[jira] [Commented] (PIG-4043) JobClient.getMap/ReduceTaskReports() causes OOM for jobs with a large number of tasks

["Rohini Palaniswamy (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/PIG-4043?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14136742#comment-14136742 ] 

Rohini Palaniswamy commented on PIG-4043:
-----------------------------------------

bq.  In 0.12, there are no two copies of TaskReport arrays
  Actually. Even it has. The two arrays are inside JobClient.java in mapreduce though. 

> JobClient.getMap/ReduceTaskReports() causes OOM for jobs with a large number of tasks
> -------------------------------------------------------------------------------------
>
>                 Key: PIG-4043
>                 URL: https://issues.apache.org/jira/browse/PIG-4043
>             Project: Pig
>          Issue Type: Bug
>            Reporter: Cheolsoo Park
>            Assignee: Cheolsoo Park
>             Fix For: 0.14.0
>
>         Attachments: PIG-4043-1.patch, PIG-4043-2.patch, PIG-4043-3.patch, PIG-4043-4.patch, PIG-4043-5.patch, heapdump.png
>
>
> With Hadoop 2.4, I often see Pig client fails due to OOM when there are many tasks (~100K) with 1GB heap size.
> The heap dump (attached) shows that TaskReport[] occupies about 80% of heap space at the time of OOM.
> The problem is that JobClient.getMap/ReduceTaskReports() returns an array of TaskReport objects, which can be huge if the number of task is large.



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