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https://issues.apache.org/jira/browse/HADOOP-3442?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Chris Douglas updated HADOOP-3442:
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Attachment: 3442-1.patch
Proposed fix for 0.18:
* Resurrect map.sort.class property to control which sort implementation to
use, add HeapSort & BatcherSort as valid targets; keep QuickSort as the default
* Change QuickSort to recur only on the smaller partition (limits recursion
depth to log\(n))
* Change QuickSort to use HeapSort once it reaches an unreasonable recursion
depth (2*ceil(log\(n))) (Introspection Sort)
Fix for 0.17.1:
* Only fix the recursion. The degenerate cases for QuickSort with
median-of-three partitioning really are uncommon.
> QuickSort may get into unbounded recursion
> ------------------------------------------
>
> Key: HADOOP-3442
> URL: https://issues.apache.org/jira/browse/HADOOP-3442
> Project: Hadoop Core
> Issue Type: Bug
> Components: mapred
> Affects Versions: 0.17.0
> Reporter: Runping Qi
> Assignee: Chris Douglas
> Priority: Blocker
> Fix For: 0.17.1, 0.18.0
>
> Attachments: 3442-0.patch, 3442-0v17.patch, 3442-1.patch,
> CheckSortBuffer.java, HADOOP-3442.patch, overflow.zip, spillbuffers.patch
>
>
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