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

@@ -75,7 +75,7 @@ pub struct BucketReplicationBandwidthStats {
 }
 
 #[derive(Debug, Clone, Default)]
-pub struct BucketReplicationStats {
+pub struct BucketReplicationMetricsSnapshot {
     pub bucket: String,
     pub total_failed_bytes: u64,
     pub total_failed_count: u64,
@@ -107,7 +107,7 @@ pub struct BucketReplicationStats {
 
 #[derive(Debug, Clone, Default)]
 pub(crate) struct BucketReplicationRuntimeStats {
-    pub(crate) stats: BucketReplicationStats,
+    pub(crate) stats: BucketReplicationMetricsSnapshot,
     pub(crate) target_flows: Vec<BucketReplicationTargetFlowStats>,
 }
 
@@ -182,7 +182,7 @@ fn push_proxy_request_result_metrics(
     }
 }
 
-pub fn collect_bucket_replication_metrics(stats: &[BucketReplicationStats]) -> Vec<PrometheusMetric> {
+pub fn collect_bucket_replication_metrics(stats: &[BucketReplicationMetricsSnapshot]) -> 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: BucketReplicationStats {
+            stats: BucketReplicationMetricsSnapshot {
                 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<BucketReplicationStats> = Vec::new();
+        let stats: Vec<BucketReplicationMetricsSnapshot> = 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, BucketReplicationStats, BucketReplicationTargetStats,
+    BucketReplicationBandwidthStats, BucketReplicationMetricsSnapshot, 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 ReplicationStats {
+pub struct ReplicationMetricsSnapshot {
     /// Average number of active replication workers
     pub average_active_workers: f64,
     /// Average queued bytes since server start
@@ -54,13 +54,13 @@ pub struct ReplicationStats {
 #[derive(Debug, Clone, Default)]
 pub(crate) struct ReplicationRuntimeStats {
     pub(crate) server: String,
-    pub(crate) stats: ReplicationStats,
+    pub(crate) stats: ReplicationMetricsSnapshot,
 }
 
 /// Collects replication metrics from the given stats.
 ///
 /// Returns a vector of Prometheus metrics for replication statistics.
-pub fn collect_replication_metrics(stats: &ReplicationStats) -> Vec<PrometheusMetric> {
+pub fn collect_replication_metrics(stats: &ReplicationMetricsSnapshot) -> 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 = ReplicationStats {
+        let stats = ReplicationMetricsSnapshot {
             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 = ReplicationStats::default();
+        let stats = ReplicationMetricsSnapshot::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 = ReplicationStats {
+        let stats = ReplicationMetricsSnapshot {
             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::BucketReplicationStats {
+            stats: crate::metrics::BucketReplicationMetricsSnapshot {
                 bucket: "photos".to_string(),
                 ..Default::default()
             },
             ..Default::default()
         }]);
         let current = repl_proxy_bucket_live_keys(&[BucketReplicationRuntimeStats {
-            stats: crate::metrics::BucketReplicationStats {
+            stats: crate::metrics::BucketReplicationMetricsSnapshot {
                 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,
-    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,
+    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,
 };
 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: BucketReplicationStats {
+        stats: BucketReplicationMetricsSnapshot {
             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() -> ReplicationStats {
+async fn obs_site_replication_stats() -> ReplicationMetricsSnapshot {
     let current_data_transfer_rate = obs_bucket_replication_bandwidth_stats()
         .into_iter()
         .flatten()
@@ -306,7 +306,7 @@ async fn obs_site_replication_stats() -> ReplicationStats {
         .sum::<f64>();
     let stats = obs_replication_site_stats_snapshot(current_data_transfer_rate).await;
 
-    ReplicationStats {
+    ReplicationMetricsSnapshot {
         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<BucketReplicationStats> {
+pub async fn collect_bucket_replication_detail_stats() -> Vec<BucketReplicationMetricsSnapshot> {
     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() -> ReplicationStats {
+pub async fn collect_replication_stats() -> ReplicationMetricsSnapshot {
     obs_site_replication_stats().await
 }