I'm running Hadoop 0.20.2 on a cluster of servers running Ubuntu 10.4. Each server has 2 quad-core Nehalem CPUs for a total of 8 physical cores running as 16 virtual cores. Ubuntu's System Monitor displays 16 squiggly lines showing usage of the 16 virtual cores. We only seem to be making use of one of the 16 virtual cores on any slave node and even on the master node only one virtual core is significantly busy at a time. Is there a way to make better use of the cores? Presumably I could run Hadoop in a VM assigned to each virtual core but I would think there must be a more elegant solution.
Alan Ratner
