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From yypvsxf19870706 <yypvsxf19870...@gmail.com>
Subject Re: Uber Job!
Date Mon, 06 May 2013 15:25:52 GMT
Hi

    Suppose that your input file are 10 with total size 64mb , I think you will get the 10
maps.

    By the ways,the uber mode is only for yarn . Suppose you have actually 1 map ,yarn will
at least create two containers , one for app master and the other for the map , if uber mode
is enabled with the yarn , yarn will only create 1 container for both app master and the map.

    

发自我的 iPhone

在 2013-5-6,22:45,Rahul Bhattacharjee <rahul.rec.dgp@gmail.com> 写道:

> Hi,
> 
> I was going through the definition of Uber Job of Hadoop.
> 
> A job is considered uber when it has 10 or less maps , one reducer and the complete data
is less than one dfs block size.
> 
> I have some doubts here-
> 
> Splits are created as per the dfs block size.Creating 10 mappers are possible from one
block of data by some settings change (changing the max split size). But trying to understand
, why would some job need to run around 10 maps for 64 MB of data.
> One thing may be that the job is immensely CUP intensive. Will it be a correct assumption?
or is there is any other reason for this.
> 
> Thanks,
> Rahul
> 
> 

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