Cloudflare Reclaims 100TB of RAM by Overhauling 1.1.1.1 DNS Cache
Cloudflare overhauled the 1.1.1.1 DNS cache design, rolling it out from mid-May to early July. The 99th percentile memory use per instance fell from 9.3GB to 5.3GB. With over 250B DNS entries, the redesign—fixed-size boxed slices, rebuilding names from lookup keys, and using contiguous wire-format bytes—cut A/AAAA cache footprint by 120 bytes per entry and reclaimed about 100TB of RAM.