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Date: Wed, 16 Apr 2008 10:43:39 -0500
From: Sagar Naik <sagar@visvo.com>
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To: core-user@hadoop.apache.org
Subject: Re: Aborting Map Function
References: <16722552.post@talk.nabble.com>
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Chaman Singh Verma wrote:
> Hello,
>
> I am developing one application with MapReduce and in that whenever some
> MapTask condition is 
> met, I would like to broadcast to all other MapTask to abort their work. I
> am not quite sure whether
> such broadcasting functionality currently exist in Hadoop MapReduce. Could
> someone give some
> hints.
>
> Although extending this functionality may be easy as all the slaves
> periodically ping the master,
> I was just thinking of piggybacking one bit information from the slave to
> the master and master
> may send this information to all the slaves in the next round. Any
> suggestions to this approach ?
>
> Thanks.
>
> With Regards 
>
> -----
> Chaman Singh Verma
> Poona, India
>   
One possible solution could be to use Counters 
(http://hadoop.apache.org/core/docs/r0.16.2/api/org/apache/hadoop/mapred/Counters.html)
Though it is advisable to look into details of implementation of it, and 
see if it can be used for multi-process shared variable