Please try Hadoop 0.13.0. I don't know whether it will address your concerns, but it should be faster and is much closer to what developers are currently working on.
ok. It would also be good to see how DFS upgrade go between versions. (looks like it got released today. cool.)
For such a small cluster you'd probably be better running the jobtracker and namenode on the same node and gain another slave.
When namenode and jobtracker were running on the same machine, I notice failures due to losing contact with jobtracker. This is why I split the machines. With regard to the performance details, it is really independent of how many slaves I have. The test is mainly trying to see how close Hadoop compares to single node or scp, and what are the tuning parameters to make things run faster. Any suggestions on java profiling tools? bwolen
