Brian,
I agree that Vino is related to the issue, but not sure whether or not it's the direct cause. If killing Vino doesn't resolve the issue, then I suspect your issue is multi-rooted. Initially I would suspect either:
- Sun Java JDK performance limitations
- VM Swapping
- Running out of TCP connections (test via netstat and /var/log/messages)
- Running out of Execute Threads (WebLogic only)
(Note: I included #4 because it's often an issue on a WebLogic server, since this thread group is used by all incoming web connections from Tomcat. I'm sure OAS has a similar thread group, but don't yet know how to adjust it.)
I'm not aware of a hard-coded limit with WMServlet, but suspect that the Java JDK may be at the root of your issues. OAS uses the Sun JDK which has numerous performance limitations, in comparison to JRockit, which WebLogic uses.
In addition, can you verify whether or not the system is running out of physical memory, causing swapping (use iostat and vmstat) again? With only 4GB for the web/app, I suspect this may be an issue. If your OTM Java heaps for Tomcat and OAS are 1GB to 1.5GB, I'd recommend at least 6GB on the server, to handle Apache, the 2 Java Heaps, additional Java runtime memory and the OS. I know you stated that this was checked, but I'd verify again -- as this is often an issue on systems with so little memory.
--Chris