Cloudflare slashes 1.1.1.1 DNS cache memory use and speeds up queries
A leaner cache layout frees about 100 TB of RAM and makes Cloudflare’s 1.1.1.1 resolver faster under load.
Cloudflare has redesigned the DNS cache representation in its 1.1.1.1 resolver, cutting per-entry memory use by more than half and freeing about 100 TB of RAM across its infrastructure. The team implemented five Rust-level layout changes in Big Pineapple, including replacing heap vectors and strings with boxed slices, unifying record lists, packing flags, and reconstructing some names from cache keys. A later redesign moved DNS records into a single contiguous wire-format buffer to eliminate enum and per-record allocation overhead and to improve cache locality. Benchmarks show the new design substantially reduces bytes and allocations per cache entry while boosting insertion throughput by 43% and reducing lookup latency by 19%. The rollout, completed between May 18 and July 6, 2026, lowered p99 memory per instance from 9.3 GB to 5.3 GB and p90 from 6.5 GB to 3.8 GB, allowing Cloudflare to grow cache capacity without adding RAM.
Why it matters
Running a global resolver with over 250 billion cached entries at once means even small per-entry savings translate into large infrastructure changes. By cutting each entry’s memory footprint by 56% and freeing about 100 TB of RAM across its fleet, Cloudflare can hold more DNS data in memory while also improving performance. The new layout boosts insertion throughput by 43% and trims lookup latency by 19%, so users and applications hitting 1.1.1.1 should see faster, more responsive DNS resolution as the cache scales.
Signal or noise?
Does this story matter, or is it hype? Decide before you see what everyone else thinks.
Sources
- InfoQ