what kind of command are u using to find out the CPU usage? could be "ps". in this case, quoting from ps man we have that <%CPU shows the cputime/realtime percentage. It will not add up to 100% unless you
are lucky. It is time used divided by the time the process has been running.> witch make sense. the percentange is not a snapshot of the CPU usage, it is <the time the CPU was used by the process since it was started>/<the time the process was started>
If your app is loaded at a constant level %CPU should increase. if after that the jboss does nothing, the %CPU should decrease but not immediately, in time.
I am using top to find the cpu usage and it staus at 94-95 % for hours after the last log line. I have always had to restart jboss once it gets in this situation.
Even when it is at this 95% cpu usage It still reponds to new client requests. The old clients simply hang.