hadoop-mapreduce-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Koji Noguchi (JIRA)" <j...@apache.org>
Subject [jira] Commented: (MAPREDUCE-114) All reducer tasks are finished, while some mapper tasks are still running
Date Thu, 11 Mar 2010 20:24:27 GMT

    [ https://issues.apache.org/jira/browse/MAPREDUCE-114?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12844220#action_12844220
] 

Koji Noguchi commented on MAPREDUCE-114:
----------------------------------------

Is this related to MAPREDUCE-1060 ?

> All reducer tasks are finished, while some mapper tasks are still running
> -------------------------------------------------------------------------
>
>                 Key: MAPREDUCE-114
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-114
>             Project: Hadoop Map/Reduce
>          Issue Type: Bug
>            Reporter: Qi Liu
>         Attachments: hadoop-bug-overview.png, hadoop-bug-useless-task.png
>
>
> In a high load environment (i.e. multiple jobs are queued up to be executed), when all
reducer tasks of a job are finished, some mapper tasks of the same job may still running (possibly
re-executed due to lost task tracker, etc).
> This should not happen when a job has at least one reducer task. When all reducer tasks
are in SUCCEEDED state, the Hadoop JobTracker should kill all running mapper tasks, since
execution would be meaningless. The job should also switch to SUCCEEDED state when all reducer
tasks of that job succeeded successfully.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message