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Sunil G commented on YARN-3136: ------------------------------- HI [~jianhe] Specific tests are not needed for this. But we need to suppress few find bugs warnings for same. Kindly share your opinion {noformat} 1. Inconsistent synchronization of org.apache.hadoop.yarn.server.resourcemanager.scheduler.AbstractYarnScheduler.applications; locked 90% of time Synchronized 90% of the time Unsynchronized access at AbstractYarnScheduler.java:[line 138] Unsynchronized access at AbstractYarnScheduler.java:[line 162] Unsynchronized access at AbstractYarnScheduler.java:[line 230] 2. Inconsistent synchronization of org.apache.hadoop.yarn.server.resourcemanager.scheduler.AbstractYarnScheduler.rmContext; locked 95% of time Synchronized 95% of the time Unsynchronized access at AbstractYarnScheduler.java:[line 140] Unsynchronized access at AbstractYarnScheduler.java:[line 149] Synchronized access at AbstractYarnScheduler.java:[line 314] {noformat} > getTransferredContainers can be a bottleneck during AM registration > ------------------------------------------------------------------- > > Key: YARN-3136 > URL: https://issues.apache.org/jira/browse/YARN-3136 > Project: Hadoop YARN > Issue Type: Sub-task > Components: scheduler > Affects Versions: 2.6.0 > Reporter: Jason Lowe > Assignee: Sunil G > Attachments: 0001-YARN-3136.patch, 00010-YARN-3136.patch, > 0002-YARN-3136.patch, 0003-YARN-3136.patch, 0004-YARN-3136.patch, > 0005-YARN-3136.patch, 0006-YARN-3136.patch, 0007-YARN-3136.patch, > 0008-YARN-3136.patch, 0009-YARN-3136.patch > > > While examining RM stack traces on a busy cluster I noticed a pattern of AMs > stuck waiting for the scheduler lock trying to call getTransferredContainers. > The scheduler lock is highly contended, especially on a large cluster with > many nodes heartbeating, and it would be nice if we could find a way to > eliminate the need to grab this lock during this call. We've already done > similar work during AM allocate calls to make sure they don't needlessly grab > the scheduler lock, and it would be good to do so here as well, if possible. -- This message was sent by Atlassian JIRA (v6.3.4#6332)