The VOD System Based On HDFS

As an emerging internet multi-media service, the VOD (video on demand) greatlysatisfies people’s demand on video information, so it has been widely used in many fields.The VOD system has high requirements on the storage, because the storage system is thecarrier of all the video resources and multi-media data, and storage system’s performancelargely decides the performance of VOD system. The technology of cloud storage presents anew approach to build the VOD storage system. HDFS，a cloud storage software of OpenSource, has features completely meeting the requirements of VOD system, and can savesubstantial storage device cost for users.In order to reduce VOD system cost and build a high-efficient and low-cost videoresource storage system, the paper introduces the technology of cloud storage into the VODfield, using HDFS, the distributed file system component of Open Source cloud computingsoftware Hadoop, to establish a file cluster to store the huge amount of video data of VODsystem.Starting from analyzing the storage requirement of VOD system, the paper explains thetechnological advantages of HDFS component applicable to video storage system, and putforwards a HDFS-based VOD system design plan. The plan builds a web-based VOD systemcombining the advantages of streaming media and cloud storage.The system adopts a B/S structure composed by the client side, web server, streamingmedia server and HDFS cluster. The client side offers users the VOD interface and playsvideos through the streaming media player embedded in the browser; the web server offersvideo information responding to user requests; the streaming media server makes technicalprocessing to video files responding to the users’ video play requests and sends thestreaming media data generated to the client side; the HDFS cluster is a distributed cloudstorage system composed by cheap hardware, which is responsible for storing an immenseamount of video files.The system designed in the paper has certain advantages in terms of reliability, security,expandability and economical efficiency. The system makes design combining streamingmedia technology and HDFS cloud storage technology. The streaming media technology is mature, and the HDFS technology has passed the running test of thousands of nodes and hasbeen successfully applied to many famous large systems, so the two mature and reliabletechnologies form a strong assurance for system reliability. The system designed in the paperensures the security of streaming media server, web server and HDFS cluster throughmeasures such as user identity authentication. It realizes the security of communication anddata transmission of web server, streaming media server and HDFS cluster through thesecurity mechanism of Hadoop. With the help of Hadoop’s strong expandability of storage,the system may expand the scale of HDFS cluster as needed to increase the storage ability ofvideo file. The HDFS is a distributed file system designed specially for cheap computers. Ithas a good compatibility, and computers of any type or property can join the video file storagecluster by installing the software.Testing and survey results show that the system is fully met the design goals andAchieved a better effect.