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From Bejoy Ks <bejoy.had...@gmail.com>
Subject Re: what's the default reducer number?
Date Tue, 11 Sep 2012 11:43:56 GMT
Hi Lin

The default values for all the properties are in
core-default.xml
hdfs-default.xml and
mapred-default.xml


Regards
Bejoy KS


On Tue, Sep 11, 2012 at 5:06 PM, Jason Yang <lin.yang.jason@gmail.com>wrote:

> Hi, Bejoy
>
> Thanks for you reply.
>
> where could I find the default value of mapred.reduce.tasks ? I have
> checked the core-site.xml, hdfs-site.xml and mapred-site.xml, but I haven't
> found it.
>
>
> 2012/9/11 Bejoy Ks <bejoy.hadoop@gmail.com>
>
>> 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 <lin.yang.jason@gmail.com>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
>>>
>>>
>>
>
>
> --
> YANG, Lin
>
>

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