[ 
https://issues.apache.org/jira/browse/MAPREDUCE-1608?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12847195#action_12847195
 ] 

Hong Tang commented on MAPREDUCE-1608:
--------------------------------------

Interesting usage case. Are there other tasks running on the same node as the 
lone reduce task? If yes, are they slower than their peers and perhaps that 
would be an indication the node is ill-behaving and all tasks on that node 
should be speculatively executed?

> Allow users to do speculative execution of a task manually
> ----------------------------------------------------------
>
>                 Key: MAPREDUCE-1608
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-1608
>             Project: Hadoop Map/Reduce
>          Issue Type: New Feature
>            Reporter: Scott Chen
>            Assignee: Scott Chen
>
> Speculative execution improves the latency of the job. Sometimes the job has 
> few very slow reducers. Spending a little more resource on speculative tasks 
> can improve the latency a lot. It will be nice that the users can manually 
> select one task and force the speculative execution on that task just like we 
> can manually kill/fail task.
> The proposal is add link says "speculate" in taskdetails.jsp page where we do 
> "kill/fail".
> Thoughts? 

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

Reply via email to