What range you gave it for mapred.task.profile.maps? And you sure your mapper will invoke the methods you expect in the traces?
Yong

Date: Wed, 6 Feb 2013 23:50:08 +0200
Subject: Profiling the Mapper using hprof on Hadoop 0.20.205
From: [EMAIL PROTECTED]
To: [EMAIL PROTECTED]

Hi,I wish to profile my mapper, so I've set the properties mapred.task.profile and mapred.task.profile.maps in mapred-site.xml.
At the end of the job I'm getting a profile.out file, however I think it's not the profile of the mapper... none of the methods I use in the mapper appear on any of the traces. Am I doing something wrong?
I'm using a small cluster with 4 machines.
Thanks,Yaron