Cloudflare frees up 100TB of RAM by shrinking 1.1.1.1's DNS cache entries — 250 billion cached DNS entries at any given time means one wasted byte costs 250GB
- ID
- 19041
- Status
- summarized
- Published
- 28 Aug 2026, 9:14 PM
- Fetched
- 28 Aug 2026, 9:37 PM
- Provider
- Tom's Hardware
- Category
- technology
- Original URL
- https://www.tomshardware.com/tech-industry/big-tech/cloudflare-frees-100tb-of-ram-by-shrinking-dns-cache-entries
- Source URL
- https://www.tomshardware.com/feeds/all
Summary
- Score
- 6.5
- Created
- 28 Aug 2026, 9:38 PM
- Tags
- Audience
- developersdatabase_learners
What happened
Cloudflare optimized the DNS cache entries for its 1.1.1.1 resolver to reclaim 100TB of RAM. With 250 billion entries cached at any given time, a single wasted byte per entry translates to 250GB of wasted memory, making byte-level data structure optimization critical at that scale.
Why it matters
If you run any caching layer at scale, this is a concrete reminder that data structure field sizing matters disproportionately—audit your cache entry layouts for wasted bytes before throwing more RAM at the problem. The math (250B entries × 1 byte = 250GB) is a useful back-of-envelope model for justifying struct-packing work on your own hot-path caches.
Discussion angle
How to calculate whether your own cache or in-memory store is large enough that byte-level struct optimization beats the engineering cost of doing it—using Cloudflare's 250B-entry threshold as a reference point.