A Rejuvenation Strategy of Two-Granularity Software Based on Adaptive Control

In the process of continuous operation in a software system, a series of phenomena could lead to performance degradation of the system, namely software aging. The loss caused by software aging can be reduced through proper rejuvenation strategies, the key to which is to determine the rejuvenation thresholds. Essence of some traditional methods is to set predetermined thresholds based on empirical data. However, in some systems where the memory is shared between operating system and application software (two-granularity software system), as the memory consumption is closely related to system performance and changes constantly, using empirical thresholds may cause system outage or waste of resources. In this paper, an adaptive strategy is adopted to optimize the thresholds. Instead of fixed thresholds, the method regularly regulates the thresholds by taking feedback information in the running process into account. Especially, critical equations are constructed to calculate the thresholds by maximizing the system availability. Simulation results show that the proposed method achieves higher availability and more stable performance than that based on empirical thresholds.