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https://issues.apache.org/jira/browse/MAPREDUCE-1342?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Todd Lipcon updated MAPREDUCE-1342:
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Attachment: cycle0.png
Here's the output from jcarder that shows the cycle (this was detected while
running TestLostTracker with jcarder instrumentation using the branch at
http://github.com/toddlipcon/jcarder/tree/cloudera)
> Potential JT deadlock in faulty TT tracking
> -------------------------------------------
>
> Key: MAPREDUCE-1342
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-1342
> Project: Hadoop Map/Reduce
> Issue Type: Bug
> Components: jobtracker
> Affects Versions: 0.22.0
> Reporter: Todd Lipcon
> Attachments: cycle0.png
>
>
> JT$FaultyTrackersInfo.incrementFaults first locks potentiallyFaultyTrackers,
> and then calls blackListTracker, which calls removeHostCapacity, which locks
> JT.taskTrackers
> On the other hand, JT.blacklistedTaskTrackers() locks taskTrackers, then
> calls faultyTrackers.isBlacklisted() which goes on to lock
> potentiallyFaultyTrackers.
> I haven't produced such a deadlock, but the lock ordering here is inverted
> and therefore could deadlock.
> Not sure if this goes back to 0.21 or just in trunk.
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