- DBCDSCN is invoked by PLTSD during normal CICS termination.
- The DSCN command, with IMM (immediate) set to N, is issued by an authorized CICS terminal operator.
The following message is issued to the terminal from which the shutdown is invoked:
DCI0150: DBCCICS INTERFACE IS SHUTTING DOWN
The following stages occur during an orderly shutdown:
- Currently active CICS transactions accessing the database are allowed to run to completion.Shutdown proceeds once resources owned by these transactions are released, either:
- explicitly by application request, or
- implicitly by transaction or conversation termination.
If these transactions already have a session logged on at the time that interface shutdown is initiated, the transactions can do any of the following things:
- issue new requests,
- logon new sessions, or
- perform other actions.
- CLIv2 or Preprocessor2 resources owned by terminals that are involved in a pseudo-conversation but which do not have a CICS transaction active are released.
The sessions are logged off and the memory is released.
- It is not possible to release CLIv1 or Preprocessor1 resources owned by idle terminals within a pseudo-conversation because of differences in CLIv1 and Preprocessor 1 implementation.
Thus, interface shutdown will not complete until these resources are explicitly released by a transaction executing from the terminal or implicitly by termination of the pseudo-conversation.
DLGF can be used to log off the sessions but it will not release the resources.
- The 2PC (two-phase commit) connections are stopped after all resources are released.
- The task-related user exit is disabled for task start.
Any transaction that attempts to use the CICS Interface following an orderly shutdown is rejected with a non-zero return code, indicating that the interface is inactive.