You are viewing a plain text version of this content. The canonical link for it is here.

Posted to mapreduce-issues@hadoop.apache.org by "Thomas Graves (JIRA)" <ji...@apache.org> on 2011/07/20 15:44:58 UTC

[jira] [Updated] (MAPREDUCE-2705) tasks localized and launched serially by TaskLauncher - causing other tasks to be delayed

     [ https://issues.apache.org/jira/browse/MAPREDUCE-2705?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Thomas Graves updated MAPREDUCE-2705:
-------------------------------------

    Affects Version/s: 0.23.0
        Fix Version/s: 0.23.0
                       0.20.205.0

> tasks localized and launched serially by TaskLauncher - causing other tasks to be delayed
> -----------------------------------------------------------------------------------------
>
>                 Key: MAPREDUCE-2705
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-2705
>             Project: Hadoop Map/Reduce
>          Issue Type: Bug
>          Components: tasktracker
>    Affects Versions: 0.20.205.0, 0.23.0
>            Reporter: Thomas Graves
>            Assignee: Thomas Graves
>             Fix For: 0.20.205.0, 0.23.0
>
>
> The current TaskLauncher serially launches new tasks one at a time. During the launch it does the localization and then starts the map/reduce task.  This can cause any other tasks to be blocked waiting for the current task to be localized and started. In some instances we have seen a task that has a large file to localize (1.2MB) block another task for about 40 minutes. This particular task being blocked was a cleanup task which caused the job to be delayed finishing for the 40 minutes.

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira