Proactive Serving Decreases User Delay Exponentially

Abstract

In online service systems, the delay experienced by a user from the service request to the service completion is one of the most critical performance metrics. To improve user delay experience, recent industrial practice suggests a modern system design mechanism: proactive serving, where the system predicts future user requests and allocates its capacity to serve these upcoming requests proactively. In this paper, we investigate the fundamentals of proactive serving from a theoretical perspective. In particular, we show that proactive serving decreases average delay exponentially (as a function of the prediction window size). Our results provide theoretical foundations for proactive serving and shed light on its application in practical systems.