Cloudflare saved 100TB of RAM by shrinking a consistent hash ring
blaizedsouza · x · 2026-09-19
Cloudflare's engineering blog details how shrinking a consistent hash ring saved roughly 100TB of RAM. The last 90,000 hashes per server only bought a 0.7% load balance improvement — math said stop, so they stopped.
The retweeter highlights two takeaways:
- At scale, even "tiny" optimizations matter enormously — these changes saved millions of dollars worth of RAM;
- The article is packed with fun CS and math: consistent hashing, the birthday paradox, storing struct fields as byte arrays, and stats — all without touching a database.
Related event: Cloudflare Saves Another 100TB of RAM by Shrinking Hash Ring(2 posts)→
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