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From Max Heimel <mhei...@googlemail.com>
Subject Why doesnt my mapper speak to me :(
Date Sat, 14 Nov 2009 12:03:42 GMT
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

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?


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