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Hudson commented on YARN-4416: ------------------------------ FAILURE: Integrated in Hadoop-trunk-Commit #8978 (See [https://builds.apache.org/job/Hadoop-trunk-Commit/8978/]) YARN-4416. Deadlock due to synchronised get Methods in AbstractCSQueue. (wangda: rev 9b856d9787be5ec88ef34574b9b98755d7b669ea) * hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/LeafQueue.java * hadoop-yarn-project/CHANGES.txt * hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/AbstractCSQueue.java > Deadlock due to synchronised get Methods in AbstractCSQueue > ----------------------------------------------------------- > > Key: YARN-4416 > URL: https://issues.apache.org/jira/browse/YARN-4416 > Project: Hadoop YARN > Issue Type: Sub-task > Components: capacity scheduler, resourcemanager > Affects Versions: 2.7.1 > Reporter: Naganarasimha G R > Assignee: Naganarasimha G R > Priority: Minor > Attachments: YARN-4416.v1.001.patch, YARN-4416.v1.002.patch, > YARN-4416.v2.001.patch, YARN-4416.v2.002.patch, YARN-4416.v2.003.patch, > deadlock.log > > > While debugging in eclipse came across a scenario where in i had to get to > know the name of the queue but every time i tried to see the queue it was > getting hung. On seeing the stack realized there was a deadlock but on > analysis found out that it was only due to *queue.toString()* during > debugging as {{AbstractCSQueue.getAbsoluteUsedCapacity}} was synchronized. > Hence we need to ensure following : > # queueCapacity, resource-usage has their own read/write lock hence > synchronization is not req > # numContainers is volatile hence synchronization is not req. > # read/write lock could be added to Ordering Policy. Read operations don't > need synchronized. So {{getNumApplications}} doesn't need synchronized. > (First 2 will be handled in this jira and the third will be handled in > YARN-4443) -- This message was sent by Atlassian JIRA (v6.3.4#6332)