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From "Ted Dunning" <ted.dunn...@gmail.com>
Subject Re: OK to remove conf.setCombinerClass(myReduce.class)?
Date Mon, 18 Aug 2008 20:57:06 GMT
This doesn't sound right.

There are two reasons.

First, the combiner is critical for good performance on word count

Secondly, having a combiner should not prevent having a different kind of
collector.  The combiner should just look like the reducer.

Why do you think that having the combiner is causing your problem?

On Mon, Aug 18, 2008 at 1:32 PM, Kunsheng Chen <hadoopchan@yahoo.com> wrote:

> Hello, everyone.
> I am doing  example  WordCount and have to remove
> conf.setCombinerClass(myReduce.class) in main method in order to have maper
> and reduce run with different types of output collector.
> I am not sure whether it cause the problem for the perfomance.  Please let
> me know if it does.   Any idea is appreciated.


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