Coordinated VM Resizing and Server Tuning: Throughput, Power Efficiency and Scalability

Performance control and power management in virtualized machines (VM) are two major research issues in modern data centers. They are challenging due to complexities of hosted Internet applications, high dynamics in workloads and the shared virtualized infrastructure. Obtaining a model among VM capacity, server configuration, performance and power consumption is a very hard problem even for just one application. In this paper, we propose and develop GARL, a genetic algorithm with multi-agent reinforcement learning approach for coordinated VM resizing and server tuning. In GARL, model-independent reinforcement learning agents generate VM capacity and server configuration options and the genetic algorithm evaluates different combinations of those options for maximizing a global utilization function of system throughput and power efficiency. The multi-agent design makes GARL a scalable approach, which is important as more and more applications are hosted in data centers using cloud services. We build a testbed in a prototype data center and deploy multiple RUBiS benchmark applications. We apply a power budget in the testbed and observe superior system throughput and power efficiency of GARL. Experimental results also find that GARL significantly outperforms a representative reinforcement learning based approach in performance control. GARL shows better scalability when compared to a centralized approach.