Study on Four-Level Emergency Rejuvenation for Survivable System

A method of four-level emergency rejuvenation for survivable system was proposed. Firstly, failure models of survivable system were formally described based on stochastic Petri nets, in which a number of measurable index parameters for rejuvenation were also given out. And then a four-level recursive emergency rejuvenation strategy was presented based on system-level, service-level, process-level and thread-level, the computing process of rejuvenation priority is also defined and the chain of rejuvenation is obtained. Eventually, the implementation process of four-level autonomous emergency rejuvenation strategy was described using stochastic Petri nets. Compared with the traditional cyclical recovery strategy, the proposed method reduced the time and costs of emergency recovery, and enhanced the recoverable elasticity of survivable system.