A virtualized data center energy‐saving mechanism based on switching operating mode of physical servers and reserving virtual machines

Abstract

The energy consumption of virtualized data centers has grown very fast in last several years. Because a large number of hosts are running in an idle state, virtualized data centers waste a large amount of electric energy. To save more energy for virtualized data centers, an energy-saving mechanism is proposed based on switching operating mode of physical servers and reserving virtual machines (VMs). The main idea is that when the amount of idle VMs reaches twice of a specified threshold, half of these idle VMs are reserved to process the new task that is about to arrive, and the physical server which hosts the other half of the idle VMs is switched to the sleep mode. From the perspective of task arrival rate and sleep parameters, we use two-dimensional Markov processes to analyze the proposed energy-saving mechanisms. By using matrix geometry solutions, we theoretically estimate energy consumption and response performance. According to the numerical experiments, the proposed energy-saving mechanism obviously cut down electric energy consumption and ensures response performance. Finally, the specified threshold for the amount of VMs is optimized by building a cost function. K E Y W O R D Scost function, energy-saving mechanism, Markov chain, virtualized data center INTRODUCTIONCloud data center is a paradigm of providing network, storage, and computing functions as a service for users. 1 The cloud computing has experienced rapid growth, which results in increased size and amount of virtualized data centers. 2 The number of hosting servers in data centers is growing rapidly. Google and Microsoft have more than 1 million servers in their data centers. 3 According to estimates by International Data Corporation, the total number of virtualized data centers deployed worldwide in 2017 reached 8.6 million. 4 As a result, the global electric power consumption of these large data centers has rapidly increased. In 2010, the electric power consumption of all of data centers accounted for roughly 1.3% of that of the world.5 The total electric power consumption of all of the data centers is increasing dramatically every year. Recently, according to the 2017 report of the Forbes Technical Committee, the electric power consumption of all of data centers accounted for roughly 3% of that of the world.6 In addition to the huge cost of electricity, the energy use of virtualized data centers brings many environmental issues. As a result, energy efficiency has become a major concern for data center operators today, even more important than traditional availability and security considerations. 7 One of the main reasons for low energy efficiency is the wasted power supply when data center servers provide computing and storage functions at low utilization rates. 8 The task scheduling algorithms have a significant impact on the energy consumption of these large data centers. 3 Green cloud computing has become a trend in the development of current data centers. It is very important to solve the energy efficient resource scheduling problems...