What are these java themes starting with "pool"?

Question

I have a problem with a Tomcat server that cannot legally shut down. I took a thread dump after I issued the shutdown command and it looks something like this:

http://pastebin.com/7SW4wZN9

A thread that I consider to be a “suspect” that does not allow the virtual machine to be shut down is called pool-4-thread-1. The rest of them are either daemon threads or internal VM threads. When trying to find out what this thread is for, I noticed that there are other java programs that create threads with similar names (for example, JVisualVM creates such threads).

So I'm wondering if anyone else knows what this thread is and how it can be created.

Answer 1

These threads are probably created by the ExecutorService that you created in your code somewhere (directly or indirectly through the library) and should be disabled (for example, in the ServletContextListener).