venkata91 opened a new pull request #33896:
URL: https://github.com/apache/spark/pull/33896
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### What changes were proposed in this pull request?
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As part of SPARK-32920 implemented a simple approach to finalization for
push-based shuffle. Shuffle merge finalization is the final operation happens
at the end of the stage when all the tasks are completed asking all the
external shuffle services to complete the shuffle merge for the stage. Once
this request is completed no more shuffle pushes will be accepted. With this
approach, `DAGScheduler` waits for a fixed time of 10s
(`spark.shuffle.push.finalize.timeout`) to allow some time for the inflight
shuffle pushes to complete, but this adds additional overhead to stages with
very little shuffles.
In this PR, instead of waiting for fixed amount of time before shuffle merge
finalization now this is controlled adaptively if min threshold number of map
tasks shuffle push (`spark.shuffle.push.minPushRatio`) completed then shuffle
merge finalization will be scheduled. Also additionally if the total shuffle
generated is lesser than min threshold shuffle size
(`spark.shuffle.push.minShuffleSizeToWait`) then immediately shuffle merge
finalization is scheduled.
### Why are the changes needed?
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This is a performance improvement to the existing functionality
### Does this PR introduce _any_ user-facing change?
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Yes additional user facing configs `spark.shuffle.push.minPushRatio` and
`spark.shuffle.push.minShuffleSizeToWait`
### How was this patch tested?
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Added unit tests in `DAGSchedulerSuite`
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