Towards Energy Efficient Data Intensive Computing Using IEEE 802.3az

Energy efficiency is an increasingly important requirement for computing and communication systems, especially with their increasing pervasiveness. The IEEE 802.3az protocol reduces the network energy consumption by turning active copper Ethernet links to a low power model when no traffic exists. However, the effect of 802.3az heavily depends on the network traffic patterns which makes system level energy optimization challenging. In clusters, distributed data intensive applications that generate heavy network traffic are common, and in turn the required network devices can consume large amounts of energy. In this research, we examined the 802.3az technology with the goal of applying it in clusters. We defined an energy budget calculator that takes energy-efficient Ethernet into account by including the energy models derived from tests of 802.3az enabled devices. The calculator is an integral tool in a global strategy to optimize the energy usage of applications in a high performance computing environment. We show a few practical examples of how real applications can better plan their execution by integrating this knowledge in their decision strategies.