[jira] [Updated] (PIG-4505) [Pig on Tez] Auto adjust AM memory can hit OOM with 3.5GXmx

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

     [ https://issues.apache.org/jira/browse/PIG-4505?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Rohini Palaniswamy updated PIG-4505:
------------------------------------
    Attachment: PIG-4505-1.patch

AM creates one thread for each nodemanager it needs to talk to and can be high in a big cluster with more nodes when number of tasks is high requiring more native memory (thread stack size). More threads will not only use up pmem, but also will allocate lot more vmem most of which mostly go unused. In fact jdk8 and 64bit jvms use lot more virtual address space. Since pmem-vmem ratio is turned off in Hadoop 2.x, virtual address space usage exceeding container size or pmem-vmem ratio is not an issue. But with 32-bit jvm, jvm cannot go beyond 4G limit for allocating virtual address space and that is where it hits the problem. So need to keep the heap size small giving room for it to not hit 4G limit.

> [Pig on Tez] Auto adjust AM memory can hit OOM with 3.5GXmx
> -----------------------------------------------------------
>
>                 Key: PIG-4505
>                 URL: https://issues.apache.org/jira/browse/PIG-4505
>             Project: Pig
>          Issue Type: Bug
>            Reporter: Rohini Palaniswamy
>            Assignee: Rohini Palaniswamy
>             Fix For: 0.15.0
>
>         Attachments: PIG-4505-1.patch
>
>
>   If the cluster is big and can launch many containers, Tez can try to create more threads to talk to the nodes and that can cause java.lang.OutOfMemoryError: unable to create new native thread as there is only 512MB of native memory (4GB limit due to 32-bit jvm) to create threads. 



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