[
https://issues.apache.org/jira/browse/MAPREDUCE-712?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12727808#action_12727808
]
Arun C Murthy commented on MAPREDUCE-712:
-----------------------------------------
bq. I wonder how much time you were spending in gc with such small heaps. That
might explain the cpu load.
Agreed. You have 5G of data per map (50TB/100k maps) which results in a
significant number of output Text objects being created in RandomTextWriter (a
potential bug).
Thus, we'd get a lot of data out of the profiles of the tasks...
> TextWritter example is CPU bound!!
> ----------------------------------
>
> Key: MAPREDUCE-712
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-712
> Project: Hadoop Map/Reduce
> Issue Type: Improvement
> Components: task
> Affects Versions: 0.20.1, 0.21.0
> Environment: ~200 nodes cluster
> Each node has the following configuration:
> Processors: 2 x Xeon L5420 2.50GHz (8 cores) - Harpertown C0, 64-bit,
> quad-core (8 CPUs)
> 4 Disks
> 16 GB RAM
> Linux 2.6
> Hadoop version: trunk
> Reporter: Khaled Elmeleegy
>
> Running the RandomTextWritter example job ( from the examples jar) pegs the
> machiens' CPUs.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
