I blogged about this one on my old blog-system, but since I’ve been too lazy to import everything I’ll add another entry here. 😉
JFluid is a low overhead profiler that can be plugged into your system while it is still running. That means that it should be easy to find those bugs that surfaces only after your appserver has been running for two weeks. You can just deploy the app normally having no extra profiler overhead, and jump in with JFluid whenever it becomes necessarry. Check out more about it here.
Oh, and it requires their special hacked JVM. It would be nice if it could be supported on standard JVMs too.