Adaptive Disk Scheduling Algorithms for Video Servers

Soft-real time applications, such as continuous media (CM) systems, have an important property, namely, they allow for graceful adaptation of the application Quality-of-Service (QoS), and therefore are able to have acceptable performance with reduced resource utilization. This can be used by the admission control process to decide if an application can be admitted, even if the resource is congested. In this paper, we present a Soft-QoS framework for Continuous Media servers, which provides a dynamic and adaptive admission control and scheduling algorithm. Using our policy, we could increase the number of simultaneously running clients that could be supported and could ensure agood response ratio and better resource utilization under heavy tra c requirements. The observations and ndings from the model are validated with simulation studies