Just a word of warning. I was playing around with VisualVM. I connected it to a running instance of JBossAS 5.0.0.CR1 that was not doing anything. Suddenly, the app server became active. The CPU usage was still relatively low, but every 20 seconds I was getting a garbage collection.

Apparently, just connecting VisualVM to a Java app causes objects and garbage to be created.

I checked JConsole and it does not exhibit this behavior.

This behavior makes VisualVM a poor choice for monitor Java applications in production.

By the way, I was using the VisualVM from JDK 6u7, and I ran AS 5.0.0.CR1 on the same version.