To manually inspect which alerts are active (pending or firing), navigate to the Alerts tab of your Prometheus instance. This will show you the exact label sets for which each defined alert is currently active.
Alerting rules
Alerting rules allow you to define alert conditions based on the Prometheus expression language and to send alerting notifications to an external service. As long as all monitored metrics move within the set limits, the alerts are inactive:
You can filter alerts by status ① or by name ②. Check the checkbox ③ to display only the annotations of the set alerts.
Pending state
Pending state means the state of an alert that has been active for less than the configured threshold duration. This threshold is configured in the Fire alert... field of the Custom alerts in the Alert_Configuration form. For default alerts, the threshold is set to 35 seconds.
The "Value" ④ indicates a measured pitch that is outside the set range.
The "Active Since" ⑤ indicates a measured pitch that is outside the set range.
The "Labels" clause ⑥ allows specifying a set of additional labels to be attached to the alert.
Firing state
Firing state means the state of an alert that has been active for longer than the configured threshold duration.
Note:
For pending and firing alerts, Prometheus also stores synthetic time series of the form ALERTS{alertname="", alertstate="", }. The sample value is set to 1 as long as the alert is in the indicated active (pending or firing) state, and the series is marked stale when this is no longer the case.