The Application Server periodically stops responding and requires a stopall/startall via opmnctl. Upon investigating I found FRM-93000 errors in the application.log file in $ORACLE_HOME/j2ee/OC4J_BI_Forms/application-deployments/forms90app/OC4J_BI_Forms_default_island_3/
FRM-93000 is generated by the Forms Listener servlet code when the servlet can no longer communicate with the Forms Runtime process. FRM-93000 is a generic error and indicates that there has been a problem with the Forms Runtime engine.
Dump files are being created by Oracle in $ORACLE_HOME/forms90/trace/. The next step is to turn these CORE files into a stack trace. These stack traces are very useful for Oracle Support to help solve the underlying issue. Obtain a Stack Trace from the CORE file by following Note:1812.1
Finally create an Oracle Support Request and upload the following data with the SR:
• stack trace
• version numbers of your App Server and Forms