[
https://issues.apache.org/jira/browse/SPARK-983?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14025637#comment-14025637
]
Madhu Siddalingaiah commented on SPARK-983:
-------------------------------------------
I made more progress over the weekend. I have the merge sort working reliably
and passing all sorting tests. The only things left are to read/write blocks to
disk (I'm developing all in-memory so far) and add spill conditions. I hope to
get it finalized in the next few days and submit the PR.
> Support external sorting for RDD#sortByKey()
> --------------------------------------------
>
> Key: SPARK-983
> URL: https://issues.apache.org/jira/browse/SPARK-983
> Project: Spark
> Issue Type: New Feature
> Affects Versions: 0.9.0
> Reporter: Reynold Xin
> Assignee: Madhu Siddalingaiah
>
> Currently, RDD#sortByKey() is implemented by a mapPartitions which creates a
> buffer to hold the entire partition, then sorts it. This will cause an OOM if
> an entire partition cannot fit in memory, which is especially problematic for
> skewed data. Rather than OOMing, the behavior should be similar to the
> [ExternalAppendOnlyMap|https://github.com/apache/spark/blob/master/core/src/main/scala/org/apache/spark/util/collection/ExternalAppendOnlyMap.scala],
> where we fallback to disk if we detect memory pressure.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
