Mainframe systems are the backbone of finance, health care, and many other industries, which is why the reliability of those systems is paramount. IBM Champion and SHARE Pittsburgh Best of the Best Session winner Ezriel Gross, principal solutions advisor at Rocket Software, says IPCS (Interactive Program Control System) puts the power of locating and solving CICS (Customer Information Control System) application software failures in the hands of the user.

CICS is used by customers to write and run applications for managing high-volume online transactions that are key to successful financial institutions, insurance companies, Fortune 500 companies, and government agencies. “What makes CICS stand out is that the applications running under it tend to provide sub-second response time while remaining secure and resilient,” Gross explains. “A rogue application can be dealt with individually, rather than involving all the other users of the system.” Because CICS allows for storage protection rules to be relaxed in certain locations within the product, he says this can lead to one application overwriting the storage area of another application. In some cases, this may be within the system itself, and is known as a storage violation. “The good news is CICS, in many cases, can detect this violation and produce a dump, allowing a customer to try to find the offending application program,” Gross says.

Without a tool like IPCS to review these dumps — and the knowledge of how to use it — Gross says users would have to seek help from IBM for each software failure they encounter. IPCS is a component of z/OS used for online problem management, interactive problem diagnosis, and debugging for ABEND dumps. In his SHARE Pittsburgh Best of the Best Session award winning presentation, “Intro to IPCS for CICS People,” he introduced the IPCS features that are the most relevant to solving CICS problems. Gross highlighted the basics of using IPCS for CICS dumps, which include:

• The minimum SDUMP options to take and format a CICS system dump successfully
• The commands, along with IBM-supplied and user-written routines, that provide specialized formatting of CICS control blocks and structures
• An overview of the most useful IPCS subcommands for a CICS dump, supported by real-life examples

The Power of IPCS Keyword Commands

Gross says using certain IPCS commands can help users identify problems in the CICS environment. For example, VERBEXIT allows a user to invoke a routine provided by IBM for each specific release of CICS. With this keyword, a user can format the storage in the dump to format the display internal control blocks of CICS at the time of a failure. For storage issues, Gross says they will most likely want to look at the CICS Storage Manager control blocks. The VERBEXIT routine will give an overall summary of the control structures at the time of the failure and also allow a user to deep dive into the actual storage locations. “With this capability, the user can spend more time solving what went wrong, rather than sifting through an entire dump to find the right data to be reviewed,” he adds.

Another helpful command for looking at CICS dumps is the "LIST" command, says Gross. With this command, a user can look at any storage area within the CICS address space at the time of the failure. Although the VERBEXIT subcommand may show them where the problem is, ultimately, they may need to see the contents of the actual storage to determine what caused the problem, he explains.

IPCS Keeps CICS in Check

Accuracy and efficiency are vital to driving success, especially when interacting with clients and online transactions. With its ability to assist in debugging software failures within the z/OS operating system, IPCS is a robust diagnostic tool that, Gross says, ensures IBM Z^® continues to provide reliable results for users. While IPCS was not originally designed for use with CICS, the tool can easily be leveraged to improve performance by solving CICS software failures.