执行hive内存溢出

错误日志：

Diagnostic Messages for this Task:

Error: java.lang.OutOfMemoryError: Java heap space
at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.shuffleInMemory(ReduceTask.java:1703)
at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.getMapOutput(ReduceTask.java:1563)
at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.copyOutput(ReduceTask.java:1401)
at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.run(ReduceTask.java:1333)




FAILED: Execution Error, return code 2 from org.apache.hadoop.hive.ql.exec.MapRedTask
MapReduce Jobs Launched: 
Job 0: Map: 10  Reduce: 3   Cumulative CPU: 3035.3 sec   HDFS Read: 2528366258 HDFS Write: 1209449 FAIL

Total MapReduce CPU Time Spent: 50 minutes 35 seconds 300 msec

解决方法：

Solution:
  Currently hive.map.aggr.hash.percentmemory is set to 0.5. Try setting it to a lower value. i.e "set hive.map.aggr.hash.percentmemory = 0.25;"
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