crunch-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Gabriel Reid (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (CRUNCH-256) SequentialFileNamingScheme should cache the # of files in the target directory after the first read
Date Sat, 24 Aug 2013 05:50:52 GMT

    [ https://issues.apache.org/jira/browse/CRUNCH-256?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13749318#comment-13749318
] 

Gabriel Reid commented on CRUNCH-256:
-------------------------------------

+1
                
> SequentialFileNamingScheme should cache the # of files in the target directory after
the first read
> ---------------------------------------------------------------------------------------------------
>
>                 Key: CRUNCH-256
>                 URL: https://issues.apache.org/jira/browse/CRUNCH-256
>             Project: Crunch
>          Issue Type: Bug
>    Affects Versions: 0.7.0
>            Reporter: Josh Wills
>            Assignee: Josh Wills
>             Fix For: 0.8.0
>
>         Attachments: CRUNCH-256b.patch, CRUNCH-256.patch
>
>
> After a job finishes running, the post-job hooks rename the files from a temp output
directory to the target output directory. When we have lots of files, this move can take a
long time, and I traced the performance issue to the fact that SequentialFileNamingScheme
does a listStatus() on the output directory for every file that gets moved. If SequentialFileNamingScheme
just does this check once and then increments an internal counter, we can significantly decrease
the performance overhead involved with the move.

--
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

Mime
View raw message