The Alert Routing Server dispatches alerts about network components in The Things Stack.
Alert Dispatch
The Alert Routing Server deals only with the dispatching alert notifications. The alert notifications are not generated by the Alert Routing Server, but by external alert generators. The notifications strictly refer to individual entities in this form.
The Alert Routing Server looks up the alert notification profile associated with the entity related to the alert notification. If no profile is associated with the entity, the default alert notification profile is used. If no default alert notification profile is present, the alert notification is dropped.
For every alert notification receiver, a dedicated alert notification is generated and stored in a FIFO queue. These notifications are will be sent in order to the alert notification receiver. The delivery will be automatically retried, for a fixed number of times.
Alert Generators
As the alert notifications are not generated by the Alert Routing Server, another component must create them. The generator is responsible for both opening and closing these alerts, as well as sending periodic status updates which the Alert Routing Server dispatches.
Prometheus and Alertmanager
Prometheus and Alertmanager are used to generate and manage alerts. Prometheus opens and closes the alerts, while Alertmanager manages automatic status updates for the alert.