MEE10:13 Performance Evaluation of DHTs for Mobile Environment Monirul Islam Bhuiya Rakib Mohammad Ahsan This thesis is presented as part of Degree of Master of Science in Electrical Engineering Blekinge Institute of Technology December 2009 Blekinge Institute of Technology School of Engineering Department of Telecommunication Supervisor: Alexandru popescu & Karel De Vogeleer Examiner: Professor Adrian Popescu -1- -2- ABSTRACT istributed Hash Table (DHT) systems are an important part of peer-to-peer routing D infrastructures. They enable scalable wide-area storage and retrieval of information, and will support the rapid development of a wide variety of Internet-scale applications ranging from naming systems and file systems to application-layer multicast. A lot of research about peer-to-peer systems, today, has been focusing on designing better structured peer-to-peer overlay networks or Distributed Hash Tables (DHTs). As far as we concern, not so many papers, however, have been published in an organized way to check the adaptability of the existing four DHTs namely Content Addressable Network (CAN), Chord, Pastry and Tapestry for mobile environments. This thesis presents an attempt to evaluate the performances of these DHTs including adaptability with mobile environments. For this we survey these DHTs including existing solutions and based on that we decide our own conclusion. -3- -4- ACKNOWLEDGEMENT Fast of all we are grateful to our God, the most gracious and merciful, who give us energy and such kind of knowledge which is really helped us to perform well in difficult situation within thesis work. Also we would like to express our gratitude from heart for our parents, who supported us during this total time period. We really like to appreciate our thesis supervisors Alexandru popescu and Karel De Vogeleer, of the School of Engineering, Blekinge Institute of Technology (BTH), Sweden, for their helping, guiding with many inspiring ideas, steady encouragement and collaboration for doing well in our thesis work. We also like to give thanks to BTH and all other employees of BTH, who really helped us and suggest the right way to reach our goal in many awful situations. Finally, we are obliged to many of our friends for their unbelievable help, continuous encouragement and trust on us. We would like to dedicate our thesis work to all of our friends and to our grate parents. -5- -6- TABLE OF CONTENT ABSTRACT .............................................................................................................................................................. 3 ACKNOWLEDGEMENT ............................................................................................................................................ 5 TABLE OF CONTENT ............................................................................................................................................... 7 LIST OF FIGURE .................................................................................................................................................... 11 LIST OF TABLE ...................................................................................................................................................... 13 CHAPTER ONE ...................................................................................................................................................... 15 INTRODUCTION ................................................................................................................................................... 15 1.1. INTRODUCTION ..................................................................................................................................................... 15 1.2. OBJECTIVE ............................................................................................................................................................ 15 1.3. MOTIVATION ........................................................................................................................................................ 16 1.4. CONTRIBUTION ..................................................................................................................................................... 16 1.5. OUTLINE OF THE THESIS .......................................................................................................................................... 17 CHAPTER TWO ..................................................................................................................................................... 19 BACKGROUND ..................................................................................................................................................... 19 2.1. PEER TO PEER NETWORK .................................................................................................................................. 19 2.1.1 INTRODUCTION: ......................................................................................................................................... 19 2.1.2 P2P ARCHITECTURE: ................................................................................................................................... 19 2.2. OVERLAY NETWORK ......................................................................................................................................... 23 2.2.1 INTRODUCTION: ......................................................................................................................................... 23 2.2.2 WORKING MODEL OF OVERLAY NETWORKS [3]: ....................................................................................... 24 2.2.3 COSTS: ........................................................................................................................................................ 25 2.2.4 SOME BENEFITS: ........................................................................................................................................ 25 2.2.5 SOME PROBLEMS: ...................................................................................................................................... 26 2.3. DISTRIBUTED HASH TABLE ................................................................................................................................ 27 2.3.1 INTRODUCTION: ......................................................................................................................................... 27 2.3.2 ARCHITECTURE OF DHT: ............................................................................................................................. 28 A. Client: .......................................................................................................................................................................... 28 B. Service: ........................................................................................................................................................................ 29 C. API: ............................................................................................................................................................................. 29 D. DDS Library: ............................................................................................................................................................... 29 E. Brick: ........................................................................................................................................................................... 29 2.3.3 STRUCTURE OF DHT: ............................................................................................................................. 30 CHAPTER THREE ................................................................................................................................................... 31 OVERVIEW OF EXISTING DHT’S ............................................................................................................................ 31 3.1 CONTENT ADDRESSABLE NETWORK (CAN) ........................................................................................................ 31 3.1.1 INTRODUCTION: ......................................................................................................................................... 31 3.1.2 WORKING MODEL: ..................................................................................................................................... 32 A. Node Joining: .......................................................................................................................................................... 32 B. Bootstrapping Nodes: ............................................................................................................................................. 33 -7- C. Finding own zone: ................................................................................................................................................... 33 D. Neighbors’ Node: .................................................................................................................................................... 34 E. Node Leaving: ......................................................................................................................................................... 34 F. Node Failure: .......................................................................................................................................................... 35 G. Routing: .................................................................................................................................................................