CICS policies

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

CICS policies bring together the following features introduced in earlier CICS TS releases:

System events, which help you understand and manage the health and availability of your CICS system. Events are emitted to notify you when system health or system resource state changes.
System events are superseded by policy system rules. For more information, see Using policy system rules to replace system events.
CICS policy task threshold rules, which help you identify excessive resource usage by individual user tasks and help to automatically respond when that resource usage exceeds a threshold you define.
CICS policy task threshold rules are now referred to as policy task rules.

Types of policy rules

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

System 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 four actions: message, event, reject request, or set z/OS WLM health open status. For more information about the system rules that are supported, see Policy system rules.
Task 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.

You can define system and task rules in the same policy, but it is advisable to define the two types of rule in separate policies if you want to deploy the policies with a CICS platform or with a CICS application, or to further restrict the scope of task rules installed in a stand-alone CICS region by defining policy scopes.

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 stand-alone CICS region: Policies that define task and system rules can be installed as a CICS BUNDLE resource defined in the CICS system definition data set (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.

Using CICS Explorer to define CICS policy rules

All policy rules are defined through the policy definition editor available in CICS Explorer®. This editor supports the creation, modification and deletion of both system rules and task rules and can be used to modify any policy created by the deprecated policy definition wizard supplied with older versions of CICS Explorer. To enjoy full support for CICS policies, use CICS Explorer 5.4.0.6 or later. For further information, see The policy definition editor of CICS Explorer.