I am using JBoss 4.2.0, all conf, ClusterdSSOValve with cookiedomain, ajax4jsf, richfaces 3.3.0 GA and a4j:poll component in some jsp pages, the whole thing in a production environment that receives more than 400.000 tx per day.
We are experiencing an unexpected behaviour, where we login properly, hit some pages in one of the web apps. then go to another web app. where we have rich graphics in a jsp using a4j:poll component. This page works fine even for hours, refreshing data correctly, our session timeout is 30 minutes (default value), in each request fired by the a4j:poll component the session is accessed, but, after some hours (not always the same time) the whole sessions are destroyed and we can see it because we have implemented HttpSessionListener in each web app and the page freezes.
Don't know what is happening and this doesn't happens in our test environment, the difference we could see is the sustained overload.
Any more information that you need, just ask me about it.