Server-Side Persistence & Embedded Database Engines

摘要

This article describes some of the lessons that my coworkers and I learned while building Steam, a broadband platform for direct software delivery and content management, which is owned by Valve Software. Poor system or component architecture can cripple even the best database engine. We chose Windows 2000 Server as the back-end OS, partly because of our development team's experience with that platform, and partly because of I/O completion ports. This Win32 API provides a highly efficient, event-based asynchronous I/O mechanism, driving a small pool of worker threads instead of a thread-per-connection. Such a design can serve tens of thousands of connections with very little context switching. High-latency operations such as database access and cryptography do mean that you need a larger worker pool than for just a simple web server, but it is still an extremely efficient concurrency scheme.