You are viewing a plain text version of this content. The canonical link for it is here.
Posted to common-dev@hadoop.apache.org by "Arun C Murthy (JIRA)" <ji...@apache.org> on 2007/10/12 14:03:51 UTC
[jira] Updated: (HADOOP-1721) Rack-aware Shuffle
[ https://issues.apache.org/jira/browse/HADOOP-1721?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Arun C Murthy updated HADOOP-1721:
----------------------------------
Fix Version/s: 0.15.0
Affects Version/s: 0.14.2
Status: Patch Available (was: Open)
> Rack-aware Shuffle
> ------------------
>
> Key: HADOOP-1721
> URL: https://issues.apache.org/jira/browse/HADOOP-1721
> Project: Hadoop
> Issue Type: Improvement
> Components: mapred
> Affects Versions: 0.14.2
> Reporter: Arun C Murthy
> Assignee: Arun C Murthy
> Fix For: 0.15.0
>
>
> We could try and experiment with *rack-aware* scheduling of fetches per-reducer. Given the disparities between in-rack and off-rack bandwidth it could be a improvement to do something along these lines:
> {noformat}
> if (no. of known map-output locations > than no. of copier threads) {
> try to schedule 75% of copies off-rack
> try schedule 25% of copies in-rack
> }
> {noformat}
> This could lead to better utilization of both in-rack & switch b/w...
> Clearly we want to schedule more cross-switch than in-rack since off-rack copies will take significantly more time; hence the 75-25 split.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.