title: A comprehensive availability modeling and analysis of a virtualized servers system using stochastic reward nets.
abstract: It is important to assess availability of virtualized systems in IT business infrastructures. Previous work on availability modeling and analysis of the virtualized systems used a simplified configuration and assumption in which only one virtual machine (VM) runs on a virtual machine monitor (VMM) hosted on a physical server. In this paper, we show a comprehensive availability model using stochastic reward nets (SRN). The model takes into account (i) the detailed failures and recovery behaviors of multiple VMs, (ii) various other failure modes and corresponding recovery behaviors (e.g., hardware faults, failure and recovery due to Mandelbugs and aging-related bugs), and (iii) dependency between different subcomponents (e.g., between physical host failure and VMM, etc.) in a virtualized servers system. We also show numerical analysis on steady state availability, downtime in hours per year, transaction loss, and sensitivity analysis. This model provides a new finding on how to increase system availability by combining both software rejuvenations at VM and VMM in a wise manner.
authors.affiliation: Department of Computer Engineering, Korea Aerospace University, 76 Hanggongdaehang-ro, Deogyang-gu, Goyang-si, Gyeonggi-do 412-791, Republic of Korea.
authors.forename: Tuan Anh
authors.identifier: 0000-0002-9123-3584
authors.initials: TA
authors.lastname: Nguyen
authors.affiliation: Department of Computer Science and Software Engineering, College of Engineering, University of Canterbury, Private 4800, Christchurch 8140, New Zealand.
authors.forename: Dong Seong
authors.initials: DS
authors.lastname: Kim
authors.affiliation: Department of Computer Engineering, Korea Aerospace University, 76 Hanggongdaehang-ro, Deogyang-gu, Goyang-si, Gyeonggi-do 412-791, Republic of Korea.
authors.forename: Jong Sou
authors.initials: JS
authors.lastname: Park
mesh_terms: D003199:Computer Systems; D007256:Information Systems; D008962:Models, Theoretical; D012201:Reward; D013269:Stochastic Processes; D013997:Time Factors