IBM SC34-7012-01 manual Second quiesce stage, Third quiesce stage

vThe DFHCESD program started by the CICS-supplied transaction, CESD, attempts to purge and back out long-running tasks using increasingly stronger methods (see “The shutdown assist transaction” on page 30).

vTasks that are automatically initiated are run—if they start before the second quiesce stage.

vAny programs listed in the first part of the shutdown program list table (PLT) are run sequentially. (The shutdown PLT suffix is specified in the PLTSD system initialization parameter, which can be overridden by the PLT option of the CEMT or EXEC CICS PERFORM SHUTDOWN command.)

vA new task started as a result of terminal input is allowed to start only if its transaction code is listed in the current transaction list table (XLT) or has been defined as SHUTDOWN(ENABLED) in the transaction resource definition. The XLT list of transactions restricts the tasks that can be started by terminals and allows the system to shut down in a controlled manner. The current XLT is the one specified by the XLT=xx system initialization parameter, which can be overridden by the XLT option of the CEMT or EXEC CICS PERFORM SHUTDOWN command.

Certain CICS-supplied transactions are, however, allowed to start whether their code is listed in the XLT or not. These transactions are CEMT, CESF, CLR1, CLR2, CLQ2, CLS1, CLS2, CSAC, CSTE, and CSNE.

vFinally, at the end of this stage and before the second stage of shutdown, CICS unbinds all the VTAM terminals and devices.

The first quiesce stage is complete when the last of the programs listed in the first part of the shutdown PLT has executed and all user tasks are complete. If the CICS-supplied shutdown transaction CESD is used, this stage does not wait indefinitely for all user tasks to complete.

Second quiesce stage

During the second quiesce stage of shutdown:

vTerminals are not active.

vNo new tasks are allowed to start.

vPrograms listed in the second part of the shutdown PLT (if any) run sequentially. These programs cannot communicate with terminals, or make any request that would cause a new task to start.

The second quiesce stage ends when the last of the programs listed in the PLT has completed executing.

Third quiesce stage

During the third quiesce stage of shutdown:

vCICS closes all files that are defined to CICS file control. However, CICS does not catalog the files as UNENABLED; they can then be opened implicitly by the first reference after a subsequent CICS restart.

Files that are eligible for BWO support have the BWO attributes in the ICF catalog set to indicate that BWO is not supported. This prevents BWO backups being taken in the subsequent batch window.

vAll extrapartition TD queues are closed.

vCICS writes statistics to the system management facility (SMF) data set.

vCICS recovery manager sets the type-of-restart indicator in its domain state record in the global catalog to “warm-start-possible”. If you specify START=AUTO when you next initialize the CICS region, CICS uses the status of

26CICS TS for z/OS 4.1: Recovery and Restart Guide