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From Harsh J <qwertyman...@gmail.com>
Subject Re: About System.out.print() Reduce Function
Date Fri, 22 Oct 2010 16:10:34 GMT
It actually does work. See the task attempt log for that job in the
web browser for an easy solution. Or tail -f the appropriate log file.

URL for task log is something like --
http://site:50060/tasklog?taskid={{ attempt_id }}&all=true and is
navigable to, from the JT.

The stdout is also written to the tasktracker's log directory, under
$HADOOP_HOME/logs/userlogs/{{ attempt_id }}/stdout, which is what the
above url also serves, if am right.

Although yes, stdout from mappers or reducers will not appear in your
launcher/driver program's output (i.e. hadoop jar [...]).


On Fri, Oct 22, 2010 at 2:44 PM, Flavio Pace <flavio.pace@gmail.com> wrote:
>
> Hi,
>
> This is the first time that i use Map-Reduce with Hadoop.. I need to print some information
in Reduce function to se if my code it's correct , but when i run System.out.println() there
is not output in my log.
>
> Someone can explain how to print debug information from reduce function to my log stdout?
>
> thanks
>
> Flavio
>
>
>
>



-- 
Harsh J
www.harshj.com

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