Setting up and running a region status server

You can use a CICS® region status server to share CICS region status data in a sysplex rapidly to support optimized workload management. A region status server services only region status requests, rather than region status and user application requests.

About this task

CICS region status data is broadcast to the sysplex using a data table that is named after the hosting CICSplex for the region. Each region in the CICSplex is described by a single record in the CICSplex data table. The data tables are held in coupling facility structures, with access controlled by a coupling facility data table (CFDT) server. You must set up one CFDT server for each pool in an MVS™ image.

You can put related groups of region status tables in separate pools. For example, you might have one pool for production and another for test. A pool is defined as a list structure in the coupling facility resource management (CRFM) policy. The pool name is used to form the server name with the prefix DFHCF and is specified in the startup JCL for the server.

As best practice, your region status server and its pool name should be discrete from those used for user application purposes. Do not share the region status server and pool with user applications.

Considerations on the region status server pool name

The default pool name as implemented by CICSPlex® SM is DFHRSTAT. It is strongly recommended to use the default region status server pool name. You might want to use a pool name other than the default for the following scenarios:

You already have duplicate CICSplex names on the same sysplex as the region status server.
You are planning on having duplicate CICSplex names on the same sysplex as the region status server.
You have strict naming convention policies that prohibit use of the default pool name.
You have an environment that has multiple environments (for example, a test environment and a production environment) running on the same sysplex, requiring additional isolation.

When you do not use the default name DFHRSTAT, you must change the name before starting any other regions in the CICSplex. CICSPlex SM will not prevent you from changing the pool name while the CICSplex is active. If you make a change while the CICSplex is active, restart all CMAS and MAS regions (both routers and targets) in the CICSplex as soon as possible. Before all routers and targets have transferred over to the new region status server pool, WLM optimization is deactivated and routing requests will be non-optimized, even though some regions that have completed the migration might start showing as optimized. This means that you will see inconsistent data in the CICSPlex SM WLM views until all the regions in the CICSplex are restarted.

In addition, ensure that the relevant authorization is provided. See Security for coupling facility data tables.

Procedure

To set up a CICS region as a region status server, follow these steps:

Ensure that you have a list structure for a region status server pool.

Note: It is strongly recommended to use the default region status server pool name. You might want to use a pool name other than the default for the scenarios described in Considerations on the region status server pool name.
- For the best performance, define a new dedicated list structure for a region status server pool. For detailed instructions, see Defining a list structure for a region status server.
- Optionally, you can use an existing CFDT pool to store your CICSplex data tables. However, the throughput of your optimized workloads might be impeded by any user application activity to the specified pool name, and any application throughput to the pool might be affected by the sysplex optimized workloads.
Define a region status server start job and run the job in an MVS batch region.
For instructions, see Starting a region status server.

What to do next

Manage the region status server: After you have successfully started your region status server, you can control the region status server by using MVS MODIFY commands. For more information, see Controlling region status servers.
Delete a region status server: If required (for example, for a service upgrade, or for a clean sysplex restart), you can follow this instruction to delete a region status server.