KubeAPIDown alert is triggered when all Kubernetes API servers have not
been reachable by the monitoring system for more than 15 minutes.
This is a critical alert. The Kubernetes API is not responding. The cluster may partially or fully non-functional.
Check the status of the API server targets in the Prometheus UI.
Then, confirm whether the API is also unresponsive for you:
$ kubectl cluster-info
If you can still reach the API server, there may be a network issue between the Prometheus instances and the API server pods. Check the status of the API server pods.
$ kubectl -n kube-system get pods $ kubectl -n kube-system logs -l 'app=kube-apiserver'
If you can still reach the API server intermittently, you may be able treat this like any other failing deployment. If not, it’s possible you may have to refer to the disaster recovery documentation.