Envoy Application Programming Manual

Table Of Contents
Application Programming With Envoy
Envoy Application Programming Manual427159-001
1-4
Distributed Systems Management (DSM) Facility
Distributed Systems Management (DSM) Facility
Envoy supports the Distributed Systems Management (DSM) facilities provided by
Compaq for subsystem management. DSM provides two types of management
interfaces to subsystems:
Commands that perform operations on subsystem objects
Event messages that report significant events detected by the subsystem
Commands provide a two-way interface: a human operator or management application
sends a command to a subsystem, and the subsystem then performs some action and
returns a response to the operator or application. Event messages, on the other hand,
provide a one-way interface: information flows from the subsystem to the operator or
management application, but no information flows in the other direction.
For commands and for event messages, Envoy supports both interactive and
programmatic interfaces.
The Subsystem Control Facility (SCF) is an interactive interface that allows a human
operator to send DSM commands to Compaq data communications subsystems,
including Envoy. The Event Management Service (EMS) includes printing and
compatibility distributor processes that can print or display event messages for
operators. The ViewPoint console application includes screens that allow selective
viewing of event messages.
The DSM programmatic interfaces for sending commands (control and inquiry) and
retrieving event messages (event management) allow programs to perform the same kind
of monitoring and control operations that users of SCF, EMS printing and compatibility
distributors, and ViewPoint can perform interactively.
Figure 1-3
shows the relationships between DSM and the subsystem environment.
Figure 1-3. Overview of DSM Architecture
Management
Services
Operations
Environment
Subsystem
Environment
Operators
Subsystem Programmatic Interface (SPI)
Business
Applications
DSM
Tools
DSM
Applications
Management
Applications
DSM
Services
Compaq
Subsystems
Objects
CDT026.CDD
Objects