OVNM 5.3 - Operations Agent for NonStop Event Management Guide for UNIX

HP NonStop Event Management System 13
Figure 3-1 is a simplified diagram of the EMS layer, its components, and their relationships to the subsystem and
operations environments.
Figure 2-1 EMS in the System Environment
2-1-2 EMS Communications in the DSM Environment
EMS uses two types of interfaces to communicate with other components of DSM (for example, ViewPoint) and
with processes that use DSM to manage a system or network:
• EMS Interface
This interface manages event reporting in a system or network. It is the mechanism used to send event
messages to EMS. Subsystems, HP or user-written applications, and DSM processes (such as ViewPoint and
DNS) use it to send event information to the EMS primary collector by subsystems. EMS processes
themselves use this interface to report event information to the primary collector.
• Command-Response Interface
This interface is used to issue commands and receive responses about resources in a system or network. HP
or user-written management applications can use the command-response interface. For example, a
management application can issue a command to a subsystem to open a communication line.
Figure 3-2 is a simplified diagram of the lines of communication between the components of a DSM system.
Figure 2-2 EMS and Command-Response Interfaces
The major EMS processes (such as collectors and distributors) are controlled through the command-response
interface.
Both the EMS and command-response interfaces are based on the Subsystem Programmatic Interface (SPI)
message format. (See the SPI Programming Manual.) The common message format for event messages and
commands supported by SPI simplifies the learning and programming tasks for programmers who deal with both
interfaces.
HP NonStop Event Management System