If I use the partitioner, I must be able to tell map reduce to not
execute values from a certain reduce tasks.
The method |public int getPartition(K key, V value, int numReduceTasks)|
must always return a partition. I can’t return -1. Thus, I don’ t know
how to tell Mapreduce to not execute data from a partition. Any suggestion?
———— Forwarded Message ————
Subject: Re: Prune out data to a specific reduce task
Date: Thu, 12 Mar 2015 12:40:04 -0400
From: Fei Hu [email protected] <http://mailto:[email protected]>
Reply-To: [email protected]
To: [email protected]
Maybe you could use Partitioner.class to solve your problem.
On Mar 11, 2015, at 6:28 AM, xeonmailinglist-gmail
<[email protected] <mailto:[email protected]>> wrote:
Hi,
I have this job that has 3 map tasks and 2 reduce tasks. But, I want
to excludes data that will go to the reduce task 2. This means that,
only reducer 1 will produce data, and the other one will be empty, or
even it doesn't execute.
How can I do this in MapReduce?
<ExampleJobExecution.png>
Thanks,
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