| The Internet has grown rapidly in recent years. The developments of both bone network and local access network bring VOD applications a bright future. Since the bandwidth's needs of disk I/O and network are very immense, when facing a large amount of users, server's I/O and network's bandwidth become the bottleneck of the system. Proxy is a new technique to reduce client's start delay and network traffic, which gains a good result in the web domain. Because of very large file size and real time restrictions, traditional web proxy techniques are not suitable for streaming media applications. Video proxy techniques have to face more new challenges.This paper are based on the distributed VOD prototype system, researches in video proxy techniques, main works are as follow:Firstly, design and realize a distributed video proxy system. We adopt cluster techniques, a group of commercial PCs worked as a server to serve the clients. The proxy system has good scalability.Secondly, design and realize a segment-based caching replacement policy. It can reduce the clients' initial delay, save the consumption of network's bandwidth, at the same time decrease the original server's loads to extend.Thirdly, propose a proxy video server's load balance scheme, it based on video segmented distributed storage techniques, it can scatter disk I/O and network's loads among all the servers. This method can lead to cooperation of all the servers in the system, every proxy system can serve large quantity of users.The proxy system of this paper is a supplement to the original distributed VOD system, the system can serve even larger amount of users spreading around an even wider area than before. |
