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Jason Lowe commented on MAPREDUCE-5027: --------------------------------------- AFAIK there is no built-in way to have Netty automatically limit the number of active client connections. A quick search on the net indicates one way this is handled is to simply close the extra connections as soon as they are created once we get past a specified number of active connections. > Shuffle does not limit number of outstanding connections > -------------------------------------------------------- > > Key: MAPREDUCE-5027 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-5027 > Project: Hadoop Map/Reduce > Issue Type: Bug > Affects Versions: 2.0.3-alpha, 0.23.5 > Reporter: Jason Lowe > > The ShuffleHandler does not have any configurable limits to the number of > outstanding connections allowed. Therefore a node with many map outputs and > many reducers in the cluster trying to fetch those outputs can exhaust a > nodemanager out of file descriptors. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira