IBM SC34-7012-01 manual CICS warm restart, Rebuilding the CICS state after a normal shutdown

Chapter 5. CICS warm restart

This section describes the CICS startup processing specific to a warm restart.

If you specify START=AUTO, which is the recommended method, CICS determines which type of start to perform using information retrieved from the recovery manager's control record in the global catalog. If the type-of-restart indicator in the control record indicates “warm start possible”, CICS performs a warm restart.

You should not attempt to compress a library after a warm start, without subsequently performing a CEMT SET PROGRAM(PRGMID) NEWCOPY for each program in the library. This is because on a warm start, CICS obtains the directory information for all programs which were installed on the previous execution. Compressing a library could alter its contents and subsequently invalidate the directory information known to CICS.

See Chapter 6, “CICS emergency restart,” on page 61 for the restart processing performed if the type-of-restart indicates “emergency restart needed”.

Rebuilding the CICS state after a normal shutdown

During a warm restart, CICS initializes using information from the catalogs and system log to restore the region to its state at the previous normal shutdown.

Note: CICS needs both the catalogs and the system log from the previous run of CICS to perform a warm restart—the catalogs alone are not sufficient. If you run CICS with the system log defined as TYPE(DUMMY), CICS appears to shut down normally, but only the global catalog portion of the warm keypoint is written. Therefore, without the warm keypoint information from the system log, CICS cannot perform a warm restart. CICS startup fails unless you specify an initial start with START=INITIAL.

Recovering their own state is the responsibility of the individual resource managers (such as file control) and the CICS domains. This topic discusses the process of rebuilding their state from the catalogs and system log, in terms of the following resources:

vFiles

vTemporary storage queues

vTransient data queues

vTransactions

vLIBRARY resources

vPrograms, including mapsets and partitionsets

vStart requests

vMonitoring and statistics

vJournals and journal models

vTerminal control resources

vDistributed transaction resources

vURIMAP definitions and virtual hosts

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