Decision Runtime for z/OS environments

You can create decision services in Operational Decision Manager, and run them in Decision Runtime for z/OS, which provides rule execution options for mainframe applications.

In Operational Decision Manager, you can create decision services that contain business rules, and then run these rules in one of the following Decision Runtime for z/OS environments:
  • zRule Execution Server for z/OS
  • zRule Execution Server for z/OS on CICS® JVM server

Choose the rule execution environment by assessing your needs, goals, and existing architecture.

zRule Execution Server for z/OS

In this rule execution environment, you offload rule execution from your z/OS® applications (COBOL or PL/I applications) to zRule Execution Server for z/OS, where your rules are executed on a server running a JVM.

zRule Execution Server for z/OS supports both batch and transactional clients. You can run your client applications in the following ways:
  • As a batch job.
  • As an IMS application that runs in a message processing region (MPR) or a batch message processing (BMP) region, or that uses Data Language/Interface (DLI) calls.
  • As an application that runs on CICS Transaction Server for z/OS.

zRule Execution Server for z/OS instances are configured as server groups. If a server becomes inactive, rule execution transfers automatically to the next group member that is connected to the application. When the server restarts, rule execution transfers back to the original server. No action is required by the application to do these transfers.

To run Operational Decision Manager business rules with zRule Execution Server for z/OS follow these steps:

  1. Remove the embedded rules from your applications.
  2. Create rule projects in Rule Designer, and author the rules by using a business object model (BOM) from a programming language model for z/OS, like COBOL or PL/I.
  3. Deploy the rules to the zRule Execution Server for z/OS persistence layer (typically a database) by using Rule Designer, the Rule Execution Server console, or Decision Center on the distributed platform.
  4. Add API calls to your z/OS applications and pass the input data to the execution server. The applications use the APIs to connect to the rule execution server, execute the rules, and then disconnect from the server.
  5. Resolve the API calls by including API stubs in the load modules for your applications. There are API stubs for batch, CICS, and IMS applications.

The following figure illustrates how z/OS applications call zRule Execution Server for z/OS to execute the business rules and return the resulting decision:

zRule Execution Server for z/OS comes with a web-based console for rule deployment and management so it is easy to update and redeploy rules as business needs change.

This execution environment is the best choice if you currently run z/OS applications as IMS, batch, or CICS Transaction Server for z/OS applications.

zRule Execution Server for z/OS on a CICS JVM server

If you are using CICS Transaction Server for z/OS, you also have the option of running your z/OS applications on zRule Execution Server for z/OS on a CICS JVM server. To execute rules, you follow the same steps as you do for zRule Execution Server for z/OS. However, this rule execution environment gives you access to the system management and configuration capabilities of CICSPlex® System Manager (CPSM). Using CPSM, you can route rule execution requests to multiple zRule Execution Server for z/OS instances in multiple CICS regions.

Note: zRule Execution Server for z/OS on CICS JVM server can be configured only as a server group with a single server. Therefore, rule execution cannot be transferred to another member if a server becomes inactive.

The following figure illustrates how z/OS applications call zRule Execution Server for z/OS on a CICS JVM server to execute business rules and return the resulting decision:

This execution environment is the best choice if you are already using a CICS Transaction Server and you need the capabilities of CPSM.