Green data centers: Using hierarchies for scalable energy efficiency in large web clusters

The growth in the demand for web services requires increasing processing capacity to maintain adequate response time to customer requests and, consequently, results in an increase in the energy consumption to support this infrastructure. This work is directed to the energy saving in large scale web server clusters, towards “green” data center construction. Energy consumption reduction is fundamental due to the economic and environmental aspects involved: energy generation has high costs and produces millions of tons of carbon. However, while saving energy, the quality of service offered to the customers should be maintained above an acceptable minimum level. Our solution involves optimization techniques, the use of Dynamic Voltage and Frequency Scaling technology (DVFS), and the application of a hierarchical architecture that uses a heuristic approach to define the cluster configuration at each instant.