[CELEBORN-2250] Fix lock contention in ReducePartitionCommitHandler.finishMapperAttempt via fine-grained locks#3586
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yew1eb wants to merge 2 commits intoapache:mainfrom
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[CELEBORN-2250] Fix lock contention in ReducePartitionCommitHandler.finishMapperAttempt via fine-grained locks#3586yew1eb wants to merge 2 commits intoapache:mainfrom
yew1eb wants to merge 2 commits intoapache:mainfrom
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Pull request overview
This pull request addresses lock contention issues in ReducePartitionCommitHandler.finishMapperAttempt by introducing fine-grained per-shuffle locks. The change replaces synchronization on the global shuffleMapperAttempts object with per-shuffle lock objects stored in a new shuffleIdLocks ConcurrentHashMap.
Changes:
- Added
shuffleIdLocksConcurrentHashMap to store per-shuffle lock objects - Updated
finishMapperAttemptto acquire per-shuffle locks instead of global lock - Updated
initMapperAttemptsto acquire per-shuffle locks instead of global lock
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RexXiong
reviewed
Jan 27, 2026
client/src/main/scala/org/apache/celeborn/client/commit/ReducePartitionCommitHandler.scala
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…ndler.finishMapperAttempt via fine-grained locks
SteNicholas
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Jan 27, 2026
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Pull request overview
Copilot reviewed 1 out of 1 changed files in this pull request and generated 2 comments.
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client/src/main/scala/org/apache/celeborn/client/commit/ReducePartitionCommitHandler.scala
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SteNicholas
approved these changes
Jan 27, 2026
SteNicholas
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Thanks for contribution. Merged to main(v0.7.0). |
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What changes were proposed in this pull request?
Add
shuffleIdLocks(fine-grained locks per shuffleId), replace globalshuffleMapperAttemptslock ininitMapperAttemptsandfinishMapperAttempt.Why are the changes needed?
High concurrency causes lock contention on
shuffleMapperAttemptsinfinishMapperAttempt, leading to abnormally long shuffle write time for small queries in Kyuubi Shared Mode. Fine-grained locks eliminate cross-shuffle blocking and improve concurrency.Does this PR resolve a correctness bug?
No.
Does this PR introduce any user-facing change?
No.
How was this patch tested?
CI.