基于随机Petri网的冗余备份系统可信赖性研究

Study on Dependability of Redundant Standby System Based on Stochastic Petri Nets

可信赖性的度量能客观反映冗余备份系统的可信性,是评价冗余系统服务能力的主要准则。随机Petri网(SPN)对系统的并发性、异步性和不确定性具有很强的动态分析能力,特别适合系统建模和可信赖性分析。讨论了冗余备份系统的概念及其随机Petri网描述,采用SPN对冗余备份系统进行建模和分析,在模型分析的基础上给出冗余备份系统的可靠性、可用性、可生存性、平均故障间隔时间等各种可信赖性重要指标。实例研究表明备份部件所处不同的状态会导致冗余备份系统具有不同的可用性。

Measurement of dependability objectively represents trustworthiness of redundant standby system. It is major criteria for evaluation of standby system service ability. Stochastic Petri Nets （SPN） has good ability for dynamic analysis of concurrency, asynchronism and uncertainty of systems. It is particularly suitable for system modeling and dependability analysis. The concepts of standby system and description of stochastic Petri Nets were discussed. Standby systems were modeled and analyzed by SPN. Based on model analysis, the reliability, availab＇ility, survivability, mean time between faults and other dependability indicators of standby system were presented. Instance study showed that different states of standby units result in different availability of standby system.