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https://issues.apache.org/jira/browse/YARN-11191?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17577834#comment-17577834
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ASF GitHub Bot commented on YARN-11191:
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yb12138 commented on PR #4726:
URL: https://github.com/apache/hadoop/pull/4726#issuecomment-1210271008
@luoyuan3471
you can see this image.
this problem will occupy when refresh thread is calling
PreemptionManager.refreshQueue and schedule thread is calling
AbstractCSQueue.getTotalKillableResource.At this time, refresh thread will
require csqueue.readLock，but csqueue.readLock will blocked by schedule thread
and "other thread"( https://bugs.openjdk.org/browse/JDK-6893626 ).And schedule
thread will require PremmptionManager.readLock,but this readLock will blocked
by refresh thread held writeLock. so i use tryLock to make refresh thread get
csqueue.readLock. Wait for the refresh thread complete
PreemptionManager.refreshQueue,the schedule thread will get
premmptionManager.readLock, then can allocate new container.
> Global Scheduler refreshQueue cause deadLock
> ---------------------------------------------
>
> Key: YARN-11191
> URL: https://issues.apache.org/jira/browse/YARN-11191
> Project: Hadoop YARN
> Issue Type: Bug
> Components: capacity scheduler
> Affects Versions: 2.9.0, 3.0.0, 3.1.0, 2.10.0, 3.2.0, 3.3.0
> Reporter: ben yang
> Priority: Major
> Labels: pull-request-available
> Attachments: 1.jstack, YARN-11191.001.patch
>
>
> This is a potential bug may impact all open premmption cluster.In our
> current version with preemption enabled, the capacityScheduler will call the
> refreshQueue method of the PreemptionManager when it refreshQueue. This
> process hold the preemptionManager write lock and require csqueue read
> lock.Meanwhile,ParentQueue.canAssignToThisQueue will hold csqueue readLock
> and require PreemptionManager ReadLock.
> There is a possibility of deadlock at this time.Because readlock has one rule
> on unfair policy, when a lock is already occupied by a read lock and the
> first request in the lock competition queue is a write lock request,other
> read lock requests cann‘t acquire the lock.
> So the potential deadlock is:
> {code:java}
> CapacityScheduler.refreshQueue: hold: PremmptionManager.writeLock
> require: csqueue.readLock
> CapacityScheduler.schedule: hold: csqueue.readLock
> require: PremmptionManager.readLock
> other thread(completeContainer,release Resource,etc.): require:
> csqueue.writeLock
> {code}
> The jstack logs at the time were as follows
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