Planning your CICSplex to use z/OS Communications Server generic resources

You can use the z/OS® Communications Server generic resource function to balance terminal session workload across a number of CICS® regions.

You do this by grouping the CICS regions into a single generic resource. Each region is a member of the generic resource. When a terminal user logs on using the name of the generic resource (the generic resource name), z/OS Communications Server establishes a session between the terminal and one of the members, depending upon the session workload at the time. The terminal user is unaware of which member he or she is connected to. It is also possible for a terminal user to log on using the name of a generic resource member (a member name), in which case the terminal is connected to the named member.

APPC and LUTYPE6.1 connections do not log on in the same way as terminals. But they too can establish a connection to a generic resource by using either the generic resource name (in which case z/OS Communications Server chooses the member to which the connection is made) or the member name (in which case the connection is made to the named member).

When you plan your CICSplex to use z/OS Communications Server generic resources, you need to consider the following:
  • Which CICS regions should be generic resource members?
    Note that:
    • Only CICS regions that provide equivalent functions for terminal users should be members of the same generic resource.
    • In a CICSplex that contains both terminal-owning regions and application-owning regions (AORs), TORs and AORs should not be members of the same generic resource group.
  • Should there be one or many generic resources in the CICSplex?

    If you have several groups of users who use different applications, you may want to set up several generic resources, one for each group of users. Bear in mind that a single CICS region cannot be a member of more than one generic resource at a time.

  • Will there be APPC or LUTYPE6.1 connections. You are recommended to use APPC in preference to LUTYPE6.1 for CICS-to-CICS connections:
    • Between members of a generic resource? You cannot use LUTYPE6.1 connections between members of a generic resource.
    • Between members of one generic resource and members of another generic resource?
    • Between members of a generic resource and systems which are not members of generic resources?
    In all these cases you will need to understand when you can use:
    • Connection definitions that specify the generic resource name of the partner system
    • Connection definitions that specify the member name of the partner system
    • Autoinstall to provide definitions of the partner system.