When TSO is part of the sysplex environment and it exists on multiple sysplex members, the use of TSO through VTAM® can be extended to allow a generic name to be assigned to all TSO/VTAM application programs. A TSO/VTAM on one MVS™ system can be known by the same generic name as a TSO/VTAM on any other MVS system. All TSO/VTAM application programs sharing a particular generic name can be concurrently active.

Using a generic name allows for increased availability and workload balancing because all TSO/VTAM application programs can be accessed by the same generic name. For example, the MVS workload manager can be used to make efficient use of system resources by selecting a session partner based on balanced load distribution from among TSO/VTAM application programs with the same generic name.

An enhanced TSO reconnect function is also available; this function is dependent on a Job Entry Subsystem (JES) complex. A JES complex can be either a JES2 Multiaccess spool (JES2 MAS) or a JES3 processor complex. Either of these is a collection of host systems that share spool and other system facilities. For example, one piece of shared information is the identity and location of every TSO user address space. In a TSO/GR configuration, JES is asked for the system location of a disconnected TSO user when a reconnect logon request is submitted for the TSO generic name. The scope of visibility for JES is the JES complex. In this way, reconnect works in a predictable way for TSO/GR only when all members of the GR set are contained within one JES complex. This does not mean that you cannot have two, distinct TSO/GR sets with two, distinct JES complexes, but that arrangement is not recommended. Management is easier if you have only one JES complex for a parallel sysplex. Also, the TSO/GR set does not, and cannot, extend beyond the boundaries of a parallel sysplex.

When a generic name is used for TSO, unique names must be given to each of the TCAS, terminal control address space, APPL definition statements. The name TSO should not be used as the name on the TCAS APPL definition statement in any of the sysplex members. TSO is the TCAS ACBNAME in each sysplex member. Using TSO as the name on a TCAS APPL definition statement and as a generic resource member name can result in a local TCAS being selected rather than the generic member, whenever generic name resolution selects the member name TSO. The result is an unexpected distribution of TSO sessions in the generic resource environment.