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From Nan Zhu <zhunans...@gmail.com>
Subject Re: How can I limit reducers to one-per-node?
Date Sat, 09 Feb 2013 03:59:04 GMT
I think set tasktracker.reduce.tasks.maximum  to be 1 may meet your requirement


Nan Zhu
School of Computer Science,
McGill University

On Friday, 8 February, 2013 at 10:54 PM, David Parks wrote:

> I have a cluster of boxes with 3 reducers per node. I want to limit a particular job
to only run 1 reducer per node.
> This job is network IO bound, gathering images from a set of webservers.
> My job has certain parameters set to meet “web politeness” standards (e.g. limit
connects and connection frequency).
> If this job runs from multiple reducers on the same node, those per-host limits will
be violated.  Also, this is a shared environment and I don’t want long running network bound
jobs uselessly taking up all reduce slots.

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