perf(MongoDB): reduce allocations and improve robustness in lock hot paths - #276
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…paths - Cache IMongoCollection<T> reference in constructor instead of calling GetCollection on every TryAcquireAsync invocation - Promote immutable BsonDocument sub-expressions (expiredOrMissing, newFencingToken) to static readonly fields; cache newExpiresAt as an instance field (depends on expiry) to avoid rebuilding ~10 BsonDocument objects per busy-wait iteration - Move TTL index initialization to the start of TryAcquireAsync so it is triggered on every acquisition attempt, not only on success - Cache ownerFilter and renewUpdate in InnerHandle constructor; lease renewal (~every 10 s) no longer allocates new filter/update objects - Wrap ReleaseLockAsync in try-catch so network failures during Dispose do not surface unexpected exceptions to callers (TTL index provides eventual cleanup) - Add internal constructor accepting pre-parsed MongoDistributedLockOptions so MongoDistributedSynchronizationProvider can parse options once and reuse the result across all CreateLock calls - Fix stale comment "foo" → "expiresAt" in CheckIfIndexExists - Upgraded Microsoft.SourceLink.GitHub, Microsoft.Build.Tasks.Git, and Microsoft.SourceLink.Common to version 10.0.201 in DistributedLock.ZooKeeper, DistributedLock, and DistributedLockTaker. - Updated System.IO.Hashing to version 10.0.5 and added its dependencies. - Increased MongoDB.Bson and MongoDB.Driver versions to 3.7.1. - Updated System.Diagnostics.DiagnosticSource to version 10.0.5. - Adjusted DistributedLock.Oracle and DistributedLock.SqlServer versions to 1.0.5 and 1.0.7 respectively. - Made various transitive dependency updates to ensure compatibility and stability.
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Pull request overview
This PR optimizes the MongoDB-based distributed lock implementation to reduce per-acquire/renew allocations and improve operational robustness (TTL index creation timing, safer dispose behavior), while also updating several NuGet dependencies across the solution.
Changes:
- MongoDB lock hot-path optimizations: cache
IMongoCollection, reuse BSON sub-expressions, and cache renewal filter/update definitions. - Robustness adjustments: trigger TTL index initialization on every acquisition attempt; make release-on-dispose resilient to transient failures.
- Dependency refresh: bump MongoDB driver/BSON, SourceLink/build tooling, DiagnosticSource, System.IO.Hashing, and related transitive pins across projects.
Reviewed changes
Copilot reviewed 18 out of 18 changed files in this pull request and generated 5 comments.
Show a summary per file
| File | Description |
|---|---|
| src/DistributedLock.MongoDB/MongoDistributedLock.cs | Caches collection/expressions and reduces allocations in acquire/renew; adjusts TTL init timing; swallows release failures on dispose. |
| src/DistributedLock.MongoDB/MongoIndexInitializer.cs | Makes index-creation helper static and fixes TTL index existence check logic. |
| src/DistributedLock.MongoDB/MongoDistributedSynchronizationProvider.cs | Parses Mongo lock options once in provider and reuses them when creating locks. |
| src/Directory.Packages.props | Central version bumps (e.g., MongoDB.Driver, SourceLink, DiagnosticSource). |
| src/DistributedLock.MongoDB/packages.lock.json | Updates locked dependency graph for MongoDB package changes. |
| src/DistributedLock/packages.lock.json | Updates locked dependency graph for core package changes (SourceLink/System.IO.Hashing/etc.). |
| src/DistributedLock.Azure/packages.lock.json | Updates locked dependency graph for Azure package changes and transitive updates. |
| src/DistributedLock.Core/packages.lock.json | Updates locked dependency graph (notably SourceLink/System.IO.Hashing changes). |
| src/DistributedLock.FileSystem/packages.lock.json | Updates locked dependency graph for SourceLink/System.IO.Hashing and transitive updates. |
| src/DistributedLock.MySql/packages.lock.json | Updates locked dependency graph for SourceLink/System.IO.Hashing and transitive updates. |
| src/DistributedLock.Oracle/packages.lock.json | Updates locked dependency graph for SourceLink/System.IO.Hashing and transitive updates. |
| src/DistributedLock.Postgres/packages.lock.json | Updates locked dependency graph for SourceLink/System.IO.Hashing and transitive updates. |
| src/DistributedLock.Redis/packages.lock.json | Updates locked dependency graph for SourceLink/System.IO.Hashing and transitive updates. |
| src/DistributedLock.SqlServer/packages.lock.json | Updates locked dependency graph for SourceLink/System.IO.Hashing and transitive updates. |
| src/DistributedLock.Tests/packages.lock.json | Updates locked dependency graph for tests (now only contains net8.0 graph). |
| src/DistributedLock.WaitHandles/packages.lock.json | Updates locked dependency graph for SourceLink/System.IO.Hashing and transitive updates. |
| src/DistributedLock.ZooKeeper/packages.lock.json | Updates locked dependency graph for SourceLink/System.IO.Hashing and transitive updates. |
| src/DistributedLockTaker/packages.lock.json | Updates locked dependency graph (MongoDB driver and other dependency pins). |
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…ockDocument>> for improved initialization
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…ecks in MongoIndexInitializer
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