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

HP NonStop Event Management System 19
Flow of Event Messages
Two types of EMS processes manage the flow of event messages from the subsystem environment to the
operations environment:
• Event Message Collectors accept event messages from subsystems and log them. Pre-log filtration (PLF) lets
a primary or alternate collector use one or more filters to detect and discard all event bursts with specified
attributes or specific unwanted events that would otherwise be sent to the collector’s log file.
• Event Message Distributors filter event messages and return selected messages to the operations
environment.
Figure 3-3 shows the flow of event messages in a system:
1. Messages originate in the subsystems.
2. The subsystems send the messages to the primary and alternate collector processes.
3. Collectors write passed event messages to the log files.
4. Distributors retrieve selected messages from the log files and send them to processes, printers, terminals,
and other destinations in the operations environment.
The four kinds of distributors are each suited to a particular set of destination requirements:
• Forwarding
• Consumer
• Printing
• Compatibility
HP NonStop Event Management System