TL;DR
Five successive memory optimizations reduced Big Pineapple's per-entry DNS cache footprint from 953 to 420 bytes, freeing 100TB fleet-wide while boosting performance.
Key Points
- Per-entry memory footprint reduced 56% (953→420 bytes); production instances dropped from 9.3GB to 5.3GB at p99
- Cache insert throughput increased 43%, lookup latency dropped 19% despite aggressive memory optimization
- Freed ~100 terabytes of memory across fleet equivalent to 130 Gen 13 servers; optimizations rolled out May-July 2026
- Key techniques: Box<[T]> replacing Vec, record data as raw bytes, owner field compression, boxed enum variants
Why It Matters
This deep-dive demonstrates practical systems optimization at massive scale—250 billion cache entries—showing how careful data structure choices compound into fleet-wide savings. For engineers building high-throughput systems, the techniques (Vec→Box tradeoffs, memory layout optimization, allocator awareness) are directly applicable to any large-scale caching infrastructure.
Source: blog.cloudflare.com