Research of Web QoS Control Model Based on Dynamic Resource Reallocation Scheme

At present, Web applications and HTTP requests on the Internet are so explosively increasing that a large number of hot Web sites frequently confront with problems of server overloading. And how to provide various web services with high-level quality and satisfactory performance for Web clients has become one of the most urgent points we concern. In order to smoothly solve these problems, we proposed a Web QoS control model based on dynamically reallocating resource on Web server. Facilitated by adopting reflective policy, this model could monitor the real-time state of server resources, schedule and reallocate these resources to satisfy the different client demands in practice. Moreover, this model could utilize a multiple of pre-designed policies that classify HTTP requests based on dynamic admission control scheme and distribute server resource based on dynamic resource reallocation scheme. And we conduct evaluation experiments and compare the QoS performance of this model with the basic best-effort model in IIS6.0. Evaluation results demonstrate our model could significantly reduce response time, warrant stability and reliability when requests exceed the capacity of a Web server.