Defining a CICS VR XCF group

In a sysplex environment an instance of the CICS® VR server address space must be installed and running on particular systems.

Each system that:
  • Runs batch jobs that start CICS VR VSAM batch logging.
  • Notifies CICS VR about backups created for VSAM spheres.
  • Notifies CICS VR about CICS TS backout failures.

Only one instance of CICS VR can be active for each system.

Various tasks performed by the CICS VR server address space update the contents of the CICS VR Recovery Control Data Sets (RCDSs) allocated to the CICS VR server. The information in the RCDSs is then read by CICS VR during recovery job construction and processing. Therefore, to ensure data integrity of the RCDSs it might be desirable to logically group the CICS VR instances.

For example, consider the following scenario:
  • The CICS VR server address space is installed on 2 systems in a sysplex environment.
  • Both systems run batch jobs that start CICS VR VSAM batch logging for common VSAM spheres.

In this scenario, if a common VSAM sphere becomes corrupted, the updates made by batch jobs ran on both systems need to be recovered. Therefore, the same RCDSs must be allocated to both of the CICS VR instances in the sysplex. To enforce usage of the same RCDSs, CICS VR contains the CICSVR_GRPNAME_SUFFIX() parameter.

CICS VR allows you to logically group CICS VR instances into cross-system coupling facility (XCF) groups by specifying the following parameter in the active IGDSMSxx member:
CICSVR_GRPNAME_SUFFIX(suffix)
Where suffix specifies the CICS VR XCF group name suffix. The suffix can be 1 - 4 characters in length, and can be alphanumeric, A-Z, 0-9, and national ($, @, and #). PROD is the default value.

CICS VR ensures that all systems defined with the same CICS VR XCF group name suffix use the same set of RCDSs. Therefore, all CICS VR instances that either run batch jobs or notify CICS VR of backups created for common VSAM spheres must use the same CICS VR XCF group name.

When grouping CICS VR instances into XCF groups, the following notes must be considered:
  • IBM® recommends that all CICS VR instances that are part of the same CICS VR XCF group use common CICS VR load module libraries, SDWWLOAD and SDWWLPA. This ensures that all CICS VR instances in a CICS VR XCF group use the same level of CICS VR.

    Because CICS VR XCF groups operate independently of each other, CICS VR instances defined to a different CICS VR XCF group can use a different level of CICS VR.

  • Issuing a SETSMS command to change a CICS VR parameter only changes the specified parameter on the system that processes the request. The ROUTE command must be used to route the SETSMS command to all relevant systems. Also, some values changed by the SETSMS command only take effect when the system is restarted. Therefore, when updating a CICS VR parameter on all systems in a CICS VR XCF group, you must terminate and restart all active CICS VR servers after issuing the SETSMS command.
  • All CICS VR instances that perform batch logging or register backups for common VSAM spheres must be grouped into the same CICS VR XCF group.
  • All CICS VR instances in a CICS VR XCF group must have access to the same RCDSs. CICS VR ensures all instances in a CICS VR XCF group use the same RCDSs.