The Study On Web Server Cluster And The Design And Implementation Of Two Level Load Balance

With the rapid growth of the computing technology and network, Web service is widely used in the commercial fields and is becoming a popular way of sharing information. And the same time, facing the highly scalable, available and high performance requirements on web service, a computer doesn't satisfy them any more. Therefore, server cluster technology is need, which composes of a group of servers interconnected into a whole through high-speed network to provide web service like a single system image.In this thesis, we firstly discuss web load characteristics, the definition, key issues and technology strategies of web server cluster, and analyze all kinds of existing solutions. Then we present the layers of ideal web server cluster architecture and a new architecture. Besides, based on the analysis of traditional load balancing methods we introduce the design and implementation of two levels load balancing of the new web server cluster. Due to the load balancing method, the web server cluster is highly scalable, available and high performance, and can also support heterogenous environments.In the thesis, we also introduce the self-similar property of modern network traffic and discuss its effects on the system's behavior and performance. Base on these studies, we implement a performance test for the load balancing schemes. At the end of the paper, summary and successive work are given.