Dominic Duggan, PhD, is a faculty member in the Department of Computer Science at Stevens Institute of Technology. His research interests are in the design and development of secure and reliable software systems. His publications have appeared in leading journals and conferences.

• List of Figures xv Acknowledgements xxiii1. Introduction 1References / 62. Middleware 72.1 Enterprise Information Systems / 72.2 Communication / 122.3 System and Failure Models / 212.4 Remote Procedure Call / 342.5 Message-Oriented Middleware / 422.6 Web Services and Service-Oriented Architecture (SOA) / 462.7 Cloud Computing / 522.8 Naming and Discovery / 552.9 Further Reading / 56References / 573. Data Modeling 593.1 Entities and Relationships / 603.1.1 Concepts and Entities / 603.1.2 Attributes and Relationships / 613.1.3 Properties of Relationship Types / 653.1.4 Special Relationship Types / 693.2 XML Schemas / 743.3 Defining New Types / 793.3.1 Defining Simple Types / 793.3.2 Defining Complex Types / 823.4 Derived Types / 853.4.1 Derived Simple Types / 863.4.2 Derived Complex Types / 873.5 Document Hierarchies / 943.6 Relationship Types in XML Schemas / 983.7 Metaschemas and Metamodels / 1003.8 Further Reading / 102References / 1024. Data Processing 1044.1 Processing XML Data / 1044.1.1 Tree Processing / 1054.1.2 Schema Binding / 1094.1.3 Stream Processing / 1144.1.4 External Processing / 1194.2 Query Languages and XQuery / 1224.3 XML Databases / 1344.3.1 Storage as Relational Tables / 1354.3.2 Storage as Large Strings / 1374.3.3 Native XML Storage / 1374.4 Web Services / 1384.4.1 SOAP: (not so) Simple Object Access Protocol / 1394.4.2 WSDL: Web Services Description Language / 1454.4.3 Web Service Policy / 1554.5 Presentation Layer: JSON and JQUERY / 159References / 1665. Domain-Driven Architecture 1675.1 Software Architecture / 1675.2 Domain-Driven Design / 1685.3 Application Frameworks / 1755.4 Domain-Specific Languages (DSLs) / 1805.5 An Example API for Persistent Domain Objects / 1885.6 Domain-Driven Architecture / 1975.7 Further Reading / 205References / 2056. Service-Oriented Architecture 2076.1 Services and Procedures / 2076.2 Service-Oriented Architecture (SOA) / 2116.3 Service Design Principles / 2166.4 Service-Oriented Architecture (SOA) Governance / 2186.5 Standardized Service Contract / 2216.5.1 Operations Contract / 2226.5.2 Data Contract / 2236.5.3 Policy Contract / 2246.5.4 Binding Contract / 2266.5.5 Contract Versioning / 2316.6 Service Loose Coupling / 2376.6.1 Motivation for Loose Coupling / 2376.6.2 Contract Development / 2396.6.3 Loose Coupling Patterns / 2426.6.4 Cost of Loose Coupling / 2466.7 Service Abstraction / 2486.7.1 Platform Abstraction / 2486.7.2 Protocol Abstraction / 2496.7.3 Procedural Abstraction / 2616.7.4 State Abstraction / 2646.7.5 Data Abstraction / 2696.7.6 Endpoint Abstraction / 2786.8 Service Reusability / 2786.8.1 Parameterization and Bounded Polymorphism / 2796.8.2 Subtyping, Inheritance, and Contracts / 2846.8.3 Does Service-Oriented Architecture Require Subtyping? / 2896.8.4 Patterns for Service Reusability / 2926.9 Service Autonomy / 2996.9.1 Replicating Computation / 3006.9.2 Replicating State / 3036.9.3 Sources of Errors and Rejuvenation / 3086.9.4 Caching / 3136.10 Service Statelessness / 3236.10.1 Contexts and Dependency Injection / 3316.11 Service Discoverability / 3366.11.1 Global Discovery / 3366.11.2 Local Discovery / 3376.11.3 Layered Naming / 3476.12 Further Patterns / 3516.13 Further Reading / 352References / 3527. Resource-Oriented Architecture 3597.1 Representational State Transfer / 3597.2 RESTful Web Services / 3697.3 Resource-Oriented Architecture (ROA) / 3797.4 Interface Description Languages / 3877.4.1 Web Services Description Language (WSDL) / 3877.4.2 Web Application Description Language (WADL) / 3907.5 An Example Application Program Interface (API) for Resource-Oriented Web Services / 3967.6 Hypermedia Control and Contract Conformance / 4067.7 Concluding Remarks / 4127.8 Further Reading / 414References / 414Appendix A: Introduction to Haskell 416A.1 Types and Functions / 416A.2 Type Classes and Functors / 425A.3 Monads / 431A.4 Further Reading / 436References / 436Appendix B: Time in Distributed Systems 437B.1 What Time Is It? / 437B.2 Time and Causality / 443B.3 Applications of Logical and Vector Time / 450B.3.1 Mutual Exclusion / 450B.3.2 Quorum Consensus / 451B.3.3 Distributed Logging / 456B.3.4 Causal Message Delivery / 458B.3.5 Distributed Snapshots / 463B.4 Virtual Time / 468B.5 Further Reading / 470References / 470Index 473