Shutdown assist program (DFHCESD)

You can use the SDTRAN system initialization parameter, or the SDTRAN option of the PERFORM SHUTDOWN command, to specify the name of the shutdown assist transaction to be started during CICS® shutdown processing. The default transaction is CESD, which invokes the CICS-supplied shutdown assist program, DFHCESD. You can use the supplied program “as is”, or as a sample on which to base your own shutdown transaction.

Unless SDTRAN=NO was specified at system initialization, or NOSDTRAN on the PERFORM SHUTDOWN command, the shutdown assist transaction is started automatically at the beginning of a normal or immediate shutdown. It runs under the user ID authority of the issuer of the shutdown command.

Monitoring statistics are lost if an immediate shutdown is implemented. This is a result of the shutdown, and any data in the monitoring buffer is lost.

If the program named by the shutdown transaction cannot be loaded, CICS waits indefinitely for all user tasks to complete, which might cause shutdown to hang. This happens on an immediate, as well as on a normal, shutdown.

You can use the shutdown assist transaction to help solve two of the problems that can arise when shutting down CICS:

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.