网络规模的不断扩展和一体化承载网络的构建,产生分布式系统资源访问和分配的一致性的问题。针对数据一致性、逻辑一致性和时序一致性的问题,在分布式系统同时访问同一资源时,为了协调访问,保证访问的正确性(无死锁、无饥饿现象),设计保证一致性的互斥算法是关键问题。文章从多个系统角度来阐述保证一致性的常见算法,非基于令牌的互斥算法、基于令牌的互斥算法、选举算法和以太网的冲突检测和避免机制,以及新型网络中采用的一致性算法。
With the expanding of network scale and the constructing of Universal Carrying Network, there arise consistency problems of distributed system resource access and allocation. According to problems of data consistency, logic consistency and time consistency, in order to coordinate access, ensure validity of access (without phenomena of deadlock and starvation) ; it is a key issue to design mutual exclusion algorithm ensuring consistency. Common algorithms ensuring consistency are described from several system aspects in this paper, including non-token-ring-based mutual exclusion algorithm, token-ring-based mutual exclusion algorithm, election algorithm, Ethernet conflict detection and avoidance mechanism and consistency algorithm used in new network.