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https://issues.apache.org/jira/browse/MAPREDUCE-3971?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13225205#comment-13225205
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Bhallamudi Venkata Siva Kamesh commented on MAPREDUCE-3971:
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Hi Robert,
As per my understanding, */mapreduce/jobs* API causes a very large load on the
job history server. However, a user can mention limit also, ofcourse it can be
optional.
Intention of this ticket is to return only a limited number of items,
something like recent 50 or 100 among 20000, in the absense of limit factor or
irrespective of limit factor?
I think, suppose say a user mentions limit as 50, even then all the jobs from
*intermediateListCache* & *jobListCache* are being fetched from JHS and again
iterating over the list in the HsWebServices, to return only required number of
jobs. If so, I think, we can move the limit factor to JHS to parse only that
many jobs, some thing like following API will be useful
{noformat}
public Map<JobId, Job> getNJobs(String queue, String user, long sTime, long
sEnd, long fStart, long fEnd, int n) {}
{noformat}
Please provide your comments.
> Job History web services need to have limits on the number of itmes they can
> return.
> ------------------------------------------------------------------------------------
>
> Key: MAPREDUCE-3971
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-3971
> Project: Hadoop Map/Reduce
> Issue Type: Sub-task
> Components: mrv2
> Affects Versions: 0.23.2
> Reporter: Robert Joseph Evans
>
> The Job History web services canput a very large load on the job history
> server. We should put in a limit on the number of entries that can be
> returned by the web service, and also add in the ability to modify the
> starting location in the list, so that all entries can still be downlaoded.
> Just not all at once.
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