How to fix DNS service high CPU usage, kube-dns consuming CPU in Kubernetes

KubernetesINTERMEDIATEMEDIUM

DNS service overloaded causing high CPU usage. Fix by scaling DNS pods, tuning cache settings, or switching to CoreDNS.

What this error means

The DNS service (kube-dns with dnsmasq or CoreDNS) becomes a bottleneck when handling high query rates or misconfigured DNS policies.

1Check DNS pod CPU

bash

kubectl top pod -n kube-system -l k8s-app=kube-dns

2Scale DNS replicas

bash

kubectl scale deployment kube-dns --replicas=3 -n kube-system

3Increase DNS pod resources

bash

kubectl edit deployment kube-dns -n kube-system
# Increase CPU requests and limits

4Switch to CoreDNS

CoreDNS is more efficient than kube-dns.

CoreDNS supports concurrency much better than dnsmasq.