Software Rejuvenation: Analysis, Module and Applications

Software rejuvenation is the concept of gracefully terminating an application and immediately restarting it at a clean internal state In a client server type of application where the server is intended to run per petually for providing a service to its clients rejuve nating the server process periodically during the most idle time of the server increases the availability of that service In a long running computation intensive ap plication rejuvenating the application periodically and restarting it at a previous checkpoint increases the like lihood of successfully completing the application execu tion We present a model for analyzing software re juvenation in such continuously running applications and express downtime and costs due to downtime dur ing rejuvneation in terms of the parameters in that model Threshold conditions for rejuvenation to be bene cial are also derived We implemented a reusable module to perform soft ware rejuvenation That module can be embedded in any existing application on a UNIX platform with min imal e ort Experiences with software rejuvenation in a billing data collection subsystem of a telecommu nications operations system and other continuously running systems and scienti c applications in AT T