rustfs/crates/ecstore/src/bucket/replication

ECStore Replication Split Inventory

This directory still owns the ECStore replication workers. The resync status contracts and wire format now live in rustfs-replication, while worker runtime code still depends on ECStore object IO, bucket target clients, bucket metadata systems, runtime state, notification events, and lifecycle/heal scheduling paths.

Current Modules

Module	Current role	Split blocker
config.rs	Replication config helpers, rule matching, and tag filtering.	Uses replication-local filemeta/tagging boundaries and S3 DTOs directly.
replication_object_decision_boundary.rs	Object replication option DTOs, resync target projection, delete replication decisions, and multipart planning helpers.	Keeps ECStore runtime modules from importing object decision contracts directly from rustfs-replication.
replication_pool.rs	Replication queue, worker pool, MRF persistence, bucket stats, and delete/object scheduling.	Depends on bucket target sys, bucket metadata sys, metadata paths, queue contracts through the queue boundary, file metadata replication contracts through local boundaries, config storage, storage contracts through the replication storage boundary, runtime sources, and notification state.
replication_proxy.rs	Proxy-target selection for GET/HEAD/Tagging reads of objects not yet replicated locally (MinIO getProxyTargets parity: anti-loop, version-suspended, and no-config empty branches).	Uses replication config lookup, rule matching, and target clients through local boundaries.
replication_queue_boundary.rs	Queue/admission DTOs, heal queue DTOs, worker sizing, and backpressure helpers.	Keeps ECStore runtime modules from importing queue/backpressure contracts directly from rustfs-replication.
replication_resync_boundary.rs	Resync DTOs, status classifiers, persisted resync/MRF codec wrappers, and ECStore error mapping.	Keeps ECStore runtime modules from importing resync contract helpers directly from rustfs-replication.
replication_resyncer.rs	Object replication, delete replication, resync execution, target calls, and multipart target upload paths.	Depends on target calls and target config types through the replication target boundary, metadata paths and metadata systems through the replication metadata boundary, file metadata replication contracts through the filemeta boundary, object decisions and multipart planning through the object decision boundary, resync contracts through the resync boundary, queue DTOs through the queue boundary, error contracts through the error boundary, versioning systems, storage contracts through the replication storage boundary, config-derived storage class labels through the config store, runtime sources, notification events and local event host selection through the event sink, bandwidth reader wrapping, and SetDisks lock timing.
replication_state.rs	Replication queue/stat state and worker accounting.	Reads stats DTOs through the stats boundary, runtime sources, file metadata replication contracts, error contracts, and bucket monitor handles through local boundaries, and owns shared replication pool/stat state.
replication_stats_boundary.rs	Bucket replication stats DTOs, queue/proxy metric caches, and worker metric snapshots.	Keeps ECStore runtime modules from importing stats contracts directly from rustfs-replication.
replication_lifecycle_bridge.rs	Lifecycle-originated delete replication admission and version-purge state construction.	Depends on replication config/rule matching, delete-replication decisions, and replication delete scheduling through a local contract type.
replication_migration_bridge.rs	Bucket migration access to persisted replication resync codec helpers.	Keeps migration normalization behind a bridge instead of re-exporting resyncer codec helpers.
replication_object_bridge.rs	App and SetDisks object replication decisions plus object/delete scheduling.	Keeps object write/delete replication call sites behind a bridge instead of exporting low-level resyncer and pool helpers.
replication_scanner_bridge.rs	Scanner-originated replication heal admission.	Keeps scanner-facing heal queueing behind a local contract type instead of exporting the internal queue function directly.
replication_target_config_bridge.rs	Bucket target removal checks against replication target rules.	Keeps bucket target sys from importing replication config helper types directly.
rule.rs	Rule evaluation helpers for object replication options.	Depends on ECStore replication object option types.
mod.rs	Explicit compatibility re-export facade for the current ECStore owner.	Wildcard re-exports are guarded so internal helpers do not leak back into the public facade.

Required Contracts

Contract	Responsibility	Current dependency to remove
ReplicationObjectIO	Object read/write primitives used by config, MRF, resync status, and multipart replication paths.	ECStore object API reader/writer types and storage-api object IO contracts are concentrated in replication_storage_boundary.rs.
ReplicationStorage	Object read/write/delete, object walk, metadata update, and target object IO.	ECStore object API, storage-api contracts, and read option types are concentrated in replication_storage_boundary.rs.
ReplicationMetadataStore	Replication config, MRF/resync state, target reset headers, and status persistence.	Metadata sys access and replication metadata path constants are exposed through the contract type in replication_metadata_boundary.rs; versioning sys and config storage imports remain separate contracts.
EcstoreReplicationBoundaryImports	ECStore-side imports from rustfs-replication.	Direct rustfs-replication imports under crates/ecstore/src/bucket/replication stay in *_boundary.rs modules, including config and resync facade re-exports.
RuntimeReplicationFacadeConsumers	Runtime owner consumers of replication DTOs and status types.	Scanner, admin, and storage owner facades import replication DTOs/status types through rustfs-ecstore; app storage keeps the remaining direct object/delete helper calls behind its local storage API boundary.
ReplicationResyncContracts	Resync options, target status, bucket status, status classifiers, and persisted resync/MRF status wire format.	Owned by crates/replication; ECStore imports them through replication_resync_boundary.rs, which maps crate errors to ECStore errors.
ReplicationCrateFileMetaIndependence	Replication status, decision, MRF, resync, and target-reset wire contracts owned by rustfs-replication.	crates/replication/src/filemeta.rs owns these contracts; rustfs-replication must not import or depend on rustfs-filemeta.
ReplicationConfigStore	Replication config persistence and config-derived labels used by target options.	Config read/save helpers and storage class labels are exposed through the contract type in replication_config_store.rs.
ReplicationFileMeta	ECStore compatibility conversions for filemeta replication state/status.	rustfs_filemeta to rustfs_replication conversions are concentrated in replication_filemeta_boundary.rs; FileInfo remains in the storage boundary for storage trait bindings and walk options.
StorageApiReplicationContracts	Storage-api delete DTO replication state/status helpers.	Storage-api owner DTOs keep their local replication boundary; ECStore converts them in replication_storage_boundary.rs before queueing replication work.
ReplicationCrateStorageApiIndependence	Delete work DTOs consumed by rustfs-replication.	crates/replication/src/storage_api.rs owns these DTOs; rustfs-replication must not import or depend on rustfs-storage-api.
ReplicationObjectDecisionContracts	Object replication options, delete replication decisions, resync target projection, multipart planning, and delete-marker retry classifiers.	Owned by crates/replication; ECStore imports them through replication_object_decision_boundary.rs.
ReplicationQueueContracts	Queue admission, heal queue results/actions, worker operations, worker sizing, and backpressure decisions.	Owned by crates/replication; ECStore imports them through replication_queue_boundary.rs.
ReplicationStatsContracts	Bucket stats, replication target stats, queue/proxy metrics, and worker metric snapshots.	Owned by crates/replication; ECStore imports them through replication_stats_boundary.rs.
ReplicationErrorBoundary	ECStore error/result contracts and replication-specific error classifiers.	crate::error imports are concentrated in replication_error_boundary.rs.
ReplicationTargetStore	Bucket target listing, target client lookup, target offline checks, target config types, target operation option types, and target HeadObject comparison adapters.	Bucket target sys access, BucketTargets, target operation types, and HeadObject-to-replication DTO adapters are exposed through the contract type in replication_target_boundary.rs.
ReplicationRuntime	Worker pool, queue sizing, stats, bucket monitor, local node identity, cancellation, and admission state.	Direct runtime source/global access and shared replication pool/stat state; ECStore object store and bucket monitor implementation types stay behind local storage/bandwidth boundaries.
ReplicationBandwidthLimiter	Target reader wrapping for replication bandwidth accounting and throttling.	Direct bucket bandwidth reader imports from resyncer paths.
ReplicationEventSink	Notification and audit events for skipped, failed, pending, and completed replication operations.	Event notification service calls and local event host selection are concentrated in replication_event_sink.rs.
ReplicationVersioningStore	Versioning state checks for object and delete replication decisions.	Bucket versioning sys access is exposed through the contract type in replication_versioning_boundary.rs.
ReplicationLockTiming	Namespace lock timing for replication resync, object replication, and delete replication locks.	SetDisks lock timeout access is exposed through the contract type in replication_lock_boundary.rs.
ReplicationMsgpCodec	MessagePack time encode/decode and unknown value skipping for persisted resync/MRF state.	Bucket MessagePack helpers are exposed through the contract type in replication_msgp_boundary.rs.
ReplicationTagFilter	Decode object tag strings for rule and metadata replication decisions.	Bucket tagging helper access is exposed through the contract type in replication_tagging_boundary.rs.
ReplicationLifecycleBridge	Lifecycle-originated delete and version-purge scheduling.	Lifecycle delete paths call the bridge contract in replication_lifecycle_bridge.rs instead of constructing replication delete work directly.
ReplicationMigrationBridge	Persisted resync status decode/encode access for bucket metadata migration.	Bucket migration calls the bridge contract in replication_migration_bridge.rs instead of importing internal resyncer codec helpers.
ReplicationObjectBridge	Object write/delete replication decision and scheduling entry point for app storage and SetDisks paths.	App and SetDisks object paths call the bridge contract in replication_object_bridge.rs instead of importing internal resyncer/pool helpers.
ReplicationScannerBridge	Scanner-originated replication heal scheduling.	Scanner heal paths call the bridge contract in replication_scanner_bridge.rs instead of importing the internal queue function directly.
ReplicationTargetConfigBridge	Bucket target removal checks against replication target rules.	Bucket target sys calls the bridge contract in replication_target_config_bridge.rs instead of importing replication config helper types directly.

Migration Rules

1. Do not move bucket/replication into a new crate while workers import bucket target sys, metadata sys, runtime sources, bandwidth reader, notification services, or SetDisks lock timing directly.
2. Keep existing queue behavior, MRF persistence, resync state, target client semantics, notification/audit events, and scanner/heal classifications unchanged during inventory and contract PRs.
3. Keep the current ReplicationStorage trait as the starting point. Split it only after call sites prove a narrower object read/write/delete/walk shape.
4. Preserve rustfs_ecstore::api::bucket::replication compatibility until lifecycle, scanner, OBS, heal, and tests compile through replacement paths.
5. Keep imports between modules in this directory relative to the local replication module, not crate::bucket::replication::* self paths.
6. Keep runtime source access from importing ECStore object store or bucket monitor implementation types directly; use local boundary-owned aliases.
7. Move at most one owner boundary per code-bearing PR and verify it with focused replication tests before broad gates. Non-behavioral contract-shape cleanup may batch already-established boundary wrappers when the owner and call semantics do not change.
8. Keep the compatibility facade in mod.rs as an explicit symbol list. Do not reintroduce wildcard re-exports for replication implementation modules.
9. Keep object write/delete replication helpers behind ReplicationObjectBridge; do not export internal resyncer or pool scheduling helpers through the compatibility facade.
10. Keep ECStore owner modules outside bucket/replication behind bridge contracts when they need replication codec or config helper behavior.
11. Keep storage-api replication status/state helpers behind crates/storage-api/src/replication.rs; ECStore converts owner DTOs at the replication storage boundary.
12. Keep rustfs-replication independent from rustfs-filemeta; ECStore compatibility conversions live in replication_filemeta_boundary.rs.
13. Keep rustfs-replication independent from rustfs-storage-api; ECStore compatibility conversions live in replication_storage_boundary.rs.
14. Keep direct rustfs-replication imports inside ECStore replication concentrated in *_boundary.rs modules.
15. Keep scanner, admin, and storage-owner replication status/DTO consumers behind the ECStore replication facade; only rustfs/src/app/storage_api.rs may retain direct object/delete replication helper calls.

Completion Criteria

The split is complete when the "Current dependency to remove" column in the Required Contracts table above is empty: every row is either deleted because the dependency is gone, or reduced to "none". No other signal — file count, boundary count, line count — measures completion.

Target end state:

• replication_pool.rs, replication_resyncer.rs, and replication_state.rs move into crates/replication behind the contracts above;
• the *_boundary.rs and *_bridge.rs micro-files dissolve naturally as the code they fence moves across the crate boundary. They are the mechanical seams of the migration ratchet — the architecture guard scripts anchor on their file names — so batch-merging them beforehand is explicitly rejected: it forces synchronized guard-script/mod/import churn with zero functional gain;
• datatypes.rs retired early (its sanctioned exception): it was a pure relay (boundary -> datatypes -> mod.rs), so the facade now re-exports ResyncStatusType from the resync boundary directly and the relay file is deleted. Note the original retirement wording ("consumers import through rustfs-replication directly") conflicted with Migration Rule #15 — consumers stay behind the ECStore facade; only the relay hop dissolves.

Milestones

Milestone	Scope	Status
M0	Record the completion criteria and end state (this section).	Done
M1	Contract extraction: resync/queue/stats/object-decision/filemeta/storage wire contracts owned by crates/replication; ECStore imports concentrated in *_boundary.rs; event sink and runtime access behind local contracts.	Done — see Required Contracts
M2	Move resyncer pure decision logic (no IO) into crates/replication.	Done — moved the pure decision helpers with their unit tests: resync_status_duration (resync), resync_existing_delete_replication_info / replicate_delete_outcome / target_delete_version_id / delete_marker_purge_version_id / delete_marker_purge_mrf_entry (delete), version_identity_drifted / is_replication_target_offline_error / the SSE-C passthrough gate family incl. SsecPassthroughCapability (object; ssec_passthrough_evidence_present was param-demoted to the echoed customer-algorithm string, ECStore keeps the HeadObjectOutput adapter). ECStore imports them through the resync/object-decision/target boundaries; bucket_target_sys keeps only the verdict cache + TTL and re-exports the capability enum. Not moved (signatures carry ECStore or aws-sdk types): verify_resync_head_result, resync_target_error_detail, the SdkError classifiers (has_raw_status, is_version_id_format_mismatch), the replicate_all_* option/info builders, and bounded_resync_max_jobs (itself a pure clamp, but it forms one local configuration unit with the env-reading configured_resync_max_jobs and its ECStore-local constants — moving the clamp alone has negative value).
M3	Move the worker runtime (replication_pool.rs, the IO paths of replication_resyncer.rs, replication_state.rs) once the contract traits are stable. Highest-risk step of the whole plan; do it last.	Pending
M4	Retire the boundary modules together with their guard-script entries.	Pending (datatypes.rs already retired early alongside M2)

The original first code-bearing step (narrow ReplicationEventSink / ReplicationRuntime contracts) has landed — replication_event_sink.rs exists and runtime access goes through local boundary aliases — so new work starts from M2.

Current compatibility guard: crates/ecstore/tests/replication_facade_compat_test.rs keeps the ECStore replication facade types covered while architecture rules keep direct imports behind local storage_api boundaries.