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Date: Mon, 27 Aug 2012 19:11:21 +0200
From: Eduard Skaley <e.v.skaley@gmail.com>
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Subject: Controlling on which node a reducer will be executed
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Hi,

i have a question concerning the execution of reducers.
To use effectively the data locality of blocks in my use case i want to
control on which node a reducer will be executed.

In my scenario i have a chain of map-reduce jobs where each job will be
executed by exactly N reducers.
I want to achieve that for each job reducer 1 is executed on node 1,
reducer 2 on node 2 and so on.

Is it possible with a customization of the BlockPlacementPolicy in MRv2 ?
Or is there some other way, maybe some indirect ? Or is it impossible ?

Thanks for your help.
Eduard