[
https://issues.apache.org/jira/browse/HADOOP-2764?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12566177#action_12566177
]
Joydeep Sen Sarma commented on HADOOP-2764:
-------------------------------------------
> The JVM doesn't generally use more heap unless it has to. Are you seeing
> datanodes and tasktrackers that use a lot of memory?
No - i don't think the tasktrackers and datanodes consume a lot of memory. i am
just being paranoid - from what i have read and seen - the resident memory is
affected by the heap size setting. Garbage collection is less aggressive if
there is a lot of headroom in the heap. So in general it seems like a good
thing to set the heap size close to what's required.
> specify different heap size for namenode/jobtracker vs. tasktracker/datanodes
> -----------------------------------------------------------------------------
>
> Key: HADOOP-2764
> URL: https://issues.apache.org/jira/browse/HADOOP-2764
> Project: Hadoop Core
> Issue Type: New Feature
> Affects Versions: 0.15.3
> Reporter: Joydeep Sen Sarma
> Priority: Minor
>
> tasktrackers/datanodes should be run with low memory settings. theres a lot
> of competition for memory on slave nodes and these tasks don't need much
> memory anyway and best to keep heap setting low.
> namenode needs higher memory and there's usually lots to spare on separate
> box.
> hadoop-env.sh can provide different heap settings for central vs. slave
> daemons.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
