From Chengdu COVID Testing System Crash to High‑Concurrency Architecture: Lessons for Backend Engineers
The article examines the Chengdu COVID‑19 testing system failure, analyzes its root causes such as oversized MySQL tables and insufficient load handling, and then presents a step‑by‑step high‑concurrency roadmap—including single‑machine, service‑database separation, caching, load balancing, read/write splitting, sharding, hardware and DNS load balancing—to help backend developers design scalable systems.
