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HDFS, mail # user - Is there any way to set Reducer to output to multi-places?


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Re: Is there any way to set Reducer to output to multi-places?
Binglin Chang 2013-09-02, 09:37
MultipleOutputFormat allows you to write multiple files in one reducer, but
can't write output to HDFS and Database concurrently, but I is a good
example to show how you can write a customized OutputFormat to achieve this.
Please note that for fault tolerance, a reducer may run multiple times,
this may generate redundant data, hadoop handles files using
FileOutputCommitter, you need to handle database case by yourself(e.g.
insert record only if record doesn't exists).
On Mon, Sep 2, 2013 at 5:11 PM, Rahul Bhattacharjee <[EMAIL PROTECTED]
> wrote:

> This might help
>
>
> http://hadoop.apache.org/docs/current/api/org/apache/hadoop/mapred/lib/MultipleOutputFormat.html
>
> Thanks,
> Rahul
>
>
> On Mon, Sep 2, 2013 at 2:38 PM, Francis.Hu <[EMAIL PROTECTED]>wrote:
>
>>  hi, All****
>>
>> ** **
>>
>> Is there any way to set Reducer to output to multi-places ?  For example:
>> a reducer's result can be output to HDFS and Database concurrently.****
>>
>> ** **
>>
>> Thanks,****
>>
>> Francis.Hu****
>>
>
>