关键词: 分布式系统，层次式，失效检测，检测算法

Abstract: Aiming at the problem of the accuracy and efficiency of hierarchical failure detection method in distributed systems, this paper proposed an improved algorithm of hierarchical failure detection in distributed systems based on Chen prediction algorithm, which is on guidance of hierarchical failure detection mechanism of the o均ect level, process level and host level. In distributed systems, the traditional hierarchical failure detection method always encounters problems such as single point failure, detection delay and so on. hhcy proposed that detection messages in local area network are limited within the group when layering, and different nodes of one group assume different detection among groups.A trust variable and a correction scale factor are added in improved algorithm. In order to increase network delay,increasing the load of network is adopted for simulating the complexity of largcscale networks. Then, the experimental verification of the algorithm is completed. The experimental results demonstrate that the accuracy and efficiency of fai lure detection are improved and misdiagnosis rate is reduced by adopting the improved algorithm They offer research base for further optimization of failure detection methods.

Key words: Distributed systems, Hicrarchical,Failure detection, Detection algorithm