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MapReduce >> mail # user >> Re: how to execute different tasks on data nodes(simultaneously in hadoop).


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Re: how to execute different tasks on data nodes(simultaneously in hadoop).
Hi,

Assuming you have to compute these value for every RGB pixel.
Why couldn't you compute all these values at the same time on the same node?

Hadoop let you distribute your computation but it doesn't mean each node
has to compute only a part of the equations.
Each node can compute all equations but for a 'small' part of the data.
That's Hadoop strategy. That way, sequential read and data locality will
improve your performances.

Regards

Bertrand

On Mon, Sep 3, 2012 at 6:35 PM, mallik arjun <[EMAIL PROTECTED]> wrote:

> [image: Inline image 1]
>
> On Mon, Sep 3, 2012 at 10:01 PM, Bertrand Dechoux <[EMAIL PROTECTED]>wrote:
>
>> You can check the value of "map.input.file" in order to apply a different
>> logic for each type of files (in the mapper).
>> More information about your problem/context would help the readers to
>> provide a more extensive reply.
>>
>> Regards
>>
>> Bertrand
>>
>> each data node has to process one equation of above simultaneously.
>
>
>> On Mon, Sep 3, 2012 at 6:25 PM, Michael Segel <[EMAIL PROTECTED]>wrote:
>>
>>> Not sure what you are trying to do...
>>>
>>> You want to pass through the entire data set on all nodes where each
>>> node runs a single filter?
>>>
>>> You're thinking is orthogonal to how Hadoop works.
>>>
>>> You would be better off letting each node work on a portion of the data
>>> which is local to that node running the entire filter set.
>>>
>>>
>>> On Sep 3, 2012, at 11:19 AM, mallik arjun <[EMAIL PROTECTED]>
>>> wrote:
>>>
>>> > genrally in hadoop map function will be exeucted by all the data nodes
>>> on the input data set ,against this how can i do the following.
>>> > i have some filter programs , and what i want to do is each data
>>> node(slave) has to execute one filter alogrithm  simultaneously, diffent
>>> from other data nodes executions.
>>> >
>>> > thanks in advance.
>>> >
>>> >
>>>
>>>
>>
>>
>> --
>> Bertrand Dechoux
>>
>
>
--
Bertrand Dechoux