[ 
https://issues.apache.org/jira/browse/ACCUMULO-599?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13283364#comment-13283364
 ] 

Adam Fuchs commented on ACCUMULO-599:
-------------------------------------

Sounds like we ought to reach out to a Java GC guru with this question.

My philosophy would be that we should pull in whatever configs we think make 
sense and then thoroughly test. Waiting for bugs to show up could mask the 
potential for performance improvement.
                
> investigate permgen collection and class unloading with concurrent mark and 
> sweep garbage collector
> ---------------------------------------------------------------------------------------------------
>
>                 Key: ACCUMULO-599
>                 URL: https://issues.apache.org/jira/browse/ACCUMULO-599
>             Project: Accumulo
>          Issue Type: Bug
>          Components: scripts
>    Affects Versions: 1.3.6, 1.4.0
>            Reporter: Adam Fuchs
>            Assignee: John Vines
>
> The Java concurrent mark and sweep garbage collector appears to default to 
> not unloading classes or sweeping the permgen storage space. Accumulo reloads 
> classes dynamically, potentially contributing a lot to the permgen space. It 
> is important that these classes be garbage collected when we're done with 
> them. Since we use -XX:+UseConcMarkSweepGC by default for all Accumulo 
> processes, should we also use -XX:+CMSClassUnloadingEnabled and 
> -XX:+CMSPermGenSweepingEnabled? Are there other flags or parameters that we 
> should set to really do java garbage collection properly in a long-lived 
> instance?
> These should be set in conf/accumulo-env.sh as part of ACCUMULO_GENERAL_OPTS.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: 
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Reply via email to