Keynote: Energy-Efficient Distributed Systems

It is now critical to reduce the consumption of natural resources, especially petroleum to resolve air pollutions. Even in information systems, we have to reduce the total electrical power consumption. A cloud computing system is composed of a huge number of server computers like Google file systems. There are many discussions on how to reduce the total power consumption of servers, e.g. by turning off servers which are not required to execute requests from clients. A Peer-to-Peer (P2P) system is another type of information system which is composed of a huge number of peer computers where various types of applications are autonomously performed. In this talk, I would like to discuss how to reduce the total electric energy consumption of types of distributed systems, i.e. computers interconnected in networks. We consider two types of distributed applications, transaction-based and communication-based applications. In the transaction-based applications, CPU resources are mainly consumed like Web applications. On the other hand, in the communication-based applications, a large volume of data is transmitted in the network like file transfer applications. Based on the experimental studies of computers and networks, we would like to discuss models which show how much electric power is consumed in distributed systems for types of applications. Finally, we would like to discuss how to allocate processes/requests to computers so that not only some requirements (like time constraint) are satisfied but also the total electric power consumption is minimized.