I just ran into the same problem. It's really easy to reproduce in 6.0.0.Final:
- Configure an async-handler (uncomment the example), and set the handler-refs in the sub-handler section to point to FILE and CONSOLE.
- Configure the root-logger with a single handler-ref that points to the new ASYNC handler.
- Start JBoss AS
- Go to the admin-console... wait... wait... wait... wait... notice OOMEs and stuff in any logs that actually make it to the file.
I agree with Tomaz Cerar, async logging is a must-have for a production server. I'll try using an application-specific log4j.xml, but I can't find any examples of doing that with an EAR in JBoss AS 6.