Re: Working of combiner in hadoop

[Chris Mawata <ch...@gmail.com>]

The key/value pairs are processes by the mapper independently of each
other. The combiner logic deals with all the outputs from multiple
key/value pairs do that logic can not be in the map method.
 On Jul 4, 2014 1:29 AM, "Chhaya Vishwakarma" <
Chhaya.Vishwakarma@lntinfotech.com> wrote:

>  Hi,
>
>
>
> If have two map tasks running on one node , i have written combiner class
> also.
>
> Will combiner be called once for each map task or just once for both the
> map tasks
>
>
>
> Can i write a logic inside map which will work as combiner ? if yes will
> there be any side effect?
>
>
>
> Regards,
>
> Chhaya Vishwakarma
>
>
>
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