[
https://issues.apache.org/jira/browse/MAPREDUCE-5785?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13924923#comment-13924923
]
Karthik Kambatla commented on MAPREDUCE-5785:
---------------------------------------------
Good idea. Thanks for filing and working on this, [~jira.shegalov]. What are
your thoughts on having a constant headroom (say, 200 MB) instead of a ratio?
Also, it would be nice to pick mapreduce.task.io.sort.mb automatically using a
ratio, by default. Would be nice to do that too.
> Derive task attempt JVM max heap size automatically from mapreduce.*.memory.mb
> ------------------------------------------------------------------------------
>
> Key: MAPREDUCE-5785
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-5785
> Project: Hadoop Map/Reduce
> Issue Type: New Feature
> Components: mr-am, task
> Reporter: Gera Shegalov
> Assignee: Gera Shegalov
> Attachments: MAPREDUCE-5785.v01.patch
>
>
> Currently users have to set 2 memory-related configs for per Job / per task
> type. One fist choses some container size mapreduce.*.memory.mb and then a
> corresponding Xmx < mapreduce.*.memory.mb to make sure that the JVM with the
> user code heap, and its native memory do not exceed this limit. If one
> forgets to tune Xmx, MR-AM might be allocating big containers whereas the JVM
> will only use the default -Xmx200m.
> With this JIRA, we propose to set Xmx automatically base on an empirical
> ratio that can be adjusted. Xmx is not changed automaically if provided by
> the user.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
