Comparative Analysis of Migration-Based Rejuvenation Schedules on Cloud Availability

Software aging refers to performance degradation faced on long-running execution software. The software infrastructure supporting Cloud Computing systems may suffer from aging effects. Such a phenomenon was already reported for virtual infrastructure managers and virtual machine monitors. In this sense, software rejuvenation is a technique of proactive fault tolerance to deal with effects of software aging. This paper proposes a comprehensive availability model for two different types of rejuvenation scheduling based on live migration mechanism, one with a test before migration, and other without. We evaluate five different scenarios, with distinct time intervals for triggering the rejuvenation. The main goal is to explain the benefits gained from the use of this type of rejuvenation technique, as well as understand the differences between the two approaches analyzed. The results show that the utilization of a schedule with a checking mechanism before rejuvenation can bring a significant improvement on system availability.