Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 2007 Interactive and verifiable web services composition, specification reformulation and substitution Jyotishman Pathak Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Artificial Intelligence and Robotics Commons Recommended Citation Pathak, Jyotishman, "Interactive and verifiable web services composition, specification reformulation and substitution" (2007). Retrospective Theses and Dissertations. 15586. https://lib.dr.iastate.edu/rtd/15586 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Interactive and verifiable web services composition, specification reformulation and substitution by Jyotishman Pathak A dissertation submitted to the graduate faculty in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Major: Computer Science Program of Study Committee: Vasant Honavar, Major Professor Samik Basu Drena Dobbs Shashi Gadia Robyn Lutz James McCalley Iowa State University Ames, Iowa 2007 Copyright c Jyotishman Pathak, 2007. All rights reserved. UMI Number: 3289388 UMI Microform 3289388 Copyright 2008 by ProQuest Information and Learning Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest Information and Learning Company 300 North Zeeb Road P.O. Box 1346 Ann Arbor, MI 48106-1346 ii DEDICATION To my family iii TABLE OF CONTENTS LIST OF FIGURES .................................. vii LIST OF TABLES ................................... ix ACKNOWLEDGMENTS ............................... x ABSTRACT ....................................... xii CHAPTER 1. INTRODUCTION ......................... 1 1.1 Service-Oriented Computing ............................. 1 1.2 Motivation: Web Service Composition ....................... 3 1.2.1 What are Web Services? ........................... 4 1.2.2 What is Web Service Composition? ..................... 7 1.2.3 Research Questions and Challenges ..................... 9 1.3 Goals and Main Results ............................... 11 1.4 Thesis Outline .................................... 14 CHAPTER 2. RELATED WORK ......................... 16 2.1 Web Services: Standards and Related Technologies ................ 16 2.2 Web Service Composition .............................. 19 2.2.1 Techniques based on Formal Methods ................... 19 2.2.2 Techniques based on AI Planning ...................... 22 2.2.3 Techniques based on Model-Driven Architectures ............. 25 2.2.4 Techniques based on Graph Theory .................... 26 2.3 Additional Research Areas Related to Web Service Composition ........ 28 2.3.1 Web Service Substitution .......................... 28 iv 2.3.2 Web Service Adaptation ........................... 30 2.4 Discussion ....................................... 32 CHAPTER 3. WEB SERVICES AND LABELED TRANSITION SYSTEMS 34 3.1 Representing Web Services as Labeled Transition Systems ............ 34 3.1.1 Labeled Transition Systems ......................... 35 3.1.2 Equivalence of Labeled Transition Systems ................ 39 3.1.3 Composition of Labeled Transition Systems ................ 41 3.2 Transforming Web Service Descriptions to Labeled Transition Systems ..... 42 3.2.1 Mapping State Machines to Labeled Transition Systems ......... 43 3.2.2 Mapping BPEL to Labeled Transition Systems .............. 44 3.3 Discussion ....................................... 47 CHAPTER 4. WEB SERVICE COMPOSITION ................ 49 4.1 Introduction and Problem Description ....................... 49 4.2 Illustrative Example ................................. 52 4.3 Our Approach ..................................... 55 4.3.1 Service Composition in MoSCoE: An Overview .............. 55 4.3.2 Algorithm for Mediator Synthesis ...................... 55 4.3.3 Analysis of Failure of Composition ..................... 62 4.3.4 Theoretical Analysis ............................. 64 4.3.5 Composition using Non-Functional Requirements ............. 66 4.4 Discussion ....................................... 69 CHAPTER 5. WEB SERVICE SPECIFICATION REFORMULATION . 72 5.1 Introduction and Problem Description ....................... 72 5.2 Illustrative Example ................................. 74 5.3 Our Approach ..................................... 78 5.3.1 Functionally Equivalent Web Services ................... 78 5.3.2 Web Service Dependency Matrix ...................... 80 5.3.3 Generation of the Dependency Matrix ................... 82 v 5.3.4 Algorithm for Reformulation-based Web Service Composition ...... 85 5.4 Discussion ....................................... 91 CHAPTER 6. WEB SERVICE SUBSTITUTION ................ 94 6.1 Introduction and Problem Description ....................... 94 6.2 Illustrative Example ................................. 96 6.3 Our Approach ..................................... 98 6.3.1 Overview ................................... 98 6.3.2 Representing Web Service Properties in Mu-Calculus ........... 100 6.3.3 Quotienting Mu-Calculus Properties .................... 102 6.3.4 Substitutability of Web services ....................... 106 6.3.5 Theoretical Analysis ............................. 108 6.4 Discussion ....................................... 109 CHAPTER 7. SEMANTIC INTEROPERABILITY .............. 111 7.1 Introduction and Problem Description ....................... 111 7.2 Ontologies and Mappings .............................. 113 7.3 Our Approach ..................................... 116 7.3.1 Ontology-based Service Discovery ...................... 117 7.3.2 Ontology-based Service Composition .................... 122 7.4 Discussion ....................................... 129 CHAPTER 8. SYSTEM ARCHITECTURE AND EVALUATION ..... 131 8.1 MoSCoE Architecture ................................ 131 8.2 Implementation .................................... 134 8.2.1 Back-End Implementation .......................... 135 8.2.2 Front-End Implementation ......................... 137 8.3 Empirical Evaluation ................................. 141 8.3.1 Health4U Case Study ............................ 141 8.3.2 e-Warehouse Case Study .......................... 146 vi CHAPTER 9. CONCLUSIONS .......................... 148 9.1 Summary ....................................... 148 9.2 Contributions ..................................... 150 9.3 Further Work ..................................... 151 APPENDIX A. BPEL process description of e-Auction service ........ 155 APPENDIX B. WSDL description of e-Auction service ............ 157 BIBLIOGRAPHY ................................... 159 vii LIST OF FIGURES Figure 1.1 Diagram of a Service-Oriented Architecture ............... 4 Figure 1.2 Relationship Between Standard Web Service Specifications ....... 5 Figure 1.3 Service Input/Output & Behavioral Descriptions ............ 6 Figure 1.4 Two Different Types of Composition Models ............... 7 Figure 2.1 Web Services Protocol Stack ........................ 17 Figure 3.1 Labeled Transition System representation of e-Buy service ....... 36 Figure 3.2 Example Labeled Transition Systems ................... 40 Figure 3.3 Composition of Labeled Transition Systems ............... 42 Figure 3.4 State Machine representation of the e-Buy service ............ 43 Figure 3.5 Labeled Transition System representation of e-Auction service . 46 Figure 4.1 LTS representation of (a) Health4U (b) The Mediator ......... 53 Figure 4.2 LTS representation of component services ................ 54 Figure 4.3 LTS representation of component services ................ 63 Figure 5.1 Reformulation-based Service Composition ................ 74 Figure 5.2 LTS representation & mapping of e-Buyer service ........... 75 Figure 5.3 LTS representation of component services ................ 76 Figure 5.4 Dependency Matrices ............................ 84 Figure 6.1 LTS representation of sample services ................... 97 Figure 6.2 Quotienting Rules .............................. 104 Figure 6.3 Results of Quotienting ........................... 106 viii Figure 7.1 Weather Description with F-Sensor .................... 112 Figure 7.2 Weather Ontology of Company K1 .................... 114 Figure 7.3 Weather Ontology of Company K2 .................... 115 Figure 7.4 Sample QoS Taxonomy ........................... 119 Figure 7.5 Workflow Schema Graph .......................... 123 Figure 7.6 Ontology-Extended Workflow Component ................ 125 Figure 7.7 Ontology-Extended Component Instance ................. 127 Figure 8.1 MoSCoE Architectural Diagram ...................... 132 Figure 8.2 UML Representation of a Labeled Transition System .......... 135 Figure 8.3 Labeled Transition System Editor-1 .................... 137 Figure 8.4 Labeled Transition System Editor-2 .................... 138 Figure 8.5 Importing Labeled Transition Systems .................. 139 Figure 8.6 Service Composition and Repository ................... 140 Figure 8.7 Service Composition Error ......................... 141 Figure 8.8 LTS representation of (a) Health4U’ (b) Health4U” ........... 142 Figure 8.9 LTS representation of Health4U’ component services .........