High Concurrency

← Series hub Next → Chapter 1: Overcoming the C10M Barrier To build a system capable of handling millions of Requests Per Second (RPS) — known as the C10M problem — vertical scaling is never enough. It requires a meticulously designed Distributed Architecture. 1. The Shift from C10K to C10M Answer-first: While C10K was solved by non-blocking I/O (like NGINX), C10M shifts the bottleneck to the OS kernel. Systems must bypass the kernel using DPDK or XDP to handle 10 million connections efficiently. ...

Answer-first: How Shopee engineers prevent crashes during 11.11 flash sales: rate limiting, Redis inventory locks, traffic shields, and microservices resilience. At exactly midnight on 11.11, Shopee users across Southeast Asia and Taiwan simultaneously tap the same button. In the first 10 seconds of a flash sale, a single product page can receive requests from millions of concurrent sessions — all competing to purchase the same 1,000 units of inventory. One oversell, one server crash, or one database deadlock during that window results in a cascade of chargebacks, angry users, and front-page news headlines. ...