中文摘要：

瞄准在应用程序部件和应用程序服务器平台之间的相关性的特征，有返老还童颗粒度的二个不同层次的返老还童策略包括应用程序部件返老还童和应用程序服务器系统在这篇论文被提出返老还童。可获得性和维护费用功能借助于建立应用程序服务者老化模型和最佳的返老还童时间的边界条件被获得被分析。理论分析显示 two-levelrejuvenation 策略比传统的单个水平优异一个。最后，评估实验被执行，数字结果证明与传统的返老还童政策相比，返老还童策略在这建议纸能进一步增加应用程序服务者和还原剂维护费用的可获得性。

英文摘要：

Aiming at the characteristic of the dependency between the application components and the application server platform, a rejuvenation strategy with two different levels of rejuvenation granularities is put forward in this paper including the application component reiuvenation and the application server system rejuvenation. The availability and maintenance cost functions are obtained by means of establishing the application server aging model and the boundary condition of the optimal rejuvenation time is analyzed. Theory analysis indicates that the two-level rejuvenation strategy is superior to the traditional single level one. Finally, evaluation experiments are carried out and numerical result shows that compared with the traditional rejuvenation policy, the rejuvenation strategy proposed in this paper can further increase availability of the application server and reduce maintenance cost.