Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Plain View
MapReduce >> mail # user >> No Mapper but Reducer

Bejoy KS 2011-09-07, 07:48
Sonal Goyal 2011-09-07, 07:52
Bejoy KS 2011-09-07, 08:00
Copy link to this message
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



From: Bejoy KS [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, September 07, 2011 1:30 PM
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,
Crux: Reporting <https://github.com/sonalgoyal/crux>  for HBase
Nube Technologies <http://www.nubetech.co>  

On Wed, Sep 7, 2011 at 1:18 PM, Bejoy KS <[EMAIL PROTECTED]> wrote:

          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




Harsh J 2011-09-07, 08:55
Sudharsan Sampath 2011-09-07, 09:39
Bejoy KS 2011-09-07, 11:21
Harsh J 2011-09-07, 11:39
Robert Hafner 2011-09-07, 16:33
GOEKE, MATTHEW 2011-09-07, 17:00
Bejoy KS 2011-09-08, 06:09
GOEKE, MATTHEW 2011-09-08, 14:40