QoS-Oriented Control of Server Systems

摘要

Multi-tier architectures are widely used by internet applications. Guaranteeing the performance, and more generally the quality of service (QoS), of such applications remains a crucial issue. In this paper we propose a methodology to get the optimal admission control of multi-tier server systems under high loads for one QoS objective. First we present a model of multi-tier server systems using fluid approximations. Second, we state and solve an optimization problem which consists in finding the configuration that maximizes the availability of the system for a given performance constraint. Simulations of both model and control from this preliminary work are presented. They show that the optimal configuration of such systems is not always intuitive.