Enhancing Smart Tiered Cache for Public Cloud Regions
Cloudflare boosts cache efficiency in cloud regions.
1What is Smart Tiered Cache?
Cloudflare's Smart Tiered Cache system selects the optimal upper-tier data center for the fastest access to your site's origin server. This system works effectively when the origin IP is in a fixed location.
2The Challenge in Cloud Regions
Cloud providers' use of anycast or regional unicast networks makes the origin IP appear equally close to multiple data centers. This prevents Smart Tiered Cache from selecting a single best upper tier.
3Solution with Region Hint
Cloudflare allows users to provide a cloud region hint, enabling Smart Tiered Cache to map origins behind anycast or regional unicast networks to the correct region, improving cache efficiency.
4Enhancements for R2 and Load Balancing
In 2024 and 2025, Cloudflare extended Smart Tiered Cache for R2 storage and load balancing. These enhancements aim to better understand customer infrastructure and automatically provide the best solution.
5The Difference with Anycast Cloud Origins
Anycast cloud origins respond from multiple locations rather than a single physical point. This makes it difficult for Smart Tiered Cache to select a single best upper tier and can lead to unnecessary cross-continental traffic.
6Detecting Anycast with Physical Constraints
Cloudflare detects anycast origins using physical constraints. If latency measurements from two checkpoints are faster than the speed of light, the origin is responding from multiple locations.
7Safe Fallback Mechanism
When anycast origins are detected, Smart Tiered Cache uses multiple upper tiers instead of pinning to a single one. This maintains cache efficiency while preventing unnecessary traffic.
8Optimization with Cloud Region Hint
Cloudflare customers can provide a cloud region hint, enabling Smart Tiered Cache to select a single upper tier close to anycast origins. This enhances cache efficiency and performance.