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.