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From Jason Yang <lin.yang.ja...@gmail.com>
Subject Re: what's the default reducer number?
Date Tue, 11 Sep 2012 12:37:52 GMT
All right, I got it.

Thank you very much~

2012/9/11 Jagat Singh <jagatsingh@gmail.com>

> Just to add the name is depreciated in new Hadoop
> Try to find
> mapreduce.job.reduces
>
>
>
>
> On Tue, Sep 11, 2012 at 9:43 PM, Bejoy Ks <bejoy.hadoop@gmail.com> wrote:
>
>> 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
>>>
>>>
>>
>


-- 
YANG, Lin

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