Availability Guide for Problem Management

Problem Management Tools
Availability Guide for Problem Management–125509
9-8
Event Message Distributors
Event Message Distributors
EMS provides four distributor processes that collect event messages from the event log
file (or alternate log files). Three of these distributor processes format these messages
into operator messages and then distribute these operator messages to various
destinations.
Consumer Distributor
The consumer distributor is used by both Tandem and user-written applications to read
the EMS event messages in the EMS log file (or alternate log files), depending on the
filter specifications loaded to the distributor. The consumer distributor reads all events
and applies the filters to decide which events should be distributed and which should be
suppressed. The application can take appropriate action, if necessary, in response to an
important event. ViewPoint is an example of an operations console application that uses
the consumer distributor.
Printing Distributor
The printing distributor reads EMS event messages in the EMS log file (or alternate log
files) and formats the event messages into operator messages for logging to disk files,
terminals, or printers.
Compatibility Distributor
The compatibility distributor ($Z0) sends operator messages to a console device during
system load.
Forwarding Distributor
The forwarding distributor filters specific events and sends them to the EMS collector
process on another system in the network. The EMS collector process on the destination
system saves forwarded event messages in its EMS event log file.
What Are EMS Filters and How Are They Used?
The event log file is read by the EMS distributor processes configured onto or started on
the system. The consumer, printing, and forwarding distributors can use a filter to
determine whether to pass an event message to its destination (or destinations). The
distributor selects only the messages it wants by comparing each message to this filter. If
the distributor does not use a filter, all events are passed through.
For example, you can design a forwarding distributor that forwards only critical event
messages, a printing distributor that prints only action event messages, and a consumer
distributor that returns only Pathway event messages. EMS filters allow you to reduce
message traffic within a system and over a network by placing part of the program logic
as close to the source of event messages as possible. Rejected messages are skipped;
selected messages proceed to their destination.