分布式系统4级嵌套的软件抗衰策略及模型分析

将软件抗衰重启合理地应用于分布式系统，实现细粒度软件抗衰，可以提高抗衰适用性，降低抗衰开销，提高软件可靠性。确定系统重启层级别，查询各层模块的直接耦合模块，进而构建出各重启层的重启链是实施细粒度软件抗衰策略的关键。针对分布式系统各级模块间控制、调用及数据访问的关系，可以制定出系统重启层标准，给出判定各级直接耦合模块和模块重启群的方法，同时定义重启优先级，进而得出各级重启链的构建规则，由此制定重启实施策略。同时综合随机Petri网及确定的有限自动机两种形式化描述方法，构建易于理解分析的4级嵌套抗衰重启模型，为实现分布式系统细粒度软件抗衰提供支持。

Model Analysis on Four-level Nested Software Anti-aging Policy of Distributed System

In order to save the cost of software rejuvenation, improve the reliability of software and ad-vance the applicability of anti-aging, the fine-grained software anti-aging was executed in distributed system. The establishment of rational rejuvenation levels, searching of direct coupling modules and e- duction of restart chains on different levels are the keys of fine-grained software rejuvenation policy. Based on coupling relation of controlling, calling and data inquiring between the modules on different levels of distributed system. The system restartable level standard was set down, a method to search the direct coupling modules and restartable set of modules was put forward, the restartable priority lev?el was defined, the constructional rule of the restartable chains on different levels was obtained, and then a policy of the retartable implement was established; and the four-level nested anti-aging retartable model was established by comprehended stochastic Petri net and determinative finite automaton. To support the anti-aging of software with fine rejuvenation granularity in distributed system.