How to cool internet-scale distributed networks on the cheap

Internet-scale Distributed Networks (IDNs) are large distributed systems that comprise hundreds of thousands of servers located in hundreds of data centers around the world. A canonical example of an IDN is a content delivery network (CDN) that delivers content to users from a large global deployment of servers around the world. IDNs consume significant amounts of energy to power their deployed server infrastructure, and nearly as much energy to cool that infrastructure. We study the potential benefits of using two new cooling technologies---open air cooling (OAC) and thermal energy storage (TES)---to reduce the energy usage as well as the operational and capital costs incurred by an IDN for cooling. We develop novel algorithms to incorporate both technologies into the IDN architecture and empirically evaluate their efficacy using extensive work load traces from Akamai's global CDN and global weather data from NOAA. Our results show that both technologies hold great promise for the future sustainability of Internet-scale distributed networks. Our algorithm for power management of TES is provably near-optimal, is the first to incorporate storage efficiency, and is broadly applicable to other storage devices such as batteries.