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MapReduce >> mail # user >> No Mapper but Reducer


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Bejoy KS 2011-09-07, 07:48
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Sonal Goyal 2011-09-07, 07:52
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Bejoy KS 2011-09-07, 08:00
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RE: No Mapper but Reducer
Hi Bejoy,

 

    It is possible to execute a job with no mappers and reducers alone.

 

You can try this by giving the empty directory as input for the job.

 

Devaraj K

 

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From: Bejoy KS [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, September 07, 2011 1:30 PM
To: [EMAIL PROTECTED]
Subject: Re: No Mapper but Reducer

 

Thanks Sonal. I was just thinking of some weird design and wanted to make
sure whether there is a possibility like that- no maps and all reducers.

On Wed, Sep 7, 2011 at 1:22 PM, Sonal Goyal <[EMAIL PROTECTED]> wrote:

I dont think that is possible, can you explain in what scenario you want to
have no mappers, only reducers?
Best Regards,
Sonal
Crux: Reporting <https://github.com/sonalgoyal/crux>  for HBase
Nube Technologies <http://www.nubetech.co>  

 <http://in.linkedin.com/in/sonalgoyal>
On Wed, Sep 7, 2011 at 1:18 PM, Bejoy KS <[EMAIL PROTECTED]> wrote:

Hi
          I'm having a query here. Is it possible to have no mappers but
reducers alone? AFAIK If we need to avoid the tyriggering of reducers we can
set numReduceTasks to zero but such a setting on mapper wont work. So how
can it be achieved if possible?

Thank You

Regards
Bejoy.K.S

 

 

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Harsh J 2011-09-07, 08:55
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Sudharsan Sampath 2011-09-07, 09:39
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Bejoy KS 2011-09-07, 11:21
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Harsh J 2011-09-07, 11:39
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Robert Hafner 2011-09-07, 16:33
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GOEKE, MATTHEW 2011-09-07, 17:00
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Bejoy KS 2011-09-08, 06:09
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GOEKE, MATTHEW 2011-09-08, 14:40
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB