IBM SC34-7012-01 manual Final summary

If a disaster occurs at the primary site, your disaster recovery procedures should include recovery of VSAM data sets at the designated remote recovery site. You can then emergency restart the CICS regions at the remote site so that they can backout any uncommitted data. Special support is needed for RLS because record locks, which were protecting uncommitted data from being updated by other transactions at the primary site, are not present at the remote site. You invoke CICS RLS support for off-site recovery using the OFFSITE system initialization parameter.

The OFFSITE system initialization parameter protects all RLS data sets until all emergency restart recovery is complete. You can specify this OFFSITE system initialization parameter at run-time only—it cannot be specified and assembled in the SIT—and it is valid only when START=AUTO is specified. You specify OFFSITE=YES when restarting CICS regions at a remote site when recovery involves VSAM data sets opened in RLS mode.

When you specify OFFSITE=YES, file control performs RLS off-site recovery processing, under which file control does not allow any new RLS access during startup. With RLS recovery in operation during an emergency restart, CICS does not allow any data sets to be accessed in RLS mode until:

vCICS has completed all outstanding RLS recovery work.

vCICS file control has issued a message requesting a “GO” response from an operator when all CICS regions have completed RLS recovery processing.

vAn operator has replied to the message.

Operators should reply to the message only when all the CICS regions being restarted with OFFSITE=YES have issued the message, indicating that they have all completed their RLS recovery.

A CICS-supplied sample NetView EXEC, DFH$OFAR, is provided to automate the detection of, and reply to, the WTOR console messages. For more information, see the prolog in the source member of the CICSTS41.CICSSDFHSAMP. library.

Final summary

Your disaster recovery plan will be truly tested only at a very difficult time for your business—during a disaster. Careful planning and thorough testing may mean the difference between a temporary inconvenience and going out of business.

The goal of your disaster recovery plan is to get your CICS systems back online. The currency of the data and the time it takes to get back online is a function of which disaster recovery tier you use. Unless legal requirements for disaster recovery dictate the type of disaster recovery you must have, the choice of tiers is usually a business decision.

Making your disaster recovery work requires a good plan, up-to-date documentation, and regular testing.

240CICS TS for z/OS 4.1: Recovery and Restart Guide