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From Bejoy Ks <bejoy.had...@gmail.com>
Subject Re: Multiple reducers
Date Tue, 29 Nov 2011 14:45:14 GMT
Hi Hoot

You can specify the number of reducers explicitly using -D

hadoop jar wordcount.jar com.wc.WordCount –D mapred.reduce.tasks=n /input

Currenty your word count is triggering just 1 reducer because the defaukt
value of mapred.reduce.tasks woulld be set as 1 in your configuration file

Hope it helps !.


On Tue, Nov 29, 2011 at 8:03 PM, Hoot Thompson <hoot@ptpnow.com> wrote:

> I'm trying to prove that my cluster will in fact support multiple reducers,
> the wordcount example doesn't seem to spawn more that one (1). Is that
> correct? Is there a sure fire way to prove my cluster is configured
> correctly in terms of launching the maximum (say two per node) number of
> mappers and reducers?
> Thanks!

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