult {
 }
 
 #[tokio::test]
-#[serial]
 async fn four_node_inline_fallback_controls() -> TestResult {
     init_logging();
 
@@ -1870,7 +1866,6 @@ async fn four_node_inline_fallback_controls() -> TestResult {
 }
 
 #[tokio::test]
-#[serial]
 async fn four_node_compressed_inline_fallback() -> TestResult {
     init_logging();
 
@@ -1905,7 +1900,6 @@ 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();
 
@@ -1952,7 +1946,6 @@ 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();
 
@@ -2019,7 +2012,6 @@ 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();
 
@@ -2123,7 +2115,6 @@ 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();
 
@@ -2142,7 +2133,6 @@ 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();
 
@@ -2164,7 +2154,6 @@ 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();
 
@@ -2239,7 +2228,6 @@ 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();
 
@@ -2381,7 +2369,6 @@ 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();
@@ -2486,7 +2473,6 @@ 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();
 
@@ -2598,7 +2584,6 @@ 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

@@ -19,7 +19,6 @@
 //! multipart upload behaviour.
 
 use crate::common::{TEST_BUCKET, init_logging};
-use serial_test::serial;
 use tokio::time::{Duration, sleep};
 use tracing::{error, info};
 
@@ -62,7 +61,6 @@ 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") {
@@ -118,7 +116,6 @@ 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") {
@@ -205,7 +202,6 @@ 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") {
@@ -270,7 +266,6 @@ 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") {
@@ -301,7 +296,6 @@ 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

@@ -17,7 +17,6 @@
 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
@@ -122,7 +121,6 @@ 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
@@ -275,7 +273,6 @@ 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
@@ -401,7 +398,6 @@ 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
@@ -491,7 +487,6 @@ 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
@@ -509,7 +504,6 @@ 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
@@ -705,7 +699,6 @@ 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

@@ -14,7 +14,6 @@
 
 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};
@@ -213,7 +212,6 @@ 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

@@ -41,7 +41,6 @@ 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;
 
@@ -821,7 +820,6 @@ 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

@@ -27,7 +27,6 @@ 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;
@@ -157,7 +156,6 @@ 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");
@@ -210,7 +208,6 @@ 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");
@@ -253,7 +250,6 @@ 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");
@@ -327,7 +323,6 @@ 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

@@ -29,7 +29,6 @@ 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;
@@ -1061,7 +1060,6 @@ 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>> {
@@ -1075,7 +1073,6 @@ 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>> {