Optimization of quality of service in dynamic systems
Jeffery P. Hansen, John P. Lehoczky, R. Rajkumar · 2005
Resource allocation policies which signi cantly improve Quality of Service (QoS) while minimizing QoS instability are presented. In a dynamic system in which applications are continuously entering and departing the system, QoS instability occurs when the system over-commits resources and can not meet the resource demands of new admission requests. The system is forced to either reject the request or degrade one or more existing tasks. In this paper we introduce three admission control policies and compare their QoS performance/stability tradeo s. We show that by maintaining a small resource reserve modeled as a competing application in the QoS optimization framework, we can achieve QoS levels that are over 90% of the theoretical maximum while reducing instability by one to two orders of magnitude.