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MapReduce >> mail # user >> what's the default reducer number?


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Jason Yang 2012-09-11, 11:23
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Re: what's the default reducer number?
Hi Lin

The default value for number of reducers is 1

<name>mapred.reduce.tasks</name>
  <value>1</value>

It is not determined by data volume. You need to specify the number of
reducers for your mapreduce jobs as per your data volume.

Regards
Bejoy KS

On Tue, Sep 11, 2012 at 4:53 PM, Jason Yang <[EMAIL PROTECTED]>wrote:

> Hi, all
>
> I was wondering what's the default number of reducer if I don't set it in
> configuration?
>
> Will it change dynamically according to the output volume of Mapper?
>
> --
> YANG, Lin
>
>
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Jason Yang 2012-09-11, 11:36
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Bejoy Ks 2012-09-11, 11:43
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Jagat Singh 2012-09-11, 11:47
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Jason Yang 2012-09-11, 12:37
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