[
https://issues.apache.org/jira/browse/HADOOP-2141?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12675304#action_12675304
]
Devaraj Das commented on HADOOP-2141:
-------------------------------------
bq. I wanted to double check with Devaraj that you didn't add any new
functionality or bug fixes in your patch, but instead that it was just merging
with trunk
No, it was a plain merge
bq. In particular I noticed some properties that your patch adds to
mapred-default.xml that don't seem to be related to this JIRA or used in the
rest of the patch (e.g. mapred.shuffle.maxFetchPerHost). Were these included
intentionally?
Sorry these shouldn't have been there. I meant to just include the configs you
added.
> speculative execution start up condition based on completion time
> -----------------------------------------------------------------
>
> Key: HADOOP-2141
> URL: https://issues.apache.org/jira/browse/HADOOP-2141
> Project: Hadoop Core
> Issue Type: Improvement
> Components: mapred
> Affects Versions: 0.19.0
> Reporter: Koji Noguchi
> Assignee: Andy Konwinski
> Attachments: 2141.patch, HADOOP-2141-v2.patch, HADOOP-2141-v3.patch,
> HADOOP-2141-v4.patch, HADOOP-2141-v5.patch, HADOOP-2141.patch
>
>
> We had one job with speculative execution hang.
> 4 reduce tasks were stuck with 95% completion because of a bad disk.
> Devaraj pointed out
> bq . One of the conditions that must be met for launching a speculative
> instance of a task is that it must be at least 20% behind the average
> progress, and this is not true here.
> It would be nice if speculative execution also starts up when tasks stop
> making progress.
> Devaraj suggested
> bq. Maybe, we should introduce a condition for average completion time for
> tasks in the speculative execution check.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
