case study - moving cics applications (cicsplex)
Over the past two years, David Stephens and CPT Global have been working with a client to setup a CICSPlex from scratch. A CICSPlex is a specialised cluster that enables multiple CICS regions to communicate with each other and cooperate to handle inbound work requests providing many benefits including superior scalability and a single system image.
The presentation below is a case study in setting up a CICS based active-active application in a CICSPlex at the client. It covers topics such as the CICSPlex design, why it was chosen, and issues found. It describes application issues: from application changes needed, to user experiences with EXEC CPSM commands. It also includes operational challenges, from automation changes, to how the existing environment was migrated to CICSPlex. It also includes the results of resilience testing of the new environment.
At the client, three applications, each running in one CICS region, are now sharing workloads in two regions: active-active. There have been many decisions made and many issues, problems and errors encountered during the journey.
This presentation provides a fascinating insight into the steps needed to change the application and resources, together with problems faced, and some limitations of base software used.