Audition of Web Services for Testing Conformance to Open Specified Protocols

Abstract

Abstract.A Web Service (WS) is a type of component specifically conceived for distributed machine-to-machine interaction. Interoperability between WSs involves both data and messages exchanged and protocols of usage, and is pursued via the establishment of standard specifications to which service providers must conform. In previous work we have envisaged a framework for WS testing. Within this framework, this paper focuses on how the intended protocol of access for a standard service could be specified, and especially on how the conformance of a service instance to this specified protocol can then be tested. We propose to augment the WSDL description with a UML2.0 Protocol State Machine (PSM) diagram. The PSM is intended to express how, and under which conditions, the service provided by a component through its ports and interfaces can be accessed by a client. We then propose to translate the PSM to a Symbolic Transition System, to which existing formal testing theory and tools can be readily applied for conformance evaluation. A simple example illustrates the approach and highlights the peculiar challenges raised by WS conformance testing.

Model-Based Testing of Environmental Conformance of Components

“…This is very useful when implementations of such components are not yet available, or if for reasons like security or safety, a simulated replacement is preferred. The audition framework for testing Web Services [2] is currently instantiated with a test engine which combines symbolic versions of the ioco [5] and eco techniques to allow for sophisticated testing of Service Oriented Architectures.…”

“…This is also the approach of recent, service-oriented testing frameworks like audition [2]. This framework assumes behavioral specifications of the provided service interfaces.…”

Model-Based Testing in Cloud Brokerage Scenarios

“…Previous research on service testing has come out of strategies for testing ServiceOriented Architectures (SOA) [5,6,7,8]. The emphasis is on provider-based testing of services, using translations into agreed web standards [5].…”

“…The emphasis is on provider-based testing of services, using translations into agreed web standards [5]. For example, Bertolino et al [6] translate category-partition testing to XML [6], Heckel et al devise a graphbased approach [7] and a contract-based approach [8] to exercise service functional protocols in a black-box way. A few approaches [9,10,11] have developed finite state-based testing methods, recognizing the state-based nature of services, but find it necessary to augment web standards, which only describe service interfaces (WSDL 1 ) and message formats (SOAP 2 ), with additional semantic information, in order to capture how the services should behave.…”

“…Furthermore, there is no unified testing approach adopted by providers and brokers, since there is no shared formal specification of the service, so it is unclear whether the same QA has been applied across different service implementations, or across different host platforms. The need for commonality in service description and repeatable quality assurance after testing on multiple platforms is what distinguishes the current research from other work on service testing [5][6][7][8][9][10][11].…”