HOW WE COULD SAVE PETABYTES OF CACHE STORAGE WITH ZSTANDARD AND PINGORA

Summary from the TLDR DevOps newsletter

Cloudflare has prototyped a system called Cache Transcoding that compresses eligible cached assets using the Zstandard algorithm before writing them to disk, shrinking those assets to roughly one-third of their original size on average. The system targets compressible text content like HTML, JSON, CSS, and JavaScript, which made up 67.3% of requests in Cloudflare's traffic sample but arrived uncompressed about 71% of the time. Encoding happens once when an asset enters the cache, while the CPU cost of decoding is paid on every serve at approximately 1.56 nanoseconds per byte. In testing across 10 cache servers with more than a million requests, the architecture stayed within its CPU budget at zstd level 3 with a 4 kibibyte minimum object size.