Is your site in the process of installing, or planning to install, CICS TS 2.2 but you are still running CICS TS 1.3? Well, this version contains several enhancements that were delivered since your site originally installed CICS TS 1.3. If your site is planning to run a great deal of business on 1.3 for a while, or if you’re interested in the new features since 2.2 was originally announced, here are some changes that have been delivered via the service process.
Once a new version is released, any enhancements are delivered as program temporary fixes (PTFs). Customers can then utilize the new function via parameter changes or other specific actions that need to be taken. The talented folks on the CICS Change Team in Hursley, U.K., have produced many of these new functions since CICS TS 1.3 went general availability (GA), so this article will identify some of the new functions that may be relevant to your systems. Some new functions are in categories that most CICS customers use, while others are more specific to unique components.
COBOL LANGUAGE ENVIRONMENT
While it is not specific to CICS TS 1.3, customers have been struggling with implementing the new COBOL (Language Environment [LE], COBOL3, or whatever it’s called) since it appeared. Another step in the migration is the “LE enablement” of CICS, where all former versions of COBOL are removed and replaced with SCEERUN and SCEECICS libraries. Early implementations were traumatic, since the default LE options were delivered for a batch (job) environment, not CICS. Since an MVS systems programmer usually installed COBOL, customers had no idea what the optimum values might be for CICS. They entered the “LE Zone,” a dark and scary place that was difficult to exit without battle scars. IBM began feeling the pain from the numerous frantic calls to CICS Level 2, and responded with some excellent and informative sessions about LE at the IBM Technical conferences.
The CEE (LE options) shipped for CICS now contain the proper HEAP and STACK storage values to optimize storage utilization in CICS. Do you have these? What current LE options are loaded into your CICS regions? Now there is a way for you to find out, and of course, the function was shipped via the service process; however, you will have to install a few resources before you can use it. APAR PQ38838 delivers a new CICS transaction (CLER) that allows some LE run-time options to be modified, displayed, or printed in any region. The program, map, and transaction definitions can be created via the job documented in the description. If you use program “autoinstall,” then the programs and maps will be installed as they are used. The one exception is program CEL4RTO, which must be explicitly defined because it needs to have EXECKEY specified as CICS. The default model for program autoinstall is EXECKEY = USER; therefore, IBM recommends LE definitions be defined in a group. In reality, you could create a group with a CEL4RTO program and a CLER transaction. The rest of the definitions will autoinstall fine. The result will be a new transaction that you can use to view, and potentially change, the values. Figure 1 shows an example of a typical CLER display.
The values under “Choice” can be overtyped to dynamically change the value. Realize, however, that any changes will be undone when the region recycles. The normal approach would be to change the values in the COBOL installation component. The most common change is to ALL31—ON or OFF. IBM recommends that the value be set to ON, which removes the requirement to GETMAIN storage from TASK24 subpools if the program is AMODE31 RMODE/ANY. This not only saves storage but also CPU time consumed by the region to manage these storage areas. If you can run with ALL31 ON, do it. If you don’t know if it will adversely impact your CICS applications, dynamically change the value to ON and test. This feature is especially convenient, since you can now change the value in a single region without impacting other regions. Additional program function (PF) key options are on the bottom of that screen. PF5 displays “Current Settings” beyond those displayed in the first screen. PF5 will display values such as those shown in Figure 2.
These options cannot be changed by overtyping, but they provide insight into what values are currently loaded into this particular CICS region. Note that HEAP and STACK storage contain 4,096 and 4,080 values. This was not the case originally (in earlier releases), but has been changed to be more efficient. CICS needs 8-byte storage areas in the front and rear of many storage allocations, so if 4,080 is required, it fits nicely into a 4KB slot.