Alerting Engine and Rules Guide  Alerting is only available in Grafana v4.0 and above.
Introduction     Alerting in Grafana allows you to attach rules to your dashboard panels. When you save the dashboard Grafana will extract the alert rules into a separate alert rule storage and schedule them for evaluation.
In the alert tab of the graph panel you can configure how often the alert rule should be evaluated and the conditions that need to be met for the alert to change state and trigger its notifications.