GoKawiilCloudflare halves DNS cache memory, freeing 100TB across 1.1.1.1 network
Cloudflare reworked the Rust codebase powering its Big Pineapple DNS caching system, shrinking the average cache entry from 953 bytes to 420 bytes without adding any hardware. The changes—including replacing growable Vec and String types with fixed-size boxed slices and consolidating record storage into a single buffer—cut per-instance memory use from 9.3GB to 5.3GB while also boosting insert speed and lowering lookup latency.
GoKawiil's interpretation of the reporting above, not reported fact.
With Big Pineapple holding over 250 billion DNS entries at once, even single-byte inefficiencies multiply into hundreds of gigabytes across Cloudflare's fleet, so software-level optimization can rival the impact of buying new hardware. The improvements also make the 1.1.1.1 resolver and related DNS services faster and cheaper to run at massive scale, a model other infrastructure providers may look to replicate.
- Cache entry size dropped from 953 bytes to 420 bytes via Rust code changes, not new servers.
- Insert throughput rose to 893,000 entries/sec and lookup latency fell to 670 nanoseconds.
- Switching Vec/String types to fixed-size boxed slices alone saved over 15TB of RAM fleet-wide.
Programming Rust (O'Reilly, 2nd Edition) — Cloudflare's 100TB memory win came from careful Rust data-structure work, and this O'Reilly guide is the go-to deep dive into exactly that kind of low-level memory control and performance tuning. If reading about shrinking a cache entry from 953 to 420 bytes made you curious, it's a great way to learn how ownership, layout, and zero-cost abstractions actually work in practice.
See Programming Rust (O'Reilly, 2nd Edition) on Amazon → Affiliate link — we may earn a commission on purchases, at no extra cost to you. Product picked by AI based on this article; it is not a tested recommendation.Source: techspot.com — Skye Jacobs, 2026-08-29
Published there as: “Cloudflare freed up 100TB of RAM behind its 1.1.1.1 DNS without adding a single server”
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