[ 
https://issues.apache.org/jira/browse/SPARK-2045?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14130974#comment-14130974
 ] 

Nicholas Chammas commented on SPARK-2045:
-----------------------------------------

The [1.1.0 release 
notes|http://spark.eu.apache.org/releases/spark-release-1-1-0.html] call out 
this change:

{quote}
"This “sort-based shuffle” will be become the default in the next release, and 
is now available to users. For jobs with large numbers of reducers, we 
recommend turning this on."
{quote}

Is turning this on just a matter of setting {{spark.shuffle.manager}} to 
{{SORT}}?

> Sort-based shuffle implementation
> ---------------------------------
>
>                 Key: SPARK-2045
>                 URL: https://issues.apache.org/jira/browse/SPARK-2045
>             Project: Spark
>          Issue Type: New Feature
>          Components: Shuffle, Spark Core
>            Reporter: Matei Zaharia
>            Assignee: Matei Zaharia
>             Fix For: 1.1.0
>
>         Attachments: Sort-basedshuffledesign.pdf
>
>
> Building on the pluggability in SPARK-2044, a sort-based shuffle 
> implementation that takes advantage of an Ordering for keys (or just sorts by 
> hashcode for keys that don't have it) would likely improve performance and 
> memory usage in very large shuffles. Our current hash-based shuffle needs an 
> open file for each reduce task, which can fill up a lot of memory for 
> compression buffers and cause inefficient IO. This would avoid both of those 
> issues.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org
For additional commands, e-mail: issues-h...@spark.apache.org

Reply via email to