Designing a CICS application for deployment to a platform
Before you create an application for deployment to a platform as part of a CICS® cloud solution, identify how you plan to structure the application. For example, consider what resources to bundle with the application or declare as dependencies for it, what application entry points to provide for access to the application, where the application will be deployed, and whether you plan to run multiple versions of the application concurrently.
Identifying application entry points
- The earlier in the transaction flow that you identify that a task is part of an application, the sooner you can apply policies and start monitoring for the cost of the application. This can be of particular importance if the application spans multiple CICS TS regions. To monitor the application across all of the CICS TS regions that it touches, the entry points should be defined on the CICS TS region that first accepts the inbound request.
- An application can have different functions that it performs. These are referred to as the operations of the application, for example, inquiring on a customer. There can be value in identifying these operations, and monitoring or applying policies to individual operations.
Which resources should be defined in CICS bundles?
Defining resources in a CICS bundle is an important step, because the management and lifecycle of those resources is delegated to the CICS bundles and management bundles that installed the resources. You no longer modify the resources or change their state individually, because they are automatically added, updated, or removed when you operate on the CICS bundles and the application. Application architects must therefore carefully consider which resources for an application should have their lifecycle tied to the lifecycle of a CICS bundle.
Review the information in Characteristics of bundled resources to help you choose which resources to define in CICS bundles and how to arrange them. If your application uses resources that cannot be defined in a CICS bundle, or that you do not want to define in a CICS bundle, you can continue to specify these as imports.
For supported resource types, a CICS resource is private if the resource is defined in a CICS bundle that is packaged and installed as part of an application. Because these resources are not available to any other application or version installed on the platform, or to other applications in the CICS region, the resource name does not have to be unique in your installation. Review the information in Private resources for application versions to understand the changes to behavior and management for private resources. If you do not want a resource of the supported resource types to be private, continue to specify it as an import.
Which bundles are installed where?
Which bundles are in the application and which bundles are added in the application binding, as an alternative to deploying them with the application or adding them to the platform? These might include policies or resource definitions that control or customize the behavior of the application for the target platform.