If you don't specify the number of Reducers, Hadoop will use the default -- 
which, unless you've changed it, is 1.

Regards

Ian.

On Aug 29, 2013, at 4:23 PM, Adeel Qureshi <[email protected]> wrote:

> I have implemented secondary sort in my MR job and for some reason if i dont 
> specify the number of reducers it uses 1 which doesnt seems right because im 
> working with 800M+ records and one reducer slows things down significantly. 
> Is this some kind of limitation with the secondary sort that it has to use a 
> single reducer .. that kind of would defeat the purpose of having a scalable 
> solution such as secondary sort. I would appreciate any help.
> 
> Thanks
> Adeel


---
Ian Wrigley
Sr. Curriculum Manager
Cloudera, Inc
Cell: (323) 819 4075

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