Dynamic Resource Management

Abstract

First of all I would like to thank my supervisor Prof. Dr. Wolfgang Nebel for his support and helpful advices concerning the principals of academic work. His contacts to industrial companies further helped me to gather some practical insights into the topic of this thesis. The theoretical concepts developed in this thesis could very closely address real practical issues due to this background. In addition, I would like to thank Prof. Dr. Michael Sonnenschein for taking the time to review this document. Much of the work presented in this thesis was supported by two of my students: Pierre Petliczew and Daniel Schlitt. Thank you both for your good work. I would also like to thank my colleagues for many constructive discussions; especially Henrik Lipskoch for helping me with mathematical background, Kiril Schröder and Daniel Schlitt for discussions about the concepts, and Domenik Helms and Gunnar Schomaker for some tips concerning the formal representation of some optimization problems. Additionally, special thanks to the NOWIS company for providing me very good evaluation data to assess my concepts. A large portion of my work was further supported by the OFFIS Institute for Information Technology. I did most of the research within the research project "Energy Efficiency in Data Centers". Finally, an internal scholarship helped me to finish my work and to write down this thesis. And last but not least I want to thank my family for their support. Especially the last two month of my work were hard for me for several reasons. Thank you for your help. *** Ein spezieller Dank soll an dieser Stelle an meine Familie für ihre mentale Unterstützung gehen. Die letzten zwei Monate dieser Arbeit waren aus verschiedenen Gründen nicht einfach für mich. Vielen Dank für Eure Hilfe. ix Performanzziele grundsätzlich nicht ausgeschlossen werden. Diese traten aber nur in weniger als 0.2% der Simulationszeit tatsächlich auf. xiii 2007 2010 2015 2020 network and telecom servers and data centers devices in business companies devices in households 55,4 58,4 63,0 year 66,7 Figure 1.1: Estimated energy consumption caused by ICT consumers in Germany[112] Consumer electronics-first and foremost the entertainment electronics-will take the biggest portion of the ICT's energy consumption in the next few years, as illustrated in Figure 1.1. But one can also note that especially data centers and the Internet will take an ever growing share due to an exponentially increasing demand. Different reasons motivate to address the high power consumption in data centers already today. Carbon dioxide emitted while electric power is generated is thought to cause ecological problems. Reducing the energy consumption may help to solve this issue. Additionally, data center operators are motivated by economical aspects. Energy cost form a significant part of the overall costs in data centers[115]. In addition, simple technical reasons need to be addressed. Some modern data centers would have the capacity to host additional servers but they do not get the power from...