There are those events that clear automatically, such as CPU Utilization and those events that must be manually cleared, either through the Incident Manager UI or automatically via rule (such as Job Failure, or Log Metric events). Auto-clear events, as the term implies, are cleared automatically by Enterprise Manager once the underlying issue is resolved. In the case of CPU Utilization, the event CPU Utilization clears automatically once the percent utilization falls below the warning threshold. However, for those events that must be cleared manually, a user must intervene and clear the event using Incident Manager either by selecting the incident/event and clicking Clear, or creating an event rule to do the job (recommended method).

As mentioned previously, an event rule automates the clearing of manually clearable events. Enterprise Manager provides a limited number of out-of-box rules that automatically clear manually clearable events, such as job failures or ADP events that remain open for seven days. However, to more accurately meet the needs of your monitoring environment, Oracle recommends creating your own event rules to automatically clear those manually clearable events that are most prevalent in your environment.

During the rule creation process, you can specify that an event be automatically cleared by selecting the Clear Event option while you are adding conditional actions.

Getting Notified when the Event Clears

The event clearing action is an asynchronous operation, which means that when the rule action (clear) is initiated, the manually clearable event will be enqueued for clearing, but not actually cleared. Hence, an email notification sent upon rule execution will indicate that the event has not been cleared. Asynchronous clearing is by design as it reduces overall rule engine processing load and processing time. Subscribing to this event clearing rule with the intent to be notified when the event clears will be of little value. If you want to be notified when the event clears, you must create a new event rule and explicitly specify a Clear severity. In doing so, you will be notified once the event is actually cleared.