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From sudhakara st <sudhakara...@gmail.com>
Subject Re: the default value for param "mapreduce.reduce.shuffle.input.buffer.percent"
Date Fri, 16 May 2014 17:45:30 GMT
"mapreduce.reduce.shuffle.input.buffer.percent"  paramenter value is going
go sets by reading the mapred-site.xml, if you not specified value in
mapred-site.xml it reads value from mapred-default.xml. Its value in
mapred-default.xml is 0.7. So default value is 0.7. For various reason
mapreduce.reduce.shuffle.input.buffer.percent is null then it will reads
hard coded value from the fuction MergeManagerImpl.java as 0.9. I think
this case never arises, MR always set parameters values by reading
mapred-default.xml.

Regards,
Sudhakara


On Fri, May 16, 2014 at 8:45 AM, wzc <wzc1989@gmail.com> wrote:

> Hi,
>    I find the defualt value for
> "mapreduce.reduce.shuffle.input.buffer.percent" is 0.7
> in mapred-default.xml but  0.9 in MergeManagerImpl.java. I wonder which
> default value should I choose ? I think 0.9 maybe too high ?
> Any help is appreciated.
>
> Thanks.
>
>


-- 

Regards,
...sudhakara

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