Managing applications

Use CICS Explorer® to manage installed applications.

In this section, find out how to:

For information about securing application resources, see Security for platforms and applications.

Make a new version of an application available

When you make changes to the CICS® bundles for the components of an application, you then update the versions of the CICS bundles, the application, and the application binding, and deploy the new versions on the platform.

Use CICS Explorer to update your CICS bundles, to update the application bundle and the application binding. Follow the information in Updating CICS bundles in the CICS Explorer product documentation.

Be aware of the following considerations:
  • You must apply a versioning policy to your CICS bundles, application bundles, and application bindings to deploy and manage updates in the CICS environment. You cannot use an existing version of an application bundle to install new versions of the CICS bundles for the application, and you cannot use an existing version of an application binding with a new version of an application bundle. You must update the versions of the application bundle and application binding whenever you update the CICS bundles for the application. For information, see Assigning a version to your applications.
  • All the projects related to the application must be present in your local workspace for CICS Explorer, including the platform project for the target platform. CICS Explorer requires the platform project in order to validate the application project and the application binding project.
  • If your application uses only private resources, you can install and make available multiple versions of the application at the same time, on the same platform. If your application uses resources that are not supported for multi-versioning, you must disable and discard the installed APPLCTN resource that represents the previous version of the application before you install a new version. Alternatively, consider renaming the resources that are not supported for multi-versioning, so that they do not conflict with the resources installed for previous versions of the application.
  • If you disable an application in order to install a new version, it is unavailable to users from the time when you make the previous version of the application unavailable in order to disable and discard the installed APPLCTN resource in the CICSplex, to the time when you install the new APPLDEF resource definition, enable the new version of the application, and make it available. Plan a suitable time when this can safely occur, or plan an alternative solution for users of the application during that time.
  • You can either update the existing application binding to specify the new version of the application, or create a new application binding for the new version of the application. You can also change the deployment of the CICS bundles for the application into the region types in the platform.
  • When you make a new version of an application available, CICS allows callers (such as CICS transactions or other linking applications) to access the application version through the CICS resources that are declared as its application entry points. By default, CICS provides callers with the highest version of the application that is available on the platform. For applications that are supported for multi-versioning, if multiple versions are available, callers can either access the highest available application version, or use the EXEC CICS INVOKE APPLICATION command to specify any available application version. For more information about invoking a specific version of an application, see Invoking a multi-versioned application.

Make unavailable, disable and discard an application

To temporarily remove platform users' access to a version of an application, make the application version unavailable. If you do not plan to give users access to the application version again soon, but you want to keep it installed, disable it. If you no longer require the application version, discard it.

In CICS Explorer, you can see the status of the application. Follow the information in Making unavailable, disabling, and discarding applications.

Be aware of the following considerations:
  • When you make a version of an application unavailable or disable or discard it, the instances of the CICS bundles that were installed for that application version are also made unavailable, disabled, or discarded in the CICS regions. Other versions of the application, or other applications, that use the same CICS bundles are not affected.
  • The application definition remains in the data repository for the CICSplex.
  • If you disable an application in order to install a new version, it is unavailable to users from the time when you make the previous version of the application unavailable in order to disable and discard the installed APPLCTN resource in the CICSplex, to the time when you install the new APPLDEF resource definition, enable the new version of the application, and make it available. Plan a suitable time when this can safely occur, or plan an alternative solution for users of the application during that time.
  • After you make an application unavailable or disable or discard it, choose what to do with it:
    • If you no longer require the application version, you can delete the application definition that points to that version of the application. You do not have to delete previous versions of the application definition when you install a new version of the application, or when you discard a platform. You must make unavailable, disable, and discard the relevant version of the application before you can delete an application definition.
    • If you no longer require the application version, you can delete the exported version of the application project from the platform directory in zFS. Use the z/OS® perspective in the CICS Explorer to delete the folder containing the relevant version of the application bundle from the platform home directory.
    • If you no longer require the CICS bundles for the components of the application version, you can delete the exported versions of the CICS bundle projects from the platform home directory. Check first that the versions of the CICS bundles are not being used by any other versions of the application, or by any other applications, or by the platform.

Use application context data to monitor applications

When a CICS task enters an application through one of the application's entry points, application context is associated with the task. This task application context is available in the performance records that the CICS monitoring facility writes to SMF and includes data fields about platforms, applications and their versions. You can use the application context to help with charge-back accountancy, performance monitoring, capacity planning and problem determination.

See Application context for information about the conditions for application context and how to view the current application context. IBM Redbooks: Cloud Enabling IBM CICS shows some examples of using application context with the CICS sample General Insurance Application (GENAPP). For information about CICS monitoring facility, see Introduction to CICS monitoring.

To make use of the application context in the CICS monitoring facility performance records, you need the following:
  • Monitoring enabled on your running CICS TS regions. For example, by setting SIT parameters MN=ON and MNPERF=ON, or CEMT SET MON ON PERF, or setting the Monitoring Status and Performance Monitoring Status fields in CICS Explorer.
  • One or more applications installed, enabled and available on your CICS TS region.
  • A software product that can process CICS monitoring facility performance records, for example, CICS Performance Analyzer.