Performance modeling of an Apache web server with bursty arrival traffic

Abstract

Performance modeling is an important topic in capacity planning and overload control for web servers. We present a queueing model of an Apache web server that uses bursty arrival traffic. The arrivals of HTTP requests is assumed to be a Markov Modulated Poisson Process and the service discipline of the server is processor sharing. The total number of requests that can be processed at one time is limited to K. We obtain web server performance metrics such as average response time, throughput and blocking probability by simulations. Compared to other models, our model is conceptually simple. The model has been validated through measurements and simulations in our lab. The performance metrics predicted by the model fit well to the experimental outcome.