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https://issues.apache.org/jira/browse/YARN-3139?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15517172#comment-15517172
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Wangda Tan commented on YARN-3139:
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Thanks [~asuresh] for the review, actually I'm working on the patch :)
bq. AbstractYarnScheduler::getApplicationAttempt() : Do you need the read lock
...
Agree, fixed
bq. AbstractYarnScheduler::moveAllApps() : Don't think we need a writelock...
The reason I put a writelock because we want the move operation to be
serialized, for example, it may have some issue when we do two moveAll
operation at the same time. To me moveApp is equivalent to remove the app and
add the new one. Same as we protect addAppAttempt, we should use the same
writelock for safety.
bq. SchedulerApplicationAttempt::pendingRelease :Maybe use a
ConcurrentSkipListSet ?
Unless we need to order the set, I think use ConcurrentHashSet should be
enough, SkiplistSet gets worse performance (O(logN) vs. O(1))
bq. Considering that initScheduler is called exactly once, and the Scheduler
cannot be used before it is initted, do we need a write lock there ?
I would prefer keep it just for safety and consistency, as it doesn't affect
performance. Same for stop and startSchedulerThreads
bq. FairScheduler 2.. 3..
Addressed
And [~jianhe],
I revisited {{checkSchedContainerChangeRequest}}, it is actually safe, so I
removed comment of the original method.
> Improve locks in AbstractYarnScheduler/CapacityScheduler/FairScheduler
> ----------------------------------------------------------------------
>
> Key: YARN-3139
> URL: https://issues.apache.org/jira/browse/YARN-3139
> Project: Hadoop YARN
> Issue Type: Sub-task
> Components: resourcemanager, scheduler
> Reporter: Wangda Tan
> Assignee: Wangda Tan
> Attachments: YARN-3139.0.patch, YARN-3139.1.patch, YARN-3139.2.patch
>
>
> Enhance locks in AbstractYarnScheduler/CapacityScheduler/FairScheduler, as
> mentioned in YARN-3091, a possible solution is using read/write lock. Other
> fine-graind locks for specific purposes / bugs should be addressed in
> separated tickets.
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