Reliability-aware server consolidation for balancing energy-lifetime tradeoff in virtualized cloud datacenters

Server consolidation using virtualization technologies allow large-scale datacenters to improve resource utilization and energy efficiency. However, most existing consolidation strategies solely focused on balancing the tradeoff between performance service-level-agreements (SLAs) desired by cloud applications and energy costs consumed by hosting servers. With the presence of fluctuating workloads in datacenters, the lifetime and reliability of servers under dynamic power-aware consolidation could be adversely impacted by repeated on-off thermal cycles, ware-and-tear and temperature rise. In this paper, we propose a ReliabilityAware server Consolidation stratEgy, named RACE, to address when and how to perform energy-efficient server consolidation in a reliability-friendly and profitable way. The focus is on the characterization and analysis of this problem as a multi-objective optimization, by developing an utility model that unifies multiple constraints on performance SLAs, reliability factors, and energy costs in a holistic manner. An improved grouping genetic algorithm is proposed to search the global optimal solution, which takes advantage of a collection of reliability-aware resource buffering, and virtual machines-to-servers re-mapping heuristics for generating good initial solutions and improving the convergence rate. Extensive simulations are conducted to validate the effectiveness, scalability and overhead of RACE — in improving the overall utility of datacenters while avoiding unprofitable consolidation in the long term — compared with pMapper and PADD strategies for server consolidation. Copyright c © 2013 John Wiley & Sons, Ltd.