Research On Caching Strategy In Client Based On A VOD System On P2P

How to actualize resource storage and location effectively while the systematic entirety is kept is an important problem that requires to be solved in peer to peer video on demand. In server, proxy server and client of peer to peer video to demand, cache technology plays an important role on aspects of relieving network transmission pressure, balancing overall load, and reducing network bandwidth consumption. Design and selection of caching strategies can improve system performance.This paper focuses on the new cache replacement policy that is fit for client and is proposed towards the fact that few researches on client cache technology have been made and is based on the video on demand with server structure P2P network environment. Later, this paper proposes the model of this strategy, elaborates the model, and analyze its advantages and disadvantages. Double predictive caching model is composed of four cache queries, three more than the traditional video on demand, aiming at increasing hit ratio of cache through caching more valuable streaming data, and then promoting system performance. Then, this paper makes a research on double predictive caching replacement algorithm, which has solved the problems such as cached copy distribution, cached copy probabilistic consistency and selection of threshold. Then, this paper also makes a deep discussion on the problem of data scheduling in cache, puts forward the data substitutions and scheduling algorithms of different caches, and also proposes the solutions for the data scheduling resulted from cache scheduling and VCR operation.In order to analyze and compare the advantages and disadvantages of double predictive caching model proposed in this paper and the model in traditional video on demand, and to prove the feasibility and correctness of this model, this paper develops a simulator which is fit for both double predictive caching model and traditional cache model by using of VC based on the analysis of traditional simulator. This paper analyses the system structure of simulator firstly, gives a detailed description of actualization of each module and also makes an explanation of setting up of required parameter. Finally, the use of the stimulator has proved that the double predictive caching model proposed in this paper is capable of increasing order probability of inner data, effectively shortening time of VCR operation and promoting QoS of video on demand when the number of people who order is increased gradually.