I am using a GF version "Sun Java System Application Server 9.1 (build b58g-fcs)" under Windows 2003 Server.
Yesterday, our client launch a new webapplication and the GF is not being able to support the heavy load (thousands of users). Exactly every 7 minutes the server hangs with a 25%, no message in the error log, nothing. It just cease to attend clients and I must stop the domain and restart the domain.