P2P流媒体系统缓存及调度策略研究

1、西北大学硕士学位论文p2p流媒体系统缓存及调度策略研究姓名：王文波中请学位级别：硕士专业：计算机软件与理论指导教师：范训礼20090618摘要近年来，采用p2p模式解决流媒体服务系统的瓶颈问题受到越来越多的重视。如何 在充分利用p2p网络中众多节点资源的前提下,确保流媒体服务质量、提髙播放的性能, 成为p2p流媒体技术研究的热点。本文窪分祈祁总结规有瞬舷傩腹缺昭牺脚掏軸w灘谢俸汰流媒体点 播系统左鮒能的楸册w1谕行胡研究主空要隹俺如下:首先，耒文獅郦納扇鞠柿朋豌鏈迟攔紘逢縷度服眾删嘶能的庄要因素，论述了节点缓存管理和数据调度策略对p2p流媒体性能优化的重要作用。其次，本袞枫擁将绸瞬指細融行孤深

2、椒研究从凍疯媒伽沁歸繚餐的 要求、缓存兗间的用法翻面盼浙t嚨廖商管理枫制的优点饼钿删删率瞬管 理机制中缓存替换策略的不足，删何麴的基予畴供需善1、删鐵馳度的礙趣替换策略。随后，在分析、归纳目前研究工作基础上，针对现有数据调度策略的不足，提出了 新的基于播放缓存偏移量的sscop调度策略，并对该策略在概率缓存管理机制中的使 用方法进行了描述。最后，对采用了 sddu替换策略和sscop调度策略的新概率缓存管理机制进行了模拟实it通过自辭昨缓褂鲫觑刪命島动延迟播播瞬镰孰磁關疑歸歿能方 面的比较” iffi颂徼越廠繼蓟熔競统要餒性能起到丽忧瞬用。关键词：p2p流媒体，概率缓存机制，缓存替换策略，数据

3、调度策略abstractin kficent years, the research on eliminating the bottleneck of the streaming media service bf p2p system has baaome a hotspot in the application field. moreover, how |o guarantee the quality of service of streaming media and promote the system performance on the premise of 応iqg full adv

4、antage of the resources of many nodes in the p2p network is one important ttpect in the field.based on analyzing and summarizing system architecture and the application characteristics of the existing p2p streaming media system, this paper studies the optimization of the performance of the p2p on-de

5、mand streaming media system. the details are as following:first qf all, the paper analyzes and 购梢marizes the main factors that affecting the node startup-latency, playback continuity, and the smer load performances. the paper also digfiourses the important effects of node caching jgement andstrategy

6、 onthe會f p2p streaming system.swmdly, the paper studies the existing caching 脚備俩晰&映鶴atingly. meanwhile, the paper aamyzes the advantages of the probability caching mechanism from the views of the streaming media demanding of buffer management and the usage bf jwa触 m彌ory space. moreover, in order

7、 xo overcome theof cache replacement strategy of the existingprobability caching mechanism, a novel strategy based on the/gypply-demanddifference and urgency, which is called sddu strategy, is proposed xo further improve the 倆諏m诫 mgs.subsequently, to overcome the drawback of the existing data schedu

8、ling strategy, the paper proposed a novel data scheduling 曲which is based on the cache flififset of playback and called sscop. after that, the paper describes how to use the new strategy in the probability caching mechanism.finally, the new probability caching management mechanism using sscop and sd

9、du strategies is simulated in a simulator. in the simulation, the existing probability caching 脚同gement mechanism is also simulated with the same parameters. through comparing the new with the old in startup-latency, playback 恥瞞欣aity, and the server load, the paper confirms that the improved probabi

10、lity caching management mechanism can effectively promote these main performances.key 盹o御s: p2p 磁弈祀gfrobability caching management mechanism, cachereplacement strategy, data scheduling strategy西北大学学位论文知识产权声明书本人完全了解西北大学关于收集.保存、使用学位论文的规定。 学校有权保留并向国家有关部门或机构送交论文的复印件和电子版。 本人允许论文被查阅和借阅。本人授权西北大学可以将本学位论文的 全部或部分内容编入有关数据库进行检索，可以采用影印、缩印或扫描等复制手段保存和汇编本学位论文。同时授权中国科学技术信息研 究所等机构将本学位论文收录到中国学位论文全文数据库或其它 相关数据库。保密论文待解密后适用本声明。学位论文作者签名庄交皮2009年5月必日2009年月徊西北大学学位论文独创性声明本人声明：所呈交的学位论文