Energy- and Quality of Experience-Aware Dynamic Resource Allocation for Massively Multiplayer Online Games in Heterogeneous Cloud Computing Systems

Massively multiplayer online games (MMOGs) are a new type of large-scale interactive applications providing a seamless virtual world for millions of gamers from all over the world. Traditionally, MMOGs are implemented using a client-server architecture. With the maturity of cloud computing, many MMOG providers such as Blizzard Entertainment and Jagex Limited have begun to utilize virtualized machines to serve their consumers due to the elasticity, adaptability, and cost advantages of clouds. It is a major challenge for MMOG providers how to dynamically allocate resources in an on-demand pattern in order to reduce the energy cost associated with operating a MMOG cloud while providing good-enough quality of experience (QoE) for MMOG gamers. In this article, we propose a dynamic resource allocation scheme for MMOGs in heterogeneous cloud computing systems, which makes use of both dynamic virtual machine (VM) consolidation among physical machines (PMs) and long short-term memory based VM resizing at physical machine level to achieve the energy efficiency and desired QoE requirements. Our scheme considers multiple types of resources, characteristic of AFK (away from keyboard) gamers, heterogeneous PMs and VMs, strict QoE requirements and overheads incurred due to migrating VMs. Furthermore, a novel hybrid algorithm based on differential evolution and modified first-fit heuristic is presented for dynamic consolidation of VMs in heterogeneous cloud data centers. The experiment results show that, compared to the traditional over-provisioning policy, our resource allocation scheme can achieve up to 44.8% energy savings while ensuring the QoE requirements of MMOG gamers under rapidly changing workloads.