Recently been into working with OSGi modules built on top of Apache Felix using the Eclipse bndtools. This ain’t fun all the time, but it works. However, I am then and now using visualvm for profiling and monitoring issues. With OSGi, at least the VisualVM profiler doesn’t work out of the box but instead causes a lot of fun just like this: java.lang.NoClassDefFoundError: org/netbeans/lib/profiler/server/ProfilerRuntimeCPUFullInstr at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:410) at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582) Caused by: