The Research & Realization Of The Strategies For Dynamic Load Balancing In The Parallel VOD System

With the rapid development of Internet and multimedia technologies, multimedia application over Internet walks into people's lives gradually. As an important aspect of multimedia, video application over Internet is faced with new opportunity and challenge. A lot of users request high quality service, and the server needs higher performance and efficiency. All these bring new technical issues into video applications.Bandwidth of networks and performance of video server are two main factors that restrict the utility of video applications. The video server with parallel architecture can extend the area of video service system, because it can disperse users' requests and reduce the local load of server and local traffic of networks. After analyzing the architecture and requests of video service system in detail, this paper proposes a scalable architecture of Parallel VOD System. It also describes the strategies for Dynamic Load Balance in the Parallel VOD System. Large-Scale video service system can be constructed at a low cost with this architecture.The Dynamic Load Balancing is one of the pivotal technologies in the Parallel VOD System. According to users' requests, the system can give services to them. At first, it observes the status of nodes in the system, then select one of the server nodes to serve the user using the strategy of Dynamic Load Balancing. This paper describes strategies for Dynamic Load Balancing and it puts forward three strategies, which are Circularly Allocate, Load Least First, Sorted Best First. And it gives an implementation algorithm of each strategy. SBF algorithm has applied to the Parallel VOD System efficiently as an application case. At last, it comes to a conclusion to the research and makes an expectation.