[
https://issues.apache.org/jira/browse/HADOOP-2752?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Owen O'Malley resolved HADOOP-2752.
-----------------------------------
Resolution: Duplicate
Fix Version/s: 0.16.0
This was fixed by HADOOP-2131.
> Ability to turn on/off speculative execution for maps/reduces separately
> ------------------------------------------------------------------------
>
> Key: HADOOP-2752
> URL: https://issues.apache.org/jira/browse/HADOOP-2752
> Project: Hadoop Core
> Issue Type: New Feature
> Components: mapred
> Affects Versions: 0.15.3
> Reporter: Joydeep Sen Sarma
> Fix For: 0.16.0
>
>
> Motivation is obvious:
> - sometimes reduces have side-effects - but maps don't (for example reduces
> compute something and write it somewhere)
> - want to turn ON speculative for maps (because maps are usually way less
> expensive. map progress counters are reliable etc.) - but OFF for reduces
> (very expensive to run two reducers instead of one).
> It's also likely that in future you may want different setting for
> speculative triggers for maps and reduces ... (but that's a different issue).
> I will submit a patch (since we are putting this into effect on our cluster -
> and it seems simple enough :-)).
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
