Software Life-Extension: A New Countermeasure to Software Aging

This paper presents software life-extension, a new technique for counteracting software aging by preventive operation to extend the lifetime of software execution. Software aging is a phenomenon of progressive degradation of execution environment due to aging-related software faults and it might cause resource depletion resulting in system failures. To extend the lifetime of the software affected by aging, we use a virtual machine to execute the software and allocate additional memory to the virtual machine upon software aging detection. Although software life-extension is a temporal solution as it only postpones the occurrence of a failure, it provides a simple, cost-effective, and non-intrusive countermeasure to software aging. The feasibility and effectiveness of software life-extension are studied by the experiments on memcached, a widely adopted general-purpose in-memory cache server. From the experimental results, we present a Semi-Markov process (SMP) describing the general behavior of software life-extension and analyze the model which gives the prediction of the system availability as well as the user-perceived availability.