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From Edward Capriolo <edlinuxg...@gmail.com>
Subject Re: map(K1 key, V1 value, OutputCollector<K2, V2> output, Reporter reporter) deprecated in 0.20.2?
Date Thu, 28 Jan 2010 15:43:00 GMT
On Thu, Jan 28, 2010 at 8:14 AM, steven zhuang <zhuangxin8448@gmail.com> wrote:
> hello, all,
>                As a newbie, I have been used to the (k1,v1,k2,v2) format
> parameter list for map and reduce methods in mapper and reducer(as is
> written in many books), but after several failures, I found in 0.20+, if we
> extends from base class org.apache.hadoop.mapreduce.Mapper, the map should
> be something like this:
>
>         void map(KEYIN key, VALUEIN value, Context context) throws
> IOException, InterruptedException
>               A little confusing to me.
>               My question is why the old fashion map interface deprecated?
> thanks!
>
>
> --
>       best wishes.
>                            steven
>

Steven,

The old map/reduce api is still available. org.apache.hadoop.mapred

>               My question is why the old fashion map interface deprecated?

Cause hadoop is like a freight train, either hop on or get out of the way ! :)
Just kidding,

Great presentation about how to update code:
http://www.slideshare.net/sh1mmer/upgrading-to-the-new-map-reduce-api

Some information on the 'why'
http://www.cloudera.com/blog/2009/05/07/what%E2%80%99s-new-in-hadoop-core-020/

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