specification: API Commons Rate Limits
specificationVersion: '0.1'
schema: https://raw.githubusercontent.com/api-evangelist/interface-research/main/schema/api-commons.yml#/$defs/RateLimits
provider: CoreDNS
providerId: coredns
created: '2026-05-04'
# Provenance stamped 2026-08-11: this artifact was written by the API Evangelist
# bulk sweep dated 2026-05-04, not harvested from the provider. See roadmap#35.
method: generated
modified: '2026-05-05'
reconciled: false
tags:
  - Cloud Native
  - DNS
  - Kubernetes
  - Networking
  - Open Source
  - Service Discovery
  - Rate Limiting
description: 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.
sources:
  - https://coredns.io/manual/toc/
  - https://coredns.io/explugins/ratelimit/
  - https://coredns.io/plugins/cache/
limits:
  - name: DNS query rate
    scope: deployment
    metric: queries_per_second
    limit: operator-configured
    notes: Bounded by node CPU and configured via the optional ratelimit plugin. No upstream-imposed
      number.
  - name: Health endpoint
    scope: deployment
    metric: requests_per_second
    limit: not enforced
    notes: HTTP /health on port 8080 is intended for kubelet liveness/readiness probes; CoreDNS does
      not throttle it.
  - name: Metrics endpoint
    scope: deployment
    metric: requests_per_second
    limit: not enforced
    notes: HTTP /metrics on port 9153 is intended for Prometheus scraping; CoreDNS does not throttle
      it.
policies:
  - name: Operator-configured throttling
    description: 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.
  - name: No hosted API
    description: 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.
  - name: Backoff for clients
    description: 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.
notes: CoreDNS is open-source and self-hosted, so there is no provider-imposed rate limit. Reconciled
  is false because there is no provider rate-limit document to reconcile against; this artifact captures
  the rate-limiting capabilities CoreDNS exposes to operators rather than limits applied to a hosted
  CoreDNS API.
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com