hadoop-mapreduce-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Allen Wittenauer (JIRA)" <j...@apache.org>
Subject [jira] Commented: (MAPREDUCE-1266) Allow heartbeat interval smaller than 3 seconds for tiny clusters
Date Fri, 04 Dec 2009 22:45:20 GMT

    [ https://issues.apache.org/jira/browse/MAPREDUCE-1266?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12786213#action_12786213
] 

Allen Wittenauer commented on MAPREDUCE-1266:
---------------------------------------------

I'm probably be forgetful, but.. we have:

a) heartbeat interval
b) minimum heartbeat interval

such that

a > b, always.

If someone doesn't like b, does it matter?  Wouldn't they just tune a?  I guess i'm asking:
why make b configurable at all?

> Allow heartbeat interval smaller than 3 seconds for tiny clusters
> -----------------------------------------------------------------
>
>                 Key: MAPREDUCE-1266
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-1266
>             Project: Hadoop Map/Reduce
>          Issue Type: Improvement
>          Components: jobtracker, task, tasktracker
>    Affects Versions: 0.22.0
>            Reporter: Todd Lipcon
>            Priority: Minor
>
> For small clusters, the heartbeat interval has a large effect on job latency. This is
especially true on pseudo-distributed or other "tiny" (<5 nodes) clusters. It's not a big
deal for production, but new users would have a happier first experience if Hadoop seemed
snappier.
> I'd like to change the minimum heartbeat interval from 3.0 seconds to perhaps 0.5 seconds
(but have it governed by an undocumented config parameter in case people don't like this change).
The cluster size-based ramp up of interval will maintain the current scalable behavior for
large clusters with no negative effect.

-- 
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