基于时间间隔的P2P流媒体直播系统缓存算法

P2P streaming media broadcast system caching algorithm based on time-interval

针对基于分片传输机制的P2P流媒体直播系统客户端缓存问题,为提高节点间请求数据分片的命中率和避免数据分片大量冗余,提出一种依赖邻居节点请求量的节点缓存替换算法。该算法将分片在节点的缓存时间进行等间隔划分,利用马尔可夫链转移概率矩阵计算理论,预测分片在下一时刻的缓存价值。并将该算法和传统算法FIFO及LRU算法进行了对比实验,实验结果表明,在同等条件下,该算法相较于传统算法能更好地提高数据的命中率。

In the P2P streaming media broadcasting system based on the data transferring in piece, peer＇s cache have some problems such as the hitting ratio of data requests between the neighbor nodes and large number of redundant data slicing. A caching replacement algorithm based on the request number of the neighbor peers is proposed. This algorithm divides the caching time of each data into even interval. With the theory of Markovian status transfer probability matrix, the cache value of each data piece in next time intervals could be forecasted. The paper gives the comparative experiments among this algorithm, LRU and FIFO. According to the result of the simulation, this algorithm excels the traditional algorithm in the hitting of data requesting under the same condition.