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From madhu phatak <phatak....@gmail.com>
Subject Re: IdentityReducer is called instead of my own
Date Thu, 03 Feb 2011 10:47:21 GMT
Read Oreilly.Hadoop.The.Definitive.Guide book. It points out the changes in
new and old api.

On Thu, Feb 3, 2011 at 3:53 AM, Christian Kunz <ckunz@yahoo-inc.com> wrote:

> I don't know of a transition guide, but I found a tutorial based on the new
> api:
>
> http://hadoop.apache.org/mapreduce/docs/current/mapred_tutorial.html
>
> I did not use it, but it might be useful.
>
> BTW, you could use the
>
> @Override
>
> annotation when overriding any method to let the compiler detect issues
> like yours.
>
> -Christian
>
> On Feb 2, 2011, at 2:06 PM, Marco Didonna wrote:
>
> > On 02/02/2011 10:23 PM, Christian Kunz wrote:
> >> Without seeing the source code of the reduce method of  the
> InvIndexReduce class
> >> my best guess would be that the signature is incorrect. I saw this
> happen when migrating from old to new api:
> >>
> >> protected void reduce(KEYIN key, Iterable<VALUEIN> values, Context
> context)
> >>
> >> (Iterable, not Iterator as in the old api)
> >>
> >> -Christian
> >>
> >
> > My God you're right...are you a sensitive or what :) :)? I am pretty new
> > to Hadoop and I have studied the Tom White's book which is based on the
> > old api (too bad)...I find quite difficult the migration to the new
> > api...Is there a transition guide?
> >
> > Thank you very very much...I was going to call an exorcist since there
> > was no warning, no error whatsoever...
> >
> > Marco
> >
>
>

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