Explicitly Controlling the Fair Service for Busy Web Servers

There is a growing demand for Web applications to provide fair service to the highly concurrent requests. In this paper, we present an approach to addressing this requirement. Based on the staged event-driven architecture (SEDA), our design takes advantage of global control strategy to balance the loadings across the staged network, makes use of system identification to automatically model performance, and applies control theory to automatically control performance fairness. By implementing our design on a Web server and evaluating the performance with unpredictable dynamic loadings, we demonstrate that our design is able to yield superior performance on fairness, showing high accuracy and good robustness.