Addressing OLTP Solutions with CICS: The Transaction Server ... - Ibm

114 CICS for AIX as the Transaction Server
the definitions for many different types of CICS systems or resources, easily
define the precise CICS system that is required, and then create it. Even when
the region has been destroyed, you can still re-create it even if you did not
export it first because CICS SM has a representation of what that CICS system
looked like. The terms and definitions of objects within CICS SM are geared to
creating this definitional view of the world.
Each CICS system to which you want to route work is defined by a system clone.
To create the system clones you define a system model, which specifies the
attributes common to the clones. There might be one system clone for
production systems, and another for test systems. Alternatively there might be a
clone for the system that runs the payroll system, and another for the ledger
system. The contents of the clones can be whatever is meaningful to your
installation. The system model undergoes the process of cloning to produce a
system clone. It is possible to clone a system model many times. Each system
clone represents a unique instance of the system model.
The concept of a model and clones also applies to the resources within CICS for
AIX, such as transactions or gateways. For example, there are transaction
models and transaction clones. To have an instance of a resource model, such
as a transaction, the resource model must be configured onto the system model.
When the system model is cloned, appropriate resource clones are created
automatically on the system clones, thus creating the mapping (needed for
workload management) between the resource that a user requests and the
systems on which it is available.
A group of system models and resource models and their associated system
clones and resource clones are known as a configuration. Each configuration
represents a possible implementation of a Plex, a named set of configurations. It
consists of CICS systems and resources with particular parameter settings. So,
for example, there might be one configuration for day and another for night.
Only one configuration within a Plex can be the target, that is, the group of
systems and resources with the characteristics that you intend to be up and
running. There might be a Plex covering the payroll system or the London
installation. This Plex would have the possible configurations within it. So, for
example, in our London Plex we might have weekday and weekend
configurations. The difference between the two configurations is that the
weekend configuration does not have the warehouse system active, only the
customer query system.
As we may want to share system or resource models between different
configurations, CICS SM has an object called a template, which is the highest
level of abstraction within a Plex. There are system templates and resource
templates. It is possible to create a system template from a system model. It is
then possible to create a new model based on that template in another
configuration. A similar process applies with resource models.
For information on the terms used within CICS SM see IBM CICS System
Manager for AIX Product Overview, GC33-1592-00.