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From David Rosenstrauch <dar...@darose.net>
Subject Re: change number of slots in MR
Date Fri, 25 Mar 2011 19:25:15 GMT
On 03/25/2011 03:07 PM, Pedro Costa wrote:
> I don't know if this is what I want. I want to set the number of slots
> that are available for the map and the reduce tasks to run. I don't
> want to define the number of tasks.
>
> On Fri, Mar 25, 2011 at 6:44 PM, David Rosenstrauch<darose@darose.net>  wrote:
>> On 03/25/2011 02:26 PM, Pedro Costa wrote:
>>>
>>> Hi,
>>>
>>> is it possible to configure the total number of slots that a
>>> TaskTracker has, to run the map and reduce tasks?
>>>
>>> Thanks,
>>
>> Yes.  See the mapred.map.tasks and mapred.reduce.tasks settings.
>>
>> HTH,
>>
>> DR

Sorry, my mistake.

Set these in the mapred-site.xml file on each node:

<property>
   <name>mapred.tasktracker.reduce.tasks.maximum</name>
   <value>5</value>
</property>
<property>
   <name>mapred.tasktracker.map.tasks.maximum</name>
   <value>2</value>
</property>

(Obviously you'll need to change the values to what works for your 
environment.)

DR

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