[ 
https://issues.apache.org/jira/browse/MAPREDUCE-4469?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13493443#comment-13493443
 ] 

Philip Zeyliger commented on MAPREDUCE-4469:
--------------------------------------------

If you're looking for a resource usage of a process and its children, look at 
{{man getrusage}} which includes a flag to get the CPU usage of the children.  
Mind you, you'd need native code to get at it.
                
> Resource calculation in child tasks is CPU-heavy
> ------------------------------------------------
>
>                 Key: MAPREDUCE-4469
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-4469
>             Project: Hadoop Map/Reduce
>          Issue Type: Bug
>          Components: performance, task
>    Affects Versions: 1.0.3
>            Reporter: Todd Lipcon
>            Assignee: Ahmed Radwan
>         Attachments: MAPREDUCE-4469.patch, MAPREDUCE-4469_rev2.patch, 
> MAPREDUCE-4469_rev3.patch, MAPREDUCE-4469_rev4.patch
>
>
> In doing some benchmarking on a hadoop-1 derived codebase, I noticed that 
> each of the child tasks was doing a ton of syscalls. Upon stracing, I noticed 
> that it's spending a lot of time looping through all the files in /proc to 
> calculate resource usage.
> As a test, I added a flag to disable use of the ResourceCalculatorPlugin 
> within the tasks. On a CPU-bound 500G-sort workload, this improved total job 
> runtime by about 10% (map slot-seconds by 14%, reduce slot seconds by 8%)

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Reply via email to