The Research And Realization Of Server Load Balancing

After the development of 34 years, the Internet has become a indispensable part of human society. Meanwhile, the network infrastructure is playing an increasingly important role in the success of a business. As the increasing demand for the network, and the expanding of enterprise's business, the company image, customer satisfaction, even the market share are all intertwined with the consistent availability of a company's web site. Therefore, the company's e-commerce site must offer a high performance, high availability, high scalability and secure network infrastructure for the applications that operate on it can offer 24 *7 services.Server Load Balancing(SLB) is a commonly used solution. As a type of one of realizing technologies of SLB, Virtual Server is a high-performance, high available, high scalable cluster of servers which appears to be only one server to an outside client.Linux Virtual Server(LVS) is a cluster system utilizing Linux's open souce code. The director of which, a router with modified routing rules, directs the client requests to the particular realserver in the cluster according to the load balance schedule. And then, the SLB is realized. Base on the reseach on the Load Balance theory, the author gives a discussion, analysis and comparison about the performance, applicability and security of the realizing method(NAT, IP Tunneling, Direct Route). Then the author describes emphatically the code-realization of the DR method.The author believes that the DR method is better than the other methods on both hand of applicability and performance. Although the security of DR method is not same as NAT-methor's, surely DR method doesn't sacrifice the system security. So, the LVS system by DR method can satisfy the demand of ordinary users.