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From Hemanth Yamijala <yhema...@thoughtworks.com>
Subject Re: mappers-node relationship
Date Sat, 26 Jan 2013 07:21:31 GMT
This may beof some use, about how maps are decided:



On Friday, January 25, 2013, jamal sasha wrote:

> Hi.
>   A very very lame question.
> Does numbers of mapper depends on the number of nodes I have?
> How I imagine map-reduce is this.
> For example in word count example
> I have bunch of slave nodes.
> The documents are distributed across these slave nodes.
> Now depending on how big the data is, it will spread across the slave
> nodes.. and that is how my number of mappers are decided.
> I am sure, this is wrong understanding. As in pseudo-distributed node, i
> can see multiple mappers.
> So question is.. how does a single node machine runs multiple mappers? is
> it run in parallel or sequentially??
> Any resources to learn these
> Thanks

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