When database access has not been properly terminated, RUNDOWN properly closes currently inactive databases, removes abandoned GT.M database semaphores, and releases any IPC resources used. Under normal operations, the last process to close a database file performs the RUNDOWN actions, and a MUPIP RUNDOWN is not required. If a database file is already properly rundown, a MUPIP RUNDOWN has no effect. If in doubt, it is always to safe to perform a rundown. FIS recommends the following method to shutdown a GT.M application or the system:

MUPIP RUNDOWN checks for version mismatch. If there is a mismatch, it skips the region and continues with the next region. This makes it easier for multiple (non-interacting) GT.M versions to co-exist on the same machine. Note that GT.M does not support concurrent access to the same database file by multiple versions of the software.

The format of the RUNDOWN command is:

RU[NDOWN] [-FILE file-name | -REGION region-list]

MUPIP RUNDOWN clears certain fields in a file that is already closed. This facilitates recovery from a system crash or other operational anomaly.

Use RUNDOWN after a system crash or after the last process accessing a database terminates abnormally. RUNDOWN ensures that open databases are properly closed and ready for subsequent use. RUNDOWN has no effect on any database that is actively being accessed at the time the RUNDOWN is issued.

To ensure database integrity, all system shutdown algorithms should include scripts that stop at GT.M processes and perform RUNDOWN on all database files.

The RUNDOWN command may include one of the following qualifiers:

-F[ile] 
-R[egion] 

If the RUNDOWN command does not specify either -File or -Region, it checks all the IPC resources (shared memory) on the system and if they are associated with a GT.M database, attempts to rundown that file.