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From Apache Wiki <wikidi...@apache.org>
Subject [Hadoop Wiki] Update of "HadoopMapReduce" by DanielTunkelang
Date Thu, 09 Jul 2009 04:16:07 GMT
Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Hadoop Wiki" for change notification.

The following page has been changed by DanielTunkelang:
http://wiki.apache.org/hadoop/HadoopMapReduce

The comment on the change is:
updated links to deprecated Partitioner and HashPartitioner classes

------------------------------------------------------------------------------
  
  When Mapper output is collected it is partitioned, which means
  that it will be written to the output specified by the
- [http://hadoop.apache.org/core/docs/current/api/org/apache/hadoop/mapred/Partitioner.html
Partitioner]. The default [http://hadoop.apache.org/core/docs/current/api/org/apache/hadoop/mapred/lib/HashPartitioner.html
HashPartitioner] uses the
+ [http://hadoop.apache.org/core/docs/current/api/org/apache/hadoop/mapreduce/Partitioner.html
Partitioner]. The default [http://hadoop.apache.org/core/docs/current/api/org/apache/hadoop/mapreduce/lib/partition/HashPartitioner.html
HashPartitioner] uses the
  hashcode function on the key's class (which means that this hashcode function must be good
in order to achieve an even workload across the reduce tasks).  See [http://svn.apache.org/viewcvs.cgi/hadoop/core/trunk/src/mapred/org/apache/hadoop/mapred/MapTask.java?view=markup
 MapTask] for details.
  
  N input files will generate M map tasks to be run and each map

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