CICS policies

The behavior of CICS® can be controlled during run time, based on predefined policies. CICS performs the action that is defined in the policy when all the conditions specified in the policy are met.

Policies define the action that CICS is to take when one of the following conditions is met:
  • A CICS user task makes excessive use of system resources; for example, a user task consumes too much storage.
  • A CICS system or user task changes the state of a system resource; for example, a FILE resource is closed.
  • The overall system health changes; for example, the number of active task exceeds the maximum user tasks in the CICS system (the MXT value).

A condition and action pair make up a policy rule, and one or more policy rules can be defined within a policy. A policy is defined in a CICS bundle and a CICS bundle can consist of one or more policies. For more information, see Creating and deploying a policy in a CICS Bundle project in the CICS Explorer product documentation.

Policy rules

CICS supports two types of policy rules: system rules and task rules.

Use system rules to monitor the state of critical system resources or the overall health of a CICS system and to respond automatically when any changes occur. System rules support two actions: message or event. For more information about the system rules that are supported, see Policy system rules.

Use task rules to monitor the resource utilization of individual user tasks and to automatically respond when a tasks resource usage exceeds a pre-defined threshold. In this way, excessive resource usage, and looping transactions can be detected and dealt with appropriately. Task rules support three actions: message, event, or abend. For more information about the task rules that are supported, see Policy task rules.

Scope and deployment of policies

All deployed policies have a specific scope that controls which CICS tasks they apply to. Policies are defined in CICS bundles, which can be deployed in the following ways:
Deployed into a single CICS region
Policies that define task and system rules can be installed as a CICS BUNDLE resource defined in the CSD or CICSPlex® SM data repository and installed in any CICS region.

By default, policies that define task rules that are deployed in this way apply to all CICS user tasks running in the region. However, you can restrict task rules to specific user tasks by defining a policy scope in the CICS bundle manifest. For more information, see Restricting a policy to specific user tasks in a stand-alone CICS region in the CICS Explorer product documentation. Policies that define system rules deployed in this way apply to all CICS tasks running in the region.

Deployed during platform installation
Policies that define task and system rules can be packaged with a platform bundle and deployed when the platform is installed.

Policies that define system rules and are deployed in this way apply to all CICS tasks that run in all the CICS regions within the platform to which the policies are deployed. However, policies that define task rules apply to only the CICS user tasks for CICS applications installed on the platform.

Deployed during application installation
Policies that define task rules can be packaged with an application bundle and deployed when the application is installed on a platform. These rules apply only to the CICS user tasks for that application. You can further restrict task rules to user tasks for a specific application operation by defining a policy scope in the CICS bundle manifest. Policies that define system rules cannot be packaged with an application bundle.

For more information, see Policy scopes.