CoreDNS exposes health metrics such as resolution results through the standard Prometheus API to detect exceptions on the CoreDNS server or even upstream DNS server.
Port for obtaining coredns metrics. The default zone listening IP address is {$POD_IP}:9153. Retain the default value. Otherwise, Prometheus cannot collect the metrics.
If you use on-premises Prometheus to monitor Kubernetes clusters, you can observe related metrics on Prometheus and configure alarms for the key metrics. For details, see prometheus.

Monitoring the coredns Add-on