DNS build delay halved, memory use cut 85%
The gist
Cloudflare cut median DNS build delay from 7.7s to 3.3s and peak memory 85%.
Zones with tens of millions of records now rebuild far less often.
How it unfolded
- 2022Cloudflare's Zone Builder received about 250 DNS record changes per second, and per-record builds were 150 times faster than full builds on average.
- Aug 29, 2026Cloudflare cut memory used by the DNS cache behind its 1.1.1.1 resolver by more than half, freeing about 100TB of RAM through five Rust code changes.
- Nov 2, 2026Cloudflare published a blog post on a targeted build planner and new scheduler: median build delay fell from about 7.7 seconds to about 3.3 seconds, and peak memory fell from 79 GiB to 12 GiB.