hadoop-mapreduce-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Ed Mazur <ma...@cs.umass.edu>
Subject Re: Outputs to stdout and stderr not visible
Date Tue, 08 Dec 2009 18:45:05 GMT
Not sure why the stdout/stderr files in $HADOOP_LOG_DIR/userlogs/xxx
would be empty, but an alternative that I use is the log4j framework
used by Hadoop. You can instantiate it like this:

private static final Log LOG = LogFactory.getLog(YourClass.class);

And then use it like this:


If you use this in your map/reduce class, the messages will be in the
logs of individual tasks.


On Tue, Dec 8, 2009 at 7:14 AM, Kunal Gupta <kunal@techlead-india.com> wrote:
> I am outputting a message to stdout and stderr from inside my MAP
> function.
> but the stdout and stderr files in log folder are empty. I tried looking
> these logfiles from the web UI as well. They are empty only.
> Why are these messages not getting printed?
> Alternately, where can i print messages for debugging my MR
> application..?

View raw message