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From Apache Wiki <wikidi...@apache.org>
Subject [Lucene-hadoop Wiki] Update of "FAQ" by Arun C Murthy
Date Sat, 06 Oct 2007 10:48:02 GMT
Dear Wiki user,

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

The following page has been changed by Arun C Murthy:
http://wiki.apache.org/lucene-hadoop/FAQ

The comment on the change is:
Added a section on how to control maximum concurrent tasks on a tasktracker

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  Learn more about safe mode
  [http://lucene.apache.org/hadoop/api/org/apache/hadoop/dfs/NameNode.html#setSafeMode(org.apache.hadoop.dfs.FSConstants.SafeModeAction)
   here].
  
+ 
+ [[BR]]
+ [[Anchor(13)]]
+ '''13. [#13 I see a maximum of 2 maps/reduces spawned on each TaskTracker, how do I increase
that?]'''
+ 
+ Use the configuration knob: [http://lucene.apache.org/hadoop/hadoop-default.html#mapred.tasktracker.tasks.maximum
mapred.tasktracker.tasks.maximum] to control the number of maps/reduces spawned simultaneously
on a !TaskTracker. By default, it is set to ''2''.
+ 
+ Caveats:
+    * ''mapred.tasktracker.tasks.maximum'' that is a cluster-wide limit i.e. controlled at
the !JobTracker end. [http://issues.apache.org/jira/browse/HADOOP-1245 HADOOP-1245] should
fix that.
+    * ''mapred.tasktracker.tasks.maximum'' controls the number of maps '''and''' number of
reduces. [http://issues.apache.org/jira/browse/HADOOP-1274 HADOOP-1274] should fix that.
+ 

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