Power-efficient resource management for co-located virtualized web servers: A stochastic control approach

As green computing is becoming a popular computing paradigm, the issue of energy-efficient data center with performance assurance becomes increasingly important. This paper proposes a novel stochastic control approach for joint performance and power control of co-located multiple virtualized web servers. It aims at addressing the instability and inefficiency issues due to dynamic Web workloads. It features a coordinated control architecture that optimizes the resource allocation and minimizes the overall power consumption while guaranteeing the server level agreements (SLAs). Due to the interference effect among the co-located virtualized web servers and time-varying workloads, the relationship between the hardware resource assignment to different virtual servers and the web applications´ performance is considered as a coupled Multi-Input-Multi-Output (MIMO) system and formulated as an robust optimization problem. Then we propose a constrained stochastic linear-quadratic controller (cSLQC) to solve this problem by optimizing the quadratic cost function subject to linear and probabilistic constraints. Experiments on our testbed server with a variety of workload patterns demonstrate the proposed control approach´s effectiveness and power efficiency.