Shedding old code with ecdysis: graceful restarts for Rust services at Cloudflare

Cloudflare announces and explains ecdysis, an open-sourced Rust library that enables zero-downtime, graceful restarts for network services using a fork-then-exec model with inherited listening sockets, ensuring no dropped or refused connections during upgrades. The post outlines why naive restarts fail, how ecdysis coordinates parent/child readiness and draining, its Tokio and systemd integrations, security considerations (explicit FD inheritance, CLOEXEC, seccomp compatibility), a simplified echo-server example, and how it compares to Cloudflare’s tableflip (Go) and shellflip (Rust) alternatives, noting its proven production use across Cloudflare’s global network.