Design And Implementation Of VOD Information System Based On GRID

The common VOD system has some weaknesses such as limit of storage capacity, performance of I/O and processor of server, choke point of network bandwidth, and problem of fake media-link etc. To avoid the problems mentioned above, we designed a blue print which is called GRID-VOD, and made it true. The main ideas of the blue print are: integrating several alone-VOD to a whole VOD system, and using the GRID technology to control it.The GRID-VOD System is based on Globus - a kind of middle-ware of GRID technology. With GRID technology, we build a VO (Virtual Organization) which is composed of many distributed nodes such as pc, server and cluster and so on. In the GRID-VOD, one of the key points is how to get the information from each different node, and how to integrate the information. With the IS (Information Service) and GSI (Grid Security Infrastructure) which are both function components in Globus, we achieve the goal. And we build a portal to provide an interface which is between GRID-VOD and users. The GRID-VOD can get the dynamic information of each node in VO, so the system knows which VOD Server is running, what multi-media files there are in each node, what performance of I/O or CPU of every node is, and the information of network bandwidth etc. By processing the information, the GRID-VOD can provide some main functions: A. Unique View: from the portal provided by the system, user can get the items of multimedia which are different from each other; B. Load Balancing: When one user clicks a media-link through Portal, the system receives the request, and then it selects a fit VOD server in GRID to build the link between the user and the node through portal. Because of the decentralization of service requests from user, the load of the whole GRID-VOD system is balanced. Otherwise, the IS of Globus lacks the support to information storing in Chinese, and we gives two different ways to resolving this problem.