Integrating network QoS to provide Differentiated Service in a Web server

In this paper, we propose an integrated quality of service (QoS) manager (IQM) that determines and enforces the QoS given to HTTP requests that a Web server receives. In order to determine the required QoS, both the identity of the client as well as the URL being accessed should be used. To provide guarantees on round trip delay, it is not sufficient to provide QoS in the network layer or in the server alone. QoS should be monitored and enforced in both these domains and the two managers must communicate and cooperate. Web servers these days are not restricted to doling out static Web documents. The Web server executes some code for each HTTP request. This execution needs some QoS to ensure reasonable response times. The IQM is responsible for doing this. We also explore the importance of network latency in providing all-round QoS to the client. The IQM, we suggest, should be aware of network latency associated with each host and for each DiffServ marking. Based on our experiments, we outline how this marriage between network QoS and application QoS is to be done.