The Design And Implementation Of Source Server And Real-Time Monitor In A P2P-VoD System

In recent years, online video service develops quickly. It has become one of the main Internet applications. Especially in China, watching online videos has become the secondary popular behavior among Chinese Internet users. As one of the main online video services, VoD has a wide range of users. With the increase in the number of users, the content delivery model based on traditional C/S mode makes the Source Server a bottleneck for providing large-scale VoD services. P2P mode breaks the traditional C/S mode, gives each node both server and client roles, makes full use of nodes’idle storage resources and uplink bandwidth to deliver data. It improves the sharing and utilization rates of resources, and avoids congestion and bottlenecks. Due to its advantages in scalability, robustness, low cost, high performance, P2P technology becomes a key technology in providing large-scale VoD services and is widely used in popular VoD systems.With the maturity of adopting P2P technology, the presure on Source Server is eased. However, the Source Server is still the bottleneck of the entire system. On the one hand, user requirements for higher quality videos give the Source Server an increasing burden. On the other hand, in a typical VoD scenario, a new coming hot channel will be visited by a large number of users in a short time. In this period of time, the P2P technology cannot share the traffic for the servers effectively; the performance of Source Server still affects user experience directly. So, the design of a high performance Source Server is still a very important part of overall system design. Besides, in actual operation of a VoD system, a variety of data need real-time monitoring. Collection, statistic and analysis of these data are also needed for mining meaningful information from to evaluate and improve the VoD system. So, the design and implementation of a real-time monitor is also of great significance.This paper firstly introduces the development status, key technologies, and challenges of current P2P-VOD systems. New technologies in current P2P-VOD systems are also tracked. Secondly, this paper describes the overall structure and functions of each module in a prototype P2P-VOD system named "PPlayer". This paper also design and implement the Source Server and Real-time Monitor. Finally, several tests and an operation experiment are conducted. The availability of PPlayer VOD system is proved by functional verification. The improvements and deficiencies of the Source Server are analyzed in performance tests. The meaningful data are gained from the operation experiment by the Real-time Monitor. The evaluation and analysis of system performance and user behaviors are carried out based on these data.