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Gera Shegalov commented on MAPREDUCE-5649: ------------------------------------------ Thanks [~jlowe] for review and commit. Thanks [~jerrychenhf] for your patch in MAPREDUCE-4883, I resolve it as a duplicate. > Reduce cannot use more than 2G memory for the final merge > ---------------------------------------------------------- > > Key: MAPREDUCE-5649 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-5649 > Project: Hadoop Map/Reduce > Issue Type: Bug > Components: mrv2 > Reporter: stanley shi > Assignee: Gera Shegalov > Fix For: 2.8.0 > > Attachments: MAPREDUCE-5649.001.patch, MAPREDUCE-5649.002.patch, > MAPREDUCE-5649.003.patch > > > In the org.apache.hadoop.mapreduce.task.reduce.MergeManagerImpl.java file, in > the finalMerge method: > int maxInMemReduce = (int)Math.min( > Runtime.getRuntime().maxMemory() * maxRedPer, Integer.MAX_VALUE); > > This means no matter how much memory user has, reducer will not retain more > than 2G data in memory before the reduce phase starts. -- This message was sent by Atlassian JIRA (v6.3.4#6332)