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From Marcos Pinto <marcos...@gmail.com>
Subject Re: Problem: when I run a pig's script I got one reduce task
Date Thu, 05 Aug 2010 14:28:22 GMT
Oh Man!!! Thanks, your tip comes in handy, =). I had tried to set some
properties but It hadnt worked out but now when I use PARALLEL clause it
works very well. thanks dude. Have nice day.

On Thu, Aug 5, 2010 at 10:38 AM, Gibbon, Robert, VF-Group <
Robert.Gibbon@vodafone.com> wrote:

> Use the PARALLEL clause of course!
> Increase the parallelism of a job by specifying the number of reduce
> tasks, n. The default value for n is 1 (one reduce task). Note the
> following:
>    * Parallel only affects the number of reduce tasks. Map parallelism
> is determined by the input file, one map for each HDFS block.
>    * If you don't specify parallel, you still get the same map
> parallelism but only one reduce task.
> For more information, see the Pig Cookbook.
> -----Original Message-----
> From: Marcos Pinto [mailto:marcoscba@gmail.com]
> Sent: Donnerstag, 5. August 2010 14:56
> To: general@hadoop.apache.org
> Subject: Problem: when I run a pig's script I got one reduce task
> Hi guys, how u doing?
> I am learning how to use hadoop and I got this problem:
> I set up a cluster with 5 nodes( 4 datanode n 1 namenode) and I used the
> same configuration for jobtracker n tasktracker.
> when I run a pig's script I get many map's( like 15) but just 1
> reduce!!!!!
> this kills all the parallel processing. For example.
> I have a file that has 1 GB and when I run the pig's script in a cluster
> It takes about 50 minutes to process. =(
> So I really appreciate if someone could help with any tip. Thanks for
> your time.

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