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Ray Chiang commented on YARN-3416: ---------------------------------- There probably is a bug here, but what value do you have for the property: mapreduce.job.reduce.slowstart.completedmaps in mapred-default.xml? If it's close to 0.0, I'd possibly suggest increasing it closer to 1.0 in order to keep the number of pending reducers down. This will likely have a performance hit, but should at least allow your job to complete. > deadlock in a job between map and reduce cores allocation > ---------------------------------------------------------- > > Key: YARN-3416 > URL: https://issues.apache.org/jira/browse/YARN-3416 > Project: Hadoop YARN > Issue Type: Bug > Components: fairscheduler > Affects Versions: 2.6.0 > Reporter: mai shurong > > I submit a big job, which has 500 maps and 350 reduce, to a > queue(fairscheduler) with 300 max cores. When the big mapreduce job is > running 100% maps, the 300 reduces have occupied 300 max cores in the queue. > And then, a map fails and retry, waiting for a core, while the 300 reduces > are waiting for failed map to finish. So a deadlock occur. As a result, the > job is blocked, and the later job in the queue cannot run because no > available cores in the queue. > I think there is the similar issue for memory of a queue . -- This message was sent by Atlassian JIRA (v6.3.4#6332)