FUNCTION REQUEST SHIPPING - IBM Mainframe

CICS function shipping enables CICS application programs to:

  • Access CICS files owned by other CICS systems by shipping file control requests.
  • Access DL/I databases managed by or accessible to other CICS systems by shipping requests for DL/I functions.
  • Transfer data to or from transient-data and temporary-storage queues in other CICS systems by shipping requests for transient-data and temporary-storage functions.
  • Initiate transactions in other CICS systems, or other non-CICS systems that implement SNA LU Type 6 protocols, such as IMS, by shipping interval control START requests.

Applications can be written without regard for the location of the requested resources; they simply use file control commands, temporary-storage commands, and other functions in the same way. Entries in the CICS resource definition tables allow the system programmer to specify that the named resource is not on the local (or requesting) system but on a remote (or owning) system. In CICB, the request is passed to a special transaction known as the mirror transaction. The mirror transaction recreates the original request, issues it on CICB, and returns the acquired data to CICA.

The CICS recovery and restart facilities enable resources in remote systems to be updated, and ensure that when the requesting application program reaches a synchronization point, any mirror transactions that are updating protected resources also take a synchronization point, so that changes to protected resources in remote and local systems are consistent. The CICS master terminal operator is notified of any failures in this process, so that suitable corrective action can be taken. This action can be taken manually or by user-written code.


All rights reserved © 2018 Wisdom IT Services India Pvt. Ltd DMCA.com Protection Status

IBM Mainframe Topics