CoreDNS · Rate Limits

Coredns Rate Limits

CoreDNS is a self-hosted DNS server. It does not expose a public hosted API with provider-imposed per-second request limits. The HTTP Health (port 8080) and Prometheus Metrics (port 9153) endpoints are intended for in-cluster operations and have no upstream-imposed rate limit; effective limits are bounded by the operator's deployment topology and node CPU. CoreDNS does, however, ship plugins (ratelimit, bufsize, cache) that operators can configure to throttle DNS query throughput.

Coredns Rate Limits is the machine-readable rate-limit profile for CoreDNS on the APIs.io network, conforming to the API Commons Rate Limits specification.

It captures 3 rate-limit definitions, measuring queries_per_second and requests_per_second.

The profile also includes 3 backoff/retry policies defined.

Tagged areas include Cloud Native, DNS, Kubernetes, Networking, and Open Source.

3 Limits
Cloud NativeDNSKubernetesNetworkingOpen SourceService DiscoveryRate Limiting

Limits

DNS query rate deployment
queries_per_second
operator-configured
Bounded by node CPU and configured via the optional ratelimit plugin. No upstream-imposed number.
Health endpoint deployment
requests_per_second
not enforced
HTTP /health on port 8080 is intended for kubelet liveness/readiness probes; CoreDNS does not throttle it.
Metrics endpoint deployment
requests_per_second
not enforced
HTTP /metrics on port 9153 is intended for Prometheus scraping; CoreDNS does not throttle it.

Policies

Operator-configured throttling
Use the ratelimit plugin (external) to apply per-source rate limits to DNS queries. Configure cache and bufsize plugins to absorb bursts and reduce upstream load.
No hosted API
CoreDNS is run by the operator inside their cluster or environment. There is no provider-hosted DNS endpoint and therefore no provider-imposed rate limit.
Backoff for clients
DNS clients should respect SERVFAIL and REFUSED responses and back off rather than hot-looping; the cache plugin can be tuned to reduce load when SERVFAIL spikes.

Sources