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Date: Sat, 14 Nov 2009 13:03:42 +0100
Message-ID: <5eb9b7ae0911140403g6f27f77fj83b9bc27e856ecf8@mail.gmail.com>
Subject: Why doesnt my mapper speak to me :(
From: Max Heimel <mheimel@googlemail.com>
To: mapreduce-user@hadoop.apache.org
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Hey all,

I am currenty trying to write a simple map job that dumps a file to
the hdfs. I see that hadoop creates 3 instances of my mapper class (I
expected 3, so this is fine :) but then things get a bit confusing for
me...

First the files don't show up in the file system, which is probably
due to some misconfiguration ;) So I tried to let the mapper print
some debug messages so I see where it actually fails. But: I just
don't seem to be able to get any debug messages out of my mapper.

I tried using printing to Sysout/Syseerr and
(org.apache.log4j.)Logger.getLogger(MyMapper.class), but there never
is any of my debug output in any of the logs created by hadoop: The
logged sysout/syserr for the mappers are just empty. The log4j log
file isn't even created :(

Any ideas what I am doing wrong here?

Thanks
Max