Research And Implementation Of The Web Server Cluster Technologies In Virtual Environment

In recent years,people pay more and more attention to the development of virtualization technology. Today,the performance of the virtual machine is almost as much as the physical one. The IT enterprises increasingly put their Web applications on virtual machines for imporing resource utilization, imporing system reliability, imporing flexibility and reducing the costs of management. As the complexity of applications and increasing users,people have to consider building Web server clusters on virtualization platform which can avoid single points of failure and meet increasingly high performance demands. But it is hard to take advantage of virtualization technology to achieve that goal if just move the traditional Web server cluster to the virtual machines in simple way.This paper combined virtualization technologies and Web server cluster technologies conceptually and functionally,then proposes a load information collecting algorithm based on Xen server virtualization platform,designs and implements a modeling system called XCluster. By using the technology of distributed architecture,we achieved four kinds of functions,such as a load monitoring service,nodes control,task schedule and load balancing. Relying on the above functions the new model realized the comprehensive performance of cluster management. The theoretical analysis and experiment results show that the XCluster,on the one hand,can dispatch VM according to the amount of users' access request and the rest resource of hosts,on the other hand,can distribute the http requests to back-end nodes in order to achieve the purpose of load balancing.The Web server cluster which based on XCluster model make full use of the unique capabilities of the virtualization platform to management all back-end nodes in a very easy way which just need few network resources. Compared with the Cluster which using Nginx,on the high-availability aspect, there are much less failure return to client browser when some nodes become abnormal. On the performance of load balancing aspect,the active nodes' s quantized load value tend to converge as time passed,so the XCluster has better equilibrium effect. Besides,the XCluster can avoid wasting resource,yet maintaining the application's quality of service within acceptable size.