docs/sources/shared/alerts/modify-error-state.md
Set Error state (Default)
If the pending period is 0, the alert instance transitions immediately to Error. Otherwise, it transitions to the Pending state, and then to Error after the pending period has elapsed and the last evaluation returns an error.
When entering the Error state, the alert rule creates a new DatasourceError alert instance with labels for the alert rule name, UID, and data source UID.
Set Alerting state
If the pending period is 0, the alert instance transitions immediately to Alerting. Otherwise, it transitions to the Pending state, and then to Alerting after the pending period has elapsed and the last evaluation returns an error or a threshold breach.
Set Normal state
The alert instance transitions immediately to the Normal state.
Keep last state
The alert instance keeps its current state.