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From Inifok Song <hadoop.ini...@gmail.com>
Subject Re: Difference between copyOutput() and fetchOutputs()
Date Fri, 28 Aug 2009 05:30:23 GMT
Oops! I'm so careless that haven't noticed it. This is really a rookie
question. Thanks for your answer.

2009/8/28 Jothi Padmanabhan <jothipn@yahoo-inc.com>

> Reduce Task creates a ReduceCopier object and invokes fetchOutput method on
> this object to start the fetch process.
>
> fetchOutputs internally launches several MapOutputCopier threads to do the
> fetching and each of these thread do the copyOutput.
>
> Jothi
>
>
> On 8/28/09 9:06 AM, "Inifok Song" <hadoop.inifok@gmail.com> wrote:
>
> > Hello all,
> >
> > In class ReduceTask, there are a lot of methods to deal with fetching
> > intermediate output. And I think copyOutput() and fetchOutputs() are the
> > most important. However, they are invoked by different methods. I wonder
> > know whether they deal with the same thing? What's the difference between
> > them?
> >
> > Thank you.
> >
> > Inifok
>
>

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