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https://issues.apache.org/jira/browse/HADOOP-7761?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13136815#comment-13136815
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Hudson commented on HADOOP-7761:
--------------------------------

Integrated in Hadoop-Mapreduce-trunk-Commit #1179 (See 
[https://builds.apache.org/job/Hadoop-Mapreduce-trunk-Commit/1179/])
    HADOOP-7761. Improve the performance of raw comparisons. Contributed by 
Todd Lipcon.

todd : http://svn.apache.org/viewcvs.cgi/?root=Apache-SVN&view=rev&rev=1189613
Files : 
* /hadoop/common/trunk/hadoop-common-project/hadoop-common/CHANGES.txt
* 
/hadoop/common/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/FastByteComparisons.java
* 
/hadoop/common/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/WritableComparator.java

                
> Improve performance of raw comparisons
> --------------------------------------
>
>                 Key: HADOOP-7761
>                 URL: https://issues.apache.org/jira/browse/HADOOP-7761
>             Project: Hadoop Common
>          Issue Type: Improvement
>          Components: io, performance, util
>    Affects Versions: 0.23.0
>            Reporter: Todd Lipcon
>            Assignee: Todd Lipcon
>             Fix For: 0.24.0
>
>         Attachments: hadoop-7761.txt, hadoop-7761.txt, hadoop-7761.txt, 
> hadoop-7761.txt
>
>
> Guava has a nice implementation of lexicographical byte-array comparison that 
> uses sun.misc.Unsafe to compare unsigned byte arrays long-at-a-time. Their 
> benchmarks show it as being 2x more CPU-efficient than the equivalent 
> pure-Java implementation. We can easily integrate this into 
> WritableComparator.compareBytes to improve CPU performance in the shuffle.

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