Improving Energy Efficiency of Web Servers by Using a Load Distribution Algorithm and Shutting Down Idle Nodes

These years energy consumption has become the main constraint for the further improvement of computing ability of data centers. In this work, the energy efficient resource management strategies for web servers (one typical class of data centers) are discussed. We firstly introduce the daily pattern of requests sent to web servers which indicates that a simple off-line resource provisioning method would-be effective for web servers. Then, the energy efficiency of two load distribution algorithms are compared by replaying subset of a real-world Wikipedia trace in our local web service environment. The results show that, compared with the relative load distribution (RLB) algorithm, the adaptive load distribution (ALD) algorithm proposed in our previous work is more energy efficient. Finally, we demonstrate a potential that much energy can be saved by shutting down the idle nodes.