Events are special messages that inform you of the state of your system. As events are generated, they are routed through the monitoring system so that you can see them. There are four types of events that the store reports:

1. State Change events are issued when a service starts up or shuts down.

2. Performance events report statistics about the performance of various services.

3. Log events are records produced by the various system components to provide trace information about debugging. These records are produced by the standard java.util.logging package.

4. Plan Change events record the progress of plans as they execute, are interrupted, fail or are canceled.

You cannot view Plan Change events directly through Oracle NoSQL Database's administrative interfaces. However, State Change events, Performance events, and Log events are recorded using the EventRecorder facility, which is internal to the Admin. Only events considered critical are recorded, and the criteria for being designated as such varies with the event type. These are the events considered critical:

• All state changes.
• Log events classified as SEVERE.
• Any performance events reported as below a certain threshold.

You can view all of these critical events using the Admin CLI show events and show event commands.

Use the CLI show events command with no arguments to see all of the unexpired events in the database. Use the -from and -to arguments to limit the range of events that display. Use the -type or -id arguments to filter events by type or id, respectively.

For example, this is part of the output from a show events command:

kv-> show events

Output:

idarpdfbS STAT 2024-04-05 22:18:39.287 UTC sn1 RUNNING sev1
idarpeg0S STAT 2024-04-05 22:18:40.608 UTC sn2 RUNNING sev1
idarphmuS STAT 2024-04-05 22:18:44.742 UTC rg1-rn1 RUNNING sev1
idarpjLLS STAT 2024-04-05 22:18:47.289 UTC rg1-rn2 RUNNING sev1
idartfcuS STAT 2024-04-05 22:21:48.414 UTC rg1-rn2 UNREACHABLE sev2
                                                   (reported by admin1)

This result shows four service state change events (sev1) and one log event (UNREACHABLE), classified as sev2. Tags at the beginning of each line are individual event record identifiers. To see detailed information for a particular event, use the show event command, which takes an event record identifier, such as idartfcuS as its argument:

kv-> show event -id idartfcuS

Output:

idartfcuS STAT 2024-04-05 22:21:48.414 UTC rg1-rn2 UNREACHABLE sev2
  (reported by admin1)

Using this method of event identifiers, you can see a complete stack trace.

Events are removed from the system if the total number of events is greater than a set maximum number, or if the Event is older than a set period. The default maximum number of events is 10,000, while the default time period is 30 days.

Both Sev1 and Sev2 flags are associated with specific service state change events. Sev1 flags report the current state. Sev2 flags report errors during attempted state changes, as follows: