Minimizing Energy Dissipation in Content Distribution Networks Using Dynamic Power Management

The growing end-user demand for video services with superior quality on laptops, tablets, and smartphones spurs the deployment of telco content distribution networks (CDNs). Such CDNs provide scalable and bandwidth-efficient video delivery thanks to disk-packed cache servers deployed in the telco's data centers near the clients. However, a sustainable growth of these CDNs may be hindered by their lack of energy proportionality. In this paper we propose to apply dynamic power management (DPM) to the CDN's cache servers and their disks to increase the CDN's energy efficiency. We evaluate DPM using a CDN energy simulator driven by HTTP adaptive-streaming workload traces recorded by an operational CDN delivering IPTV to mobile devices. Even for a minimally-provisioned CDN, we observe a reduction of the energy dissipation by approximately 30% thanks to large cyclic load fluctuations characteristic of IPTV delivery.