Hello anonymous monk.
What you report here is not consistent with what I've seen. Thread::Pool looks like it depends on 5005threads, an old threading model that was deprecated with perl 5.8, I believe. Unfortunately, the Camel book was written for 5.6, so if you're basing your threading work on that, your code will be out of date. In fact, according to the Thread, the Thread module was removed from Perl in 5.10, so the module shouldn't even compile on your machine.
I don't know too much about threads, but I'm pretty sure you can find similar (if not better) facilities for your work using the new threads interface.
in reply to Thread::Pool shutdown dies after abort