Specifying change accumulation options for remote site recovery

The options used for change accumulation and remote site recovery.

The ONLY keyword on the CA command
If you add the ONLY keyword as input to the CA command of the change accumulation utility, CICS® VR only consolidates log records from the portion of the log stream that is read for the VSAM spheres in the change accumulation group. You can periodically run change accumulation batch jobs with the ONLY keyword specified, to produce change accumulation data sets that can be sent to a remote recovery site. Change accumulation data sets produced in this way do not contain overlapping data, and so the amount of data sent to the remote recovery site is reduced.
The log stream parameter for the ONLY keyword on the CA command
The first time you run a change accumulation batch job for a change accumulation group with the ONLY keyword specified, you must also specify the name of the log stream that contains the log records to be consolidated. The log stream name must be specified as a parameter to the ONLY keyword.

CICS VR associates the specified log stream with the change accumulation group and stores this information. You do not need to specify the log stream name for any subsequent CA runs for the same change accumulation group, unless you need to change the log stream name that CICS VR has associated with the CA group.

The DWWCA DD statement in the JCL for the batch job
If the ONLY keyword is specified, you must also specify the name of the output change accumulation data set in the DWWCA DD statement of the change accumulation batch job JCL. The record format of the change accumulation data set must be VB. CICS VR uses the following default DCB values if they are not specified on the DD statement:
  • Record length: 32752
  • Block size: 32756
Note: When the ONLY keyword is specified, CICS VR does not dynamically create the output change accumulation date set. Create the data set prior to running the change accumulation job, or specify the DISP=NEW parameter in the DWWCA DD statement allocation.
The ALL keyword on the SPHERE command
Each VSAM sphere that you want to include in a change accumulation group, can be specified as input to the change accumulation utility using the NAME keyword of the SPHERE command. However, you can also have CICS VR consolidate all log records for all VSAM spheres found on a particular log stream, without having to enter the name of each sphere individually. Specify the ALL keyword on the SPHERE command as input to the change accumulation utility, to have CICS VR consolidate all log records found for all VSAM spheres on the portion of the log stream that is read by CICS VR.
Note: The ALL keyword can only be specified on the SPHERE command if the ONLY keyword is specified on the CA command.