Simple event throttling provides a mechanism to protect event receivers from being overloaded when a scenario causes many events to be generated in a very short period of time. A throttling rate (events/seconds) can be configured. Specific application events can be configured to be throttled. When the throttling event limit is exceeded in a throttling interval, any further events of that type are dropped and the dropped events counter is incremented. Dropped events counts are displayed with the show>log>event-control command. Events are dropped before being sent to one of the logger event collector tasks. There is no record of the details of the dropped events and therefore no way to retrieve event history data lost by this throttling method.
A particular event type can be generated by multiple managed objects within the system. At the point that this throttling method is applied, the logger application has no information about the managed object that generated the event and cannot distinguish between events generated by object "A" from events generated by object "B". If the events have the same event-id, they are throttled regardless of the managed object that generated them. The logger application also cannot distinguish between events that will be logged to destination log-id <n> from events that will be logged to destination log-id <m>.
Throttle rate applies commonly to all event types. It is not configurable for a specific event type.
A timer task checks for events dropped by throttling when the throttle interval expires. If any events have been dropped, a TIMETRA-SYSTEM-MIB::tmnxTrapDropped notification is sent.
By default, event throttling is set to off for each specific event type. It must be explicitly enabled for each event type where throttling is needed. This makes backwards compatibility of configuration files easier to manage.