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Posted to common-user@hadoop.apache.org by Owen O'Malley <om...@apache.org> on 2008/11/01 00:06:57 UTC
Re: Mapper settings...
On Oct 31, 2008, at 3:15 PM, Bhupesh Bansal wrote:
> Why do we need these setters in JobConf ??
>
> jobConf.setMapOutputKeyClass(String.class);
>
> jobConf.setMapOutputValueClass(LongWritable.class);
Just historical. The Mapper and Reducer interfaces didn't use to be
generic. (Hadoop used to run on Java 1.4 too...)
It would be nice to remove the need to call them. There is an old bug
open to check for consistency HADOOP-1683. It would be even better to
make the setting of both the map and reduce output types optional if
they are specified by the template parameters.
-- Owen
Re: Mapper settings...
Posted by Bhupesh Bansal <bb...@linkedin.com>.
In that case.
I will try to put a patch for this if nobody else is working on it
Best
Bhupesh
On 10/31/08 4:06 PM, "Owen O'Malley" <om...@apache.org> wrote:
>
> On Oct 31, 2008, at 3:15 PM, Bhupesh Bansal wrote:
>
>> Why do we need these setters in JobConf ??
>>
>> jobConf.setMapOutputKeyClass(String.class);
>>
>> jobConf.setMapOutputValueClass(LongWritable.class);
>
> Just historical. The Mapper and Reducer interfaces didn't use to be
> generic. (Hadoop used to run on Java 1.4 too...)
>
> It would be nice to remove the need to call them. There is an old bug
> open to check for consistency HADOOP-1683. It would be even better to
> make the setting of both the map and reduce output types optional if
> they are specified by the template parameters.
>
> -- Owen