IBM's latest update to the CICS transaction server contains the usual goodies, along with some other moves specifically for our increasingly mobile world.
Slow roll, or changing small chunks of the system instead of taking a big-bang approach, is becoming a mantra in many mainframe shops. With its inherent flexibility and distributed topology, IBM's Customer Information Control System (CICS) was already pretty good at it.
CICS Transaction Server (TS) 5.2 supports multiple application versions running on a single platform instance -- taking slow roll one step further. Some users can experience a new version of the application while others stick with the older one. The update also means that IT shops can consolidate dedicated quality assurance regions into the larger production environment.
The policy-based management introduced with CICS TS 5.1 now extends to new thresholds for syncpoints, transient data and temporary storage queues as well as task-elapsed time. Installations will more easily detect and purge runaway transactions by relying on this management scheme.
A lot of enterprises probably still sling clear-text security credentials around their internal network in tribute to the days when a user ID/password pair was the best way to get data from the mainframe. Now, CICS TS 5.2 incorporates and extends support for Security Assertion Markup Language (SAML) and Kerberos.
The SAML setup involves creating Security Token Server regions, resource definitions and Java virtual machines (JVMs). CICS provides an application interface through the linkable module DFHSAML. Despite the complicated setup, the SAML interface is useful because, as a Java design, it will run on specialty mainframe engines, potentially reducing costs.
The Kerberos support seems to be a little more straightforward. Either make changes in the Web provider pipeline definition, or write custom security handlers to extract information from the Kerberos token to take advantage of this security option.
Make it mobile
IBM's goal is to bring modern mobile-enabled application workloads onto the mainframe.
IBM folded the WebSphere Application Server (WAS) Liberty Profile, a lightweight version of WAS that lets programmers pick and choose which features to activate, into CICS with this update. The selectable configuration makes Liberty's direct-attached storage drive and memory footprints lighter, with faster startup time.
An IT organization can load Liberty as a Web application server inside of a CICS JVM, facilitating application portability between distributed WAS and the mainframe. It costs less than running a full-blown instance of WAS on System z, and eases the CPU load. Applications in Liberty directly access CICS resources, getting the business logic closer to where the data actually lives.
More configuration options
You might want to try a nontraditional CICS deployment if you're porting new workloads onto the mainframe or just starting out with mainframe servers.
CICS TS Developer Trial 5.2 is a free evaluation version of the product. While it is fully functional, the trial version does come with a few restrictions. For instance, the highest maximum task setting (MXT) is 30. CICS immediately resets any MXT attempts beyond that. I didn't see any specific restrictions against doing production work, but the trial version does have an unspecified expiration date. To get CICS back after it expires, you would reorder the trial version and install the activation module.
The CICS Value Unit Edition (VUE) offers a onetime charge option on z New Application License Charge (zNALC) logical partitions (LPARs). The intent is to make the mainframe more attractive for traditionally distributed applications.
The user must install CICS VUE and the VUE entitlement module, and the VUE CICS must run on a zNALC LPAR. IBM has a specific understanding of "new workload," as in WAS for z, SAP, PeopleSoft, Siebel or Domino.
An additional hurdle for the VUE option is IBM's certification process that examines what a shop is doing on the mainframe.
About the author:
Robert Crawford spent 29 years as a systems programmer, covering CICS technical support, Virtual Storage Access Method, IBM DB2, IBM IMS and other mainframe products. He programmed in Assembler, Rexx, C, C++, PL/1 and COBOL. Crawford is currently an operations architect based in south Texas, establishing mainframe strategy for a large insurance company.
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