ViewPoint Manual

Functional Description
ViewPoint Manual—426801-001
5-35
Summary of Event Operations
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Logging a current event
The subsystem that generated the event sends an event message to the node’s event
collector, which records the event message in the current log file.
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Transferring event messages to the NCN
The forwarding distributor gets the current log file name from the event collector,
reads newly logged event messages from the log, puts them through the distributor
filter, and (if they pass) sends them to the NCN event collector. The NCN event
collector records these messages in its current-events log—along with messages
coming from other nodes—in the order received.
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Presenting the event
The primary events distributor reads newly logged event messages from the NCN
event log. If an event matches the filter that is currently loaded (for all operators),
the event message is passed to your operator task in the event collection server. The
event collection server puts the message into the primary-events cache stored in its
memory. If you select the END page of the primary-events display, the page in the
cache that contains the most recent events is sent to the ViewPoint TCP for display
on your terminal. If you request an earlier page, that page from the cache is sent.
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Presenting the last events
The last-events distributor also examines newly logged event messages. If these
newly logged event messages pass, the currently installed filter (which specifies the
desired set of subjects) passes these messages to an event collection server. Passing
the messages to an event collection server puts the messages into the last-events
database, where they are sorted and stored according to subject name.
Thus, these records can be retrieved to show the most recent events for a given
subject. Presenting last events for a subject begins when you request the Last
Events screen, specifying a particular subject and pressing the Last Events function
key. Your events-display process reads a full page of event messages (or less if the
wrap-count for the specified subject is less than 16) from the last-events database
and passes it to the ViewPoint TCP for display on your terminal.
•
Loading an alternate event
An alternate filter gets specified on the Alternate Event Configuration screen. When
you press the Configure function key to accept this new configuration parameter, the
filter is loaded from the specified filter object file.
•
Presenting historical events
The display of historical events begins when you request (on the Event
Configuration screen for alternate events) a particular starting time (After field),
plus possibly a node name and a collector name. This causes an alternate-events
distributor process to be created for you, associated with the current (or specified)
collector. (If you happen to have a distributor process elsewhere, it is stopped at this
time.) Then, the After field information is forwarded through the event collection
server to the new distributor. If the distributor does not have the file name for the
file that corresponds to your specified date and time, it requests the collector for that
name.
Once the distributor has the log file name, the distributor can access the log file,
beginning at the specified time, and it begins to retrieve event messages for your
alternate-events display. These messages are sent to the event collection server,