[ 
https://issues.apache.org/jira/browse/MAPREDUCE-6447?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14692985#comment-14692985
 ] 

shuzhangyao commented on MAPREDUCE-6447:
----------------------------------------

the default mapreduce.reduce.shuffle.input.buffer.percent is 0.9,so memorylimit 
= Runtime.getRuntime().maxMemory() * 0.9 .
0.9*0.25*5=1.125>1.

> reduce shuffle throws "java.lang.OutOfMemoryError: Java heap space"
> -------------------------------------------------------------------
>
>                 Key: MAPREDUCE-6447
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-6447
>             Project: Hadoop Map/Reduce
>          Issue Type: Bug
>    Affects Versions: 2.5.0, 2.6.0, 2.5.1, 2.7.1
>            Reporter: shuzhangyao
>            Assignee: shuzhangyao
>            Priority: Minor
>
> 2015-08-11 14:03:54,550 WARN [main] org.apache.hadoop.mapred.YarnChild: 
> Exception running child : 
> org.apache.hadoop.mapreduce.task.reduce.Shuffle$ShuffleError: error in 
> shuffle in fetcher#10
>       at org.apache.hadoop.mapreduce.task.reduce.Shuffle.run(Shuffle.java:134)
>       at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:376)
>       at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:168)
>       at java.security.AccessController.doPrivileged(Native Method)
>       at javax.security.auth.Subject.doAs(Subject.java:415)
>       at 
> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1614)
>       at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:163)
> Caused by: java.lang.OutOfMemoryError: Java heap space
>       at 
> org.apache.hadoop.io.BoundedByteArrayOutputStream.<init>(BoundedByteArrayOutputStream.java:56)
>       at 
> org.apache.hadoop.io.BoundedByteArrayOutputStream.<init>(BoundedByteArrayOutputStream.java:46)
>       at 
> org.apache.hadoop.mapreduce.task.reduce.InMemoryMapOutput.<init>(InMemoryMapOutput.java:63)
>       at 
> org.apache.hadoop.mapreduce.task.reduce.MergeManagerImpl.unconditionalReserve(MergeManagerImpl.java:303)
>       at 
> org.apache.hadoop.mapreduce.task.reduce.MergeManagerImpl.reserve(MergeManagerImpl.java:293)
>       at 
> org.apache.hadoop.mapreduce.task.reduce.Fetcher.copyMapOutput(Fetcher.java:511)
>       at 
> org.apache.hadoop.mapreduce.task.reduce.Fetcher.copyFromHost(Fetcher.java:329)
>       at org.apache.hadoop.mapreduce.task.reduce.Fetcher.run(Fetcher.java:193)



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to