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From Abhishek <abhishek.dod...@gmail.com>
Subject Number of reducers
Date Tue, 28 Aug 2012 03:02:38 GMT
Hi all,

I just want to know that, based on what factor map reduce framework decides number of reducers
to launch for a job

By default only one reducer will be launched for a given job is this right? If we explicitly
does not mention number to launch via command line or driver class.

If i choose to decide number of reducers to mention explicitly, what should I consider.Because
choosing in appropriate number of reducer hampers the performance.

Sorry for this question, am little confused on this number of reducers.

Regards
Abhishek






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