Windows Considerations When Using MDBs

The oracle.mdb.fastUndeploy system property enables you to shutdown OC4J cleanly when you are running MDBs in a Windows environment or when the backend database is running on a Windows environment. Normally, when you use an MDB, it is blocked in a receive state waiting for incoming messages. However, if you shutdown OC4J while the MDB is in a wait state in a Windows environment, then the OC4J instance cannot be stopped and the applications are not undeployed since the MDB is blocked. However, you can modify the behavior of the MDB in this environment by setting the oracle.mdb.fastUndeploy system property. If you set this property to an integer, then when the MDB is not processing incoming messages and in a wait state, the OC4J container goes out to the database (requiring a database round-trip) and polls to see if the session is shut down. The integer denotes the number of seconds the system waits to poll the database. This can be expensive for performance. If you set this property to 60 (seconds), then every 60 seconds, OC4J is checking the database. If you do not set this property and you try to shutdown OC4J using CTRL-C, the OC4J process will hang for at least 2.5 hours.