提高冗余服务性能的动态容错算法

针对分布式应用的性能要求,引入了负载平衡机制，以便对activere plication和primary backup容错算法进行权衡.提出一种基于冗余服务的动态容错算法RAWA(read-any-write-any),能根据系统负载状况动态改变请求的quorum,不但提高了请求的处理速度,而且以一种简单、有效的方式实现了负载平衡.结合所提出的一致性维护和互斥访问机制,该算法可以适用于嵌套访问和状态服务.另外，还分析了RAWA算法的性能,并通过在CORBA平台上与其他容错算法的对比测试,证明RAWA算法在

A Dynamic Fault Tolerant Algorithm for Improving Performance of Redundant Services

According to the performance requirements of distributed applications, the load balancing is introduced into fault tolerance in this paper to reach tradeoff between active replication algorithm and primary backup algorithm. A dynamic fault tolerant algorithm RAWA (read-any-write-any) is presented in the paper for redundant servers to dynamically change quorum with variability of system load. It not only improves the processing speed of requests, but also implements load balancing in a more efficient and simplier way. Integrated with consistency and mutual mutual visiting mechanisms, RAWA algorithm can be applied to stateful servers and nested visting. The performance of RAWA algorithm is also analyzed, and through experiments on CORBA platform, the comparisons with other fault tolerant algorithms indicate that RAWA has effectively improved the performance of redundant servers without damaging system availability.