Managing CICS shutdown

You can initiate a normal or immediate shutdown of CICS®. In a normal shutdown, CICS performs a controlled sequence of operations that leave the system in a well-defined state; existing tasks are allowed to finish. In an immediate shutdown, CICS remains in overall control, but it does a minimum amount of processing so the system can terminate rapidly; existing tasks are not allowed to finish, and could abend.

For an overview of the types of CICS shutdown and to learn about what happens during CICS shutdown, see The types of CICS shutdown.

Before you begin

Before CICS shutdown, you can initiate a system cool-down to gradually stop flow of work into the region. To do so, you must set the WLMHEALTH system initialization parameter to activate the z/OS® Workload Manager Health service in the CICS region. To initiate a system cool-down, you can issue a SET WLMHEALTH OPENSTATUS(CLOSE) command or use CICS Explorer®. For more information, see CICS warm-up and cool-down, facilitated by z/OS Workload Manager health service.

About this task

To initiate a normal shutdown, you can use the CEMT PERFORM SHUTDOWN transaction or issue the EXEC CICS PERFORM SHUTDOWN command.

To initiate an immediate shutdown, you can use the CEMT PERFORM SHUTDOWN IMMEDIATE transaction or issue the EXEC CICS PERFORM SHUTDOWN IMMEDIATE command.

6.2 and later You can use these commands on CMAS and MAS regions. For a CMAS, CICS shuts down the CMAS as part of the shutdown process. For a MAS, CICS stops the MAS agent code as part of the shutdown process.

You can use these commands to shut down the CICSPlex® SM Web User Interface (WUI) server, provided that the WUI server is started with the CPSMCONN=WUI system initialization parameter. If the WUI server is not started with CPSMCONN=WUI, you must use COVC to shut it down. For more information, see Starting and stopping the CICSPlex SM WUI server.

Note: You can specify a CICS shutdown assist transaction to run at the beginning of a normal or an immediate shutdown, to shut down CICS in a controlled manner. This helps to solve two problems that might arise during CICS shutdown:
  • On a normal shutdown, CICS waits for all running tasks to finish before entering the second stage of shutdown. Long-running or conversational transactions can cause an unacceptable delay, or can require operator intervention.
  • On an immediate shutdown, CICS does not allow running tasks to finish; and backout is not performed until emergency restart. This can cause an unacceptable number of units of work to be shunted, with a consequent retention of locks.
You can specify the name of the shutdown assist transaction to be started during CICS shutdown processing in either of the following ways:
  • The SDTRAN system initialization parameter.
  • The SDTRAN (or NOSDTRAN) option on PERFORM SHUTDOWN. Values on the options override those on the SDTRAN system initialization parameter.

The default shutdown assist transaction is CESD, which invokes the CICS-supplied shutdown assist program, DFHCESD. For details of DFHCESD, see Shutdown assist program (DFHCESD). You can use the supplied program “as-is”, or as a sample on which to base your own shutdown transaction; see Your custom CICS shutdown assist program. See also Security for CICS shutdown.

The following topics give you instructions on how to shut down CICS by using the CEMT transaction.