Cloudflare Improves Smart Tiered Cache for Public Cloud Regions

Cloudflare's Smart Tiered Cache, launched in 2021, picks the single best upper-tier data center for each origin based on real-time latency measurements. That approach breaks down for origins hosted on public clouds like AWS, GCP, Azure, and Oracle Cloud, which typically sit behind anycast or regional unicast front ends — making a single IP appear equally close to many Cloudflare data centers and preventing a clear winner from being chosen. This often caused cross-continental 'hairpin' traffic and lower cache hit ratios.

Cloudflare previously mitigated this by detecting anycast origins using a speed-of-light latency check across multiple checkpoints, falling back safely to multiple upper tiers when detected — a safe but less efficient outcome. The new Smart Tiered Cache for Public Cloud Regions feature lets customers supply a cloud region hint (e.g., aws:us-east-1) per origin IP. Cloudflare matches this against regularly updated cloud provider IP-range files and continuously refreshed latency probe data to determine a primary upper tier and a fallback from a different PoP for each region.

For engineers, this translates into better cache efficiency, fewer origin connections, and reduced latency for cloud-hosted origins behind anycast IPs. Region hints can be configured individually or in bulk via the dashboard, API, or Terraform. When a region lacks sufficient probe data, the system temporarily falls back to the nearest Tier 1 PoP geographically, transitioning to data-backed selection as probes accumulate.