Versioning of Web service interfaces

Abstract

This thesis investigates the problem of "design for change" in the context of Web Service based information systems. It describes the current status of architecting Web Services, an implementation of the Service Oriented Architecture. It also discusses the availability and support for higher level specifications, such as security, that leverage the baseline standards like SOAP (Simple Object Access Protocol), WSDL (Web Service Description Language), and UDDI (Universal Discovery, Description and Integration). This thesis examines versioning as an additional specification. It discusses the Web Service enabled programming environment by addressing the various causes of change. Two levels of versioning are identified to deal with this problem--Schema level and Interface level versioning. For Schema level versioning, the extensibility models and their versioning support are discussed. Other techniques of using distinct namespaces and custom versioning tags are presented by means of samples. The second level of versioning, the Interface Level Versioning, discusses implementation of versioning logic using the current standards of WSDL 1.1. In addition, the ongoing recommendations and efforts in this field are stated.