hadoop-mapreduce-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Joey Echeverria <j...@cloudera.com>
Subject Re: num of reducer
Date Thu, 16 Feb 2012 13:26:53 GMT
Hi Tamil,

I'd recommend upgrading to a newer release as 0.19.2 is very old. As for
your question, most input formats should set the number mappers correctly.
What input format are you using? Where did you see the number of tasks it
assigned to the job?


On Thu, Feb 16, 2012 at 1:40 AM, Thamizhannal Paramasivam <
thamizhannal.p@gmail.com> wrote:

> Hi All,
> I am using hadoop-0.19.2 and running a Mapper only Job on cluster. It's
> input path has >1000 files of 100-200MB. Since, it is Mapper only job, I
> gave number Of reducer=0. So, it is using 2 mapper to run all the input
> files. If we did not state the number of mapper, would n't it pick the 1
> mapper per input file? Or Does the default won't it pick a fair num of
> mapper according to number input file?
> Thanks,
> tamil

Joseph Echeverria
Cloudera, Inc.

View raw message