[
https://issues.apache.org/jira/browse/MAPREDUCE-4907?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13540681#comment-13540681
]
Hadoop QA commented on MAPREDUCE-4907:
--------------------------------------
{color:red}-1 overall{color}. Here are the results of testing the latest
attachment
http://issues.apache.org/jira/secure/attachment/12562625/MAPREDUCE-4907.patch
against trunk revision .
{color:red}-1 patch{color}. The patch command could not apply the patch.
Console output:
https://builds.apache.org/job/PreCommit-MAPREDUCE-Build/3182//console
This message is automatically generated.
> TrackerDistributedCacheManager issues too many getFileStatus calls
> ------------------------------------------------------------------
>
> Key: MAPREDUCE-4907
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-4907
> Project: Hadoop Map/Reduce
> Issue Type: Bug
> Components: mrv1, tasktracker
> Affects Versions: 1.1.1
> Reporter: Sandy Ryza
> Assignee: Sandy Ryza
> Attachments: MAPREDUCE-4907.patch
>
>
> TrackerDistributedCacheManager issues a number of redundant getFileStatus
> calls when determining the timestamps and visibilities of files in the
> distributed cache. 300 distributed cache files deep in the directory
> structure can hammer HDFS with a couple thousand requests.
> A couple optimizations can reduce this load:
> 1. determineTimestamps and determineCacheVisibilities both call getFileStatus
> on every file. We could cache the results of the former and use them for the
> latter.
> 2. determineCacheVisibilities needs to check that all ancestor directories of
> each file have execute permissions for everyone. This currently entails a
> getFileStatus on each ancestor directory for each file. The results of these
> getFileStatus calls could be cached as well.
--
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
