[Hadoop Wiki] Update of "FAQ" by Arun C Murthy

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The following page has been changed by Arun C Murthy:
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The comment on the change is:
Fixed FAQ# 13

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  '''13. [#13 MR. I see a maximum of 2 maps/reduces spawned concurrently on each TaskTracker, how do I increase that?]'''
  
- Use the configuration knob: [http://hadoop.apache.org/core/docs/current/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'', hence one sees a maximum of 2 maps and 2 reduces at a given instance on a !TaskTracker.
+ Use the configuration knob: [http://hadoop.apache.org/core/docs/current/hadoop-default.html#mapred.tasktracker.map.tasks.maximum mapred.tasktracker.map.tasks.maximum] and [http://hadoop.apache.org/core/docs/current/hadoop-default.html#mapred.tasktracker.reduce.tasks.maximum mapred.tasktracker.reduce.tasks.maximum] to control the number of maps/reduces spawned simultaneously on a !TaskTracker. By default, it is set to ''2'', hence one sees a maximum of 2 maps and 2 reduces at a given instance on a !TaskTracker.
  
+ You can set those on a per-tasktracker basis to accurately reflect your hardware (i.e. set those to higher nos. on a beefier tasktracker etc.).
- 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 (independently). [http://issues.apache.org/jira/browse/HADOOP-1274 HADOOP-1274] should fix that.
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