如果指标停止出现，Prometheus警报会发生什么？

Question

I have a Prometheus alert like this:

ALERT etcdNoLeader
    IF etcd_server_has_leader{job="etcd"} == 0
    FOR 1m

What happens if the etcd_server_has_leader metric stops generating data? Does the alert fire ? Does it do anything ?

Answer 1

The alert will stop firing. You'll generally want an alert on up == 0 and depending on your setup possibly also absent(up) .