SNAX/APC Configuration and Management Manual

Introduction to SCF for SNAX/APC
SNAX/APC Configuration and Management Manual—138787
6-3
Subsystem Control Point (SCP)
•
Subsystem environment, in which subsystems (such as SNAX/APC) and the objects
they control are managed
•
Management services, which are software products that support the programmatic
interface between the two environments
SCF is a DSM management tool in the operations environment. It is a unified command
interface that simplifies the tasks of configuring, controlling, and collecting information
about Tandem subsystems.
When you use SCF, you can choose either to let a person perform an action or to
automate that action, as represented by the terminal and the command (OBEY) file,
respectively, shown in Figure 6-1
. SCF returns display and error-message output to a
terminal or to a log file.
The management services depend on the Subsystem Programmatic Interface (SPI) for
communication between the operations and subsystem environments. SPI is a standard
set of procedures and associated definition files used to define common message-based
programmatic interfaces for communication between requesters and servers—for
instance, in a management application. SPI includes procedures to build and decode
specially formatted messages using tokens. SCF is a management application, provided
by Tandem, that uses SPI internally.
Subsystem Control Point (SCP)
The Subsystem Control Point is a network-management process for receiving and
redistributing the messages that SCF sends to certain data communications subsystems.
The SCP process operates between SCF and Tandem data communications subsystems.
SCP provides security (by restricting access to sensitive commands), version control,
and tracing support for subsystems, and it supports NonStop application processes.
SCP can be used in two ways: interactively and programmatically. The interactive
interface is provided so you can choose to let a person perform an action or automate the
action.
The programmatic interface is based on the requester-server model and the use of
tokenized messages rather than text. The programmatic interface is used for control and
inquiry as well as for event-management functions. The interface is described in the SPI
Common Extensions Manual.
The programmatic interface is based on the Subsystem Programmatic Interface (SPI),
which provides procedures that build and retrieve information from command, response,
and event-message buffers. SPI is described in the SPI Programming Manual.
SCF Commands
Some SCF commands operate on the objects (lines, subdevices, processes, and so forth)
belonging to each subsystem. In the SNAX/APC subsystem, for example, the ADD and
DELETE commands add objects to and delete objects from the list of objects controlled
by SCF. Once an object is subject to control by SCF, you can use the START, STOP,
and ABORT commands to change the state of the object, or you can use the ALTER
command to change the values of selected attributes of the object. You can also use the