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CDN Service — Notes#

This is the commercial CDN product view (Cloudflare / Fastly / Akamai / CloudFront). For the underlying mental model see 00-fundamentals/cdn.

Functional#

  • Reverse-proxy customer origins.
  • Edge caching (rules, TTLs, surrogate keys).
  • WAF + bot management.
  • TLS termination, certificate management (ACME).
  • Edge compute (Workers / Lambda@Edge / Compute@Edge).
  • DDoS mitigation.
  • Real-time analytics & logs.
  • Origin shielding.

Non-functional#

  • 99.99%+ availability.
  • p99 hit < 50 ms regional, < 100 ms global.
  • Tbps of aggregate egress.

Capacity#

  • Hundreds of POPs.
  • Multi-PB working set across edge.
  • 10M+ rules / configurations.

API#

  • Customer API for purge, config update, certificates.
  • Webhooks / events for invalidation success, attack alerts.

Trade-offs#

  • POP density vs operational cost.
  • Edge compute flexibility vs caching simplicity.
  • WAF false positives are a customer support nightmare — tune.

Refs#

  • Cloudflare / Fastly / Akamai engineering blogs.
  • AWS CloudFront, GCP Cloud CDN docs.
  • "How CDNs work" Cloudflare learning center.