What causes "DNS_HIGH_CPU"?

Excessive DNS queries from pods Single-threaded dnsmasq hitting CPU limit Missing DNS caching in applications

Is the "DNS_HIGH_CPU" error serious?

It is a medium-severity error — more of a blocker than a risk. The steps above resolve it.

KubernetesINTERMEDIATEMEDIUMUpdated Dec 6, 2025· 94 views

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

Fixes DNS_HIGH_CPU

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

kubernetes — error

$kubectl top pod -n kube-system -l k8s-app=kube-dns
DNS service high CPU usage, kube-dns consuming CPU

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.

5Monitor DNS performance

Track query rates and latency.

CoreDNS supports concurrency much better than dnsmasq.

What does "DNS_HIGH_CPU" mean?: The DNS service (kube-dns with dnsmasq or CoreDNS) becomes a bottleneck when handling high query rates or misconfigured DNS policies.
How do I fix "DNS_HIGH_CPU"?: DNS service overloaded causing high CPU usage. Fix by scaling DNS pods, tuning cache settings, or switching to CoreDNS.
What causes "DNS_HIGH_CPU"?: Excessive DNS queries from pods Single-threaded dnsmasq hitting CPU limit Missing DNS caching in applications
Is the "DNS_HIGH_CPU" error serious?: It is a medium-severity error — more of a blocker than a risk. The steps above resolve it.