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List:       hadoop-user
Subject:    Re: map(K1 key, V1 value, OutputCollector<K2, V2> output, Reporter
From:       steven zhuang <zhuangxin8448 () gmail ! com>
Date:       2010-01-30 11:58:56
Message-ID: a549c83b1001300358k55775ca9x25396e47e862757a () mail ! gmail ! com
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thanks you guys  :D


On Sat, Jan 30, 2010 at 2:16 AM, Jim Twensky <jim.twensky@gmail.com> wrote:

> Steven,
>
> I recently had the same issues, and I found this blog post very
> helpful on migrating from 0.19 to 0.20.2
>
> http://sonerbalkir.blogspot.com/2010/01/new-hadoop-api-020x.html
>
> You can download the sample code at the end, which contains a Hadoop
> word count program written using the new API.
>
> Hope this helps.
>
> -Jim
>
> On Thu, Jan 28, 2010 at 9:43 AM, Edward Capriolo <edlinuxguru@gmail.com>
> wrote:
> > 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/
> >
>



-- 
       best wishes.
                            steven


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