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Hadoop >> mail # user >> how to set diffent VM parameters for mappers and reducers?


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Re: how to set diffent VM parameters for mappers and reducers?
For 0.20.x, you can specify java opts for your tasks with:

mapred.child.java.opts for all tasks
mapred.map.child.java.opts (mapreduce.map.java.opts for 0.21+) for maps
mapred.reduce.child.java.opts (mapreduce.reduce.java.opts for 0.21+)
for reduces.

__Luke

On Tue, Oct 12, 2010 at 12:54 AM, Vitaliy Semochkin
<[EMAIL PROTECTED]> wrote:
> Steve,
>
> I'm working with hadoop - 0.20.2
> was trhis feature available in hadoop 0.20.2 or it is a new feature of 0.21?
>
> Regards,
> Vitaliy S
>
>
>
> 2010/10/11 Steve Loughran <[EMAIL PROTECTED]>:
>> On 11/10/10 11:13, Vitaliy Semochkin wrote:
>>> I guess we should create  a feature request )
>>
>> no, If it doesn't work it is a bug. Therefore you should
>>
>> -get the latest released version of the code, that is 0.21
>> -search for the string there, check they are both actually being used,
>> see what happens to them.
>> -file a bug report
>> -write some MR job which would verify that the settings are passed down
>> -attach it as a test case.
>>
>> Hadoop is a community project, which means if you want a feature fixed,
>> on your schedule, you get to fix it.
>>
>> It's going to be hard to test this in the normal LocalMRCluster tests,
>> as they all run in-JVM, but there is work going on in the -dev lists on
>> better testing; they could the tests
>>
>> -steve
>>
>