How we halved DNS build delay and cut memory use by 85%
- ID
- 41966
- Status
- summarized
- Published
- 02 Nov 2026, 10:00 PM
- Fetched
- 02 Nov 2026, 10:18 PM
- Provider
- Cloudflare Blog
- Category
- infrastructure
- Original URL
- https://blog.cloudflare.com/dns-targeted-zone-builds/
- Source URL
- https://blog.cloudflare.com/rss/
Summary
- Score
- 6.5
- Created
- 02 Nov 2026, 10:19 PM
- Tags
- Audience
- developerssaas_founders
What happened
Cloudflare's Zone Builder now handles about 700 DNS record changes per second, up from 250 in 2022, with some zones exceeding 20 million records. The team built a targeted build planner that chooses the smallest provably safe build and a scheduler that combines same-zone work, so zone-setting changes no longer rebuild huge zones. This cut peak memory by 85% and halved the time from a DNS change to data being written to Quicksilver.
Why it matters
If you operate multi-tenant DNS or config pipelines, the concrete lesson is to avoid full-zone rebuilds for zone-level setting changes when zones reach millions of records: Cloudflare's planner proves the smallest safe build and merges same-zone work, yielding 85% lower peak memory and half the write delay. Cloudflare customers may also see faster propagation after settings changes, but the post does not give a new public SLA.
Discussion angle
How do you safely choose the smallest rebuild when an event does not say what changed, especially when zone settings can affect multiple zones with the same name?