Alerting | Prometheus
https://prometheus.io/docs/practices/alertingAccordingly, have alerts to ensure that Prometheus servers, Alertmanagers, PushGateways, and other monitoring infrastructure are available and running correctly. As always, if it is possible to alert on symptoms rather than causes, this helps to reduce noise. For example, a blackbox test that alerts are getting from PushGateway to Prometheus to ...
Prometheus: understanding the delays on alerting
pracucci.com › prometheus-understanding-the-delaysAt each evaluation cycle, Prometheus runs the expression defined in each alerting rule and updates the alert state. An alert can have the following states: inactive: the state of an alert that is neither firing nor pending; pending: the state of an alert that has been active for less than the configured threshold duration; firing: the state of an alert that has been active for longer than the configured threshold duration
Alerting rules | Prometheus
prometheus.io › docs › prometheusFor pending and firing alerts, Prometheus also stores synthetic time series of the form ALERTS{alertname="<alert name>", alertstate="<pending or firing>", <additional alert labels>}. The sample value is set to 1 as long as the alert is in the indicated active (pending or firing) state, and the series is marked stale when this is no longer the case.