Updating Techniques, SYNCPOINT, and Logging › Using CICS SYNCPOINT

Using CICS SYNCPOINT

This release has simplified the management of CICS resources using CICS SYNCPOINT implementation for user log type commands. For more details, see User Issued Log Commands.

Important! Take great care to distinguish between user issued log commands and log commands that are issued as a result of SYNCPOINT. Both can generate the same log command, but they may not function exactly the same. A user issued log command is when an application issues a CA Datacom/DB request with its command being a log command.

The following simplifications come with this release:

• Synchronization of all resources is assured.
• Assurance that all LOGxx commands that checkpoint data will participate in both the MVS LOGGER (or CICS JOURNAL FILE if z/VSE) and the LXX.
• SYNCPOINT optimization of DB logging commands is allowed.
• The original user log command is preserved on the CA Datacom/DB LXX file.

All updates for application issued SYNCPOINTs and task termination SYNCPOINTs are true for both CA Datacom CICS Services r11 and Version 14.0. There is no difference between r11 and Version 14.0 for user issued or CICS issued SYNCPOINTs.

When an application program issues a CICS SYNCPOINT, all held data resources but not necessary sets, are released. Released resources include all resources under exclusive control, and the release of threads making those resources available for batch jobs or other CICS tasks to hold and update. Once an application issues a CICS SYNCPOINT, the CA Datacom CICS Service participates in SYNCPOINT, and the task completes one unit of work (UOW). Coding a CICS SYNCPOINT commits all updates to all resources including VSAM, DL/I, BDAM, DB2, and CA Datacom/DB, or CICS SYNCPOINT ROLLBACK to back them all out.

Important! If you want SYNCPOINT ROLLBACK to back out the updates for a transaction, the parameter value DTB=YES must be specified in the appropriate TRANSACTION definition. If DTB=NO is specified, SYNCPOINT ROLLBACK is treated as a SYNCPOINT and all the updates are committed.

Whenever possible, use the CICS SYNCPOINT or CICS SYNCPOINT ROLLBACK command for committing updates instead of specifying the CA Datacom/DB commands such as COMIT, LOGCP, LOGTB, or ROLBK. Also, when modifying old legacy programs containing these commands, consider converting the LOG commands to SYNCPOINTs at that same time.

Note: CBS and SQL sets are beyond the scope of this document. Therefore they are not obligated to follow any of the rules stated in this manual concerning exclusive control and there may be cases where sets remain beyond a SYNCPOINT or task termination or log commands.