Caching the uncacheable: CloudFlare's Railgun

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Introduced Railgun, a premium service for Cloudflare Business and Enterprise customers, designed to cache uncacheable content. Railgun works by recognizing that dynamically generated pages change slowly and uses a delta-compression technique, similar to video compression, to send only the differences between page versions. It consists of sender (in Cloudflare data centers) and listener (on customer networks) components that establish a permanent, TLS-secured TCP connection. This connection uses a binary multiplexing protocol to run multiple HTTP requests simultaneously. When a new request for a page is received, the sender compares it to the last seen version, sends the differences across the link, and reconstructs the page. This method significantly outperforms standard Gzip compression, achieving compression ratios as low as 0.29% for small page changes.