Job Completion Time on a Virtualized Server with Software Rejuvenation

This article analyzes the completion time of a job running on a virtualized server subject to software aging and rejuvenation in a virtual machine monitor (VMM). A job running on the server may be interrupted by virtual machine (VM) failure, VMM failure or VMM rejuvenation. The job interruption is categorized as either preemptive-repeat (prt), in which case the interrupted job needs to restart from the beginning, or preemptive-resume (prs), in which case the job resumes execution from the point of interruption. Using a semi-Markov process (SMP) to model the server behavior, the steady-state server availability is computed and the theory developed in Kulkarni et al. [1987] is used to obtain the Laplace-Stieltjes transform (LST) of the job completion time. In the numerical experiments, we introduce four types of aging behavior of VMM. The effectiveness of VMM rejuvenation on job completion time is discussed in association with the type of interruption it causes and the VMM aging type. With our parameter settings, VMM rejuvenation with prs job interruption improves the performance of job execution regardless of the aging type, with performance degradation is taken into account.