Availability Analysis and Improvement of Software Rejuvenation Using Virtualization

Availability of business-critical application servers is an issue of paramount importance that has received special attention from the industry and academia. To improve the availability of application servers, we have conducted a study of virtualization technology and software rejuvenation that follows a proactive fault-tolerant approach to counter act the software aging problem. We present Markov models for analyzing availability in such continuously running applications and express availability, downtime and downtime costs during rejuvenation in terms of the parameters in the models. Our results show that our approach is a practical way to ensure uninterrupted availability and optimize performance for even strongly aging applications.