Alert rule state and health

Each alert rule can generate one or more alert instances—one alert instance for each series or dimension, as shown in the multi-dimensional alert example.

Each alert instance of the same alert rule represents a different target and can be in a different state; for example, one alert instance may be Normal while another is Alerting.

{{< figure src="/media/docs/alerting/alert-rule-example-multiple-alert-instances.png" max-width="750px" alt="Multi dimensional alert rule. The alert rule state and alert rule health are determined by the state of the alert instances." >}}

The alert rule state and alert rule health are determined by the state of the alert instances.

Alert rule states

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

State	Description
Normal	None of the alert instances returned by the evaluation engine is in a Pending or Alerting state.
Pending	At least one alert instances returned by the evaluation engine is Pending.
Firing	At least one alert instances returned by the evaluation engine is Alerting.

Alert rule health

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

State	Description
Ok	No error when evaluating the alert rule.
Error	An error occurred when evaluating the alert rule.
No Data	The alert rule query returns no data.
{status}, KeepLast	The rule would have received another status but was configured to keep the last state of the alert rule.