带宽自适应的P2P网络路由协议

A Self-Adaptive Peer-to-Peer Routing Protocol

提出一种普适于各种系统环境和网络规模的结构化P2P网络协议SmartBoa.与已有的结构化P2P路由协议(如Pastry,Chord等)相比,SmartBoa结点并不维护同样大小的路由表,而是各结点根据自身的带宽能力决定其路由表的大小(最强的结点可能记录全部结点的指针,最弱的结点可能只记录其中不足1%的一小部分),算法保证路由表大小正比于维护开销,充分利用所有结点的可用带宽,使路由效率达到最优;另一方面,SmartBoa并不因为系统规模的增大而增加对结点带宽的要求,因此与全连通的one-hop overlay相比,SmartBoa可以获得更好的可扩展性;再者,SmartBoa结点根据系统环境的变化动态地调节自身级别,并且可以通过逐渐调高级别的慢启动方式来克服one-hop overlay的启动时间过长的缺陷.总之,SmartBoa是一种可以运行于任何环境,不受限于系统规模的大小、结点能力的强弱、强弱结点的比例、结点出入的频率,并通过动态调节保证路由效率的P2P路由协议,适用于各种广域分布式系统.

This paper presents a novel peer-to-peer structure overlay network SmartBoa. Compared to previous protocols, SmartBoa nodes have routing tables with different sizes, which are determined by the local nodes individually. It is ensured that the bandwidth cost of a node is proportional to its routing table size. Therefore, from the view of the whole system, all the allowable bandwidth are fully utilized to improve the routing efficiency. SmartBoa does not increase the capacity requirement for nodes when the system expands, so it can achieve higher scalability than the one-hop protocol. Furthermore, SmartBoa nodes can adjust its level at runtime, and thereby can warm up gradually when starting. This avoids the long-time initiation which is an important problem in one-hop overlay. In a word, SmartBoa is a general structure overlay network that can be deployed in any environments, not matter what the system size is, how dynamic the nodes are, and what the node-capacity distribution is like.