Using accept() Strategies to Improve Server Performance

This thesis evaluates techniques for improving the performance of three architecturally different web servers. We study strategies for effectively accepting incoming connections under conditions of high load. The experimental evaluation shows that the method used to accept new connection requests can significantly impact server performance. By modifying each server’s accept strategy, we improve the performance of the kernel-mode TUX server, the multi-threaded Knot server and the event-driven μserver. Under two different workloads, we improve the throughput of these servers by as much as 10% – 39% for TUX, 0% – 32% for Knot, and 39% – 71% for the μserver. This thesis provides and in-depth look at these results, including analysis of throughput, queue drops, response times, and other server statistics. Interestingly, the performance improvements realized by the user-mode μserver allow it to obtain performance that rivals that of an unmodified TUX server.