gtpm6m0s | Main Supervisor Reference |
The High Performance Option (HPO) is a licensed feature available to TPF users. HPO is composed of 2 subfunctions:
The multiple database function (MDBF) enhances portability, protection, and sharing of system resources. It consists of 2 distinct, yet related, operating modes; subsystems (SS) and subsystem users (SSU). Users can configure as many as 64 subsystems or 127 subsystem users. The combination of subsystems and subsystem users cannot exceed 128. Each subsystem owns independent disk packs (DASD) while sharing control program services with other subsystems. For ease of control, one subsystem contains all the system related software. This subsystem is called the basic subsystem (BSS). Base TPF systems (without HPO) consist of a single BSS with no subsystem users.
Both subsystems and subsystem users contain E-type (online) programs, V-type (offline) programs, and a database. A database can consist of fixed files, pool files, user global area(s), application control data, and system control data.
There are several different variations of MDBF systems, ranging from one basic subsystem with one or more subsystem users, to multiple subsystems with multiple subsystem users.
The loosely coupled (LC) facility provides the potential for 8 processors to access a shared database while presenting the outward appearance of a single processor. Database sharing is accomplished by one of 2 hardware RPQs: the limited lock facility (LLF) or the concurrency filter lock facility (CFLF). CFLF is a companion feature to the 3990 Storage Control Multi-Path Record Cache RPQ. A Sysplex Timer (STR) or a second RPQ (necessary for interprocessor clock synchronization) is also required in a loosely coupled system.