|
The FOCUS Multi-Session Option is a software platform that allows multiple FOCUS users to run in a single MVS address space. MSO communications services allow different terminal environments to talk to FOCUS sessions in MSO; terminals in the CICS, TSO, or VTAM environments are supported. |
Topics: |
The basic FOCUS programs in the OS/390 environment are identical for both MSO and TSO FOCUS. Because the same programs are used when either an MSO or a TSO user accesses FOCUS, the overall resources consumed by FOCUS functions are essentially the same for both. In fact, for most FOCUS users, operating under MSO is indistinguishable from operating under TSO. However, since OS/390 treats swappable TSO FOCUS users differently than non-swappable MSO FOCUS users, it is possible for TSO and MSO response time characteristics for the same FOCUS application to vary greatly. Generally, the choice depends on resources available to the FOCUS application, as well as the site's tuning parameters.
Each FOCUS user requires a substantial user data area that cannot be shared. These data areas are the main factors in determining how to plan for resource requirements for FOCUS in the MSO environment. CPU and I/O requirements depend on the particular FOCUS applications being used, and are not dependent on the FOCUS environment (either MSO or TSO). This means that only real and virtual memory requirements must be taken into account for MSO capacity planning.
| Information Builders |