Documentation Grafana documentation Alerting Introduction Alert rule evaluation State and health of alerts

State and health of alerts

There are three key components that help you understand how your alerts behave during their evaluation: alert instance state, alert rule state, and alert rule health. Although related, each component conveys subtly different information.

Alert instance state

An alert instance can be in either of the following states:

Notification routing

Alert instances will be routed for notifications when they are in the Alerting state or have been Resolved, transitioning from Alerting to Normal state.

No Data and Error alerts

When evaluation of an alert rule produces state No Data or Error, Grafana Alerting generates a new alert instance that have the following additional labels:

• alertname: Either DatasourceNoData or DatasourceError depending on the state.
• datasource_uid: The UID of the data source that caused the state.

You can manage these alerts like regular ones by using their labels to apply actions such as adding a silence, routing via notification policies, and more.

Lifecycle of stale alert instances

An alert instance is considered stale if its dimension or series has disappeared from the query results entirely for two evaluation intervals.

Stale alert instances that are in the Alerting, No Data, or Error states transition to the Normal state as Resolved. Once transitioned, these resolved alert instances are routed for notifications like other resolved alerts.

Modify the No Data or Error state

In Configure no data and error handling, you can change the default behaviour when the evaluation returns no data or an error. You can set the alert instance state to Alerting, Normal, or keep the last state.

Note that No Data and Error states are supported only for Grafana-managed alert rules.

Note that when you configure the No Data or Error behavior to Alerting or Normal, Grafana attempts to keep a stable set of fields under notification Values. If your query returns no data or an error, Grafana re-uses the latest known set of fields in Values, but will use -1 in place of the measured value.

Reduce No Data or Error alerts

To minimize the number of No Data or Error state alerts received, try the following.

1. Use the Keep last state option. For more information, refer to the section below. This option allows the alert to retain its last known state when there is no data available, rather than switching to a No Data state.

2. For No Data alerts, you can optimize your alert rule by expanding the time range of the query. However, if the time range is too big, it affects the performance of the query and can lead to errors due to timeout.

   To minimize timeouts resulting in the Error state, reduce the time range to request less data every evaluation cycle.

3. Change the default evaluation time out. The default is set at 30 seconds. To increase the default evaluation timeout, open a support ticket from the Cloud Portal. Note that this should be a last resort, because it may affect the performance of all alert rules and cause missed evaluations if the timeout is too long.

Keep last state

The “Keep Last State” option helps mitigate temporary data source issues, preventing alerts from unintentionally firing, resolving, and re-firing.

However, in situations where strict monitoring is critical, relying solely on the “Keep Last State” option may not be appropriate. Instead, consider using an alternative or implementing additional alert rules to ensure that issues with prolonged data source disruptions are detected.

grafana_state_reason for troubleshooting

Occasionally, an alert instance may be in a state that isn’t immediately clear to everyone. For example:

• Stale alert instances in the Alerting state transition to the Normal state when the series disappear.
• If “no data” handling is configured to transition to a state other than No Data.
• If “error” handling is configured to transition to a state other than Error.
• If the alert rule is deleted, paused, or updated in some cases, the alert instance also transitions to the Normal state.

In these situations, the evaluation state may differ from the alert state, and it might be necessary to understand the reason for being in that state when receiving the notification.

The grafana_state_reason annotation is included in these situations, providing the reason that explains why the alert instance transitioned to its current state. For example:

• Stale alert instances in the Normal state include the grafana_state_reason annotation with the value MissingSeries.
• If “no data” or “error” handling transitions to the Normal state, the grafana_state_reason annotation is included with the value No Data or Error, respectively.
• If the alert rule is deleted or paused, the grafana_state_reason is set to Paused or RuleDeleted. For some updates, it is set to Updated.

Alert rule state

The alert rule state is determined by the “worst case” state of the alert instances produced. For example, if one alert instance is Alerting, the alert rule state is firing.

An alert rule can be in either of the following states:

Alert rule health

An alert rule can have one of the following health statuses: