Optimizing Software Rejuvenation Policies under Interval Reliability Criteria

Software aging often affects the performance of software systems and eventually causes them to fail. A complementary approach to handle transient software failures due to the software aging is called software rejuvenation, and can be regarded as a preventive and proactive solution that is particularly useful for counteracting the phenomenon of software aging. In this paper, we consider the optimal software rejuvenation policies maximizing the interval reliability by using the Markov regenerative processes. We derive analytically the optimal software rejuvenation timing which maximizes the limitting interval reliability or the interval reliability with exponentially distributed operation time. Further, we examine numerically the transient behavior of the interval reliability at an arbitrary operation time. Our results under the interval reliability criteria are extentions of some earlier works, since the interval reliability involves the point wise system availability and the common reliability function as special cases.