While desperately trying out anything to unravel my load test glitches I came across TDA, a thread dump analysis tool for Java. Somehow I don't feel I am following its output. For instance, shouldn't there have been one thread in state RUNNABLE in the case where there is a monitor instance on which 8 threads are BLOCKED ? Some thread has had to gain that monitor's lock in order to put other 8 threads in BLOCKED state, is it ?
Second thing - about TDA terminology - there is the category "Threads sleeping on monitors (675 threads sleeping)" and the one called "Thread locking monitors (806 threads locking)". Both these categories contain threads which are either WAITING, BLOCKED or TIMED_WAITING. The only difference I can tell is that the latter category also contains threads in RUNNABLE state. Any other differences between them ? What I don't get is the syntagm "sleeping on monitors".
Thanks!