I have a fairly large application running under 3.2.7 that I'm trying to upgrade to 4.2.2.GA. The code upgrade was fairly trivial, and I've got the app running in test mode now. One part of this app creates a ThreadGroup to process a set of data files; the end of this processing is to insert data into an Oracle database using a no-tx-datasource. All the inserts are being completed successfully. But when I determine all worker threads are finished and attempt to destroy the ThreadGroup, I'm getting an IllegalThreadStateException. Upon doing a ThreadGroup.enumerate(), I'm finding a single thread with name IdleRemover. Why is this IdleRemover thread being inserted into my private ThreadGroup? I've spent a couple hours looking at old forum discussions, and I see that IdleRemover was present in 3.2.7. But the app running on that version didn't have this problem. So I'm guessing the implementation of IdleRemover has changed in 4.2.2. How do I fix this? Thanks. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4161384#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...