Formalizing of web-services specifications using temporal logics

2011

Abstract This paper presents a methodology for generating a web service" stub" that simulates the behaviour of a real-world SOAP web service. The simulation is driven by a formal description of the original service's input and output parameters, messages, and ordering constraints between messages, using an extension of Linear Temporal Logic called LTL-FO+.

2005

Abstract. In this paper we present an approach for modelling and analyzing time-related properties of Web service compositions defined as a set of BPEL4WS processes. We introduce a formalism, called Web Service Timed State Transition Systems (WSTTS), to capture the timed behavior of the composite web services. We also exploit an interval temporal logic to express complex timed assumptions and requirements on the system's behavior.

2006

Abstract In this paper we present an approach for modelling and analyzing time-related properties of Web service compositions defined as a set of BPEL4WS processes. We introduce a formalism, called Web service timed state transition systems (WSTTS), to capture the timed behavior of the composite Web services. We also exploit an interval temporal logic to express complex timed assumptions and requirements on the system's behavior.

Proceedings of the 17th International Conference on Enterprise Information Systems, 2015

Web service composition is studied by many works, and constitutes the heart of a great research activity. However, the majority of this work does not take into account all temporal constraints imposed by the service provider and the users in the composition process. Incorporating temporal constraints in Web service composition result in more complex model and make crucial the verification of temporal consistence during the modeling (at design time) and then during the execution (at run time). In this paper, we presented H-Service-Net model for Web service composition with time constraints, and propose a modular approach for modeling composition with time constraint using Extend time unit system (XTUS), Allen's interval algebra and comparison operators in a time Petri net model.

International Journal on Semantic Web and Information Systems

This article describes how incorporating temporal constraints in web service composition results in more complex models and makes the verification of temporal consistency during the modeling and execution crucial. This article proposes a model named H-Service-Net based on the time petri net model to control and manage temporal consistency; the model also supports time constraints and exception handling. First, this approach proposes a modular approach for modeling composition using Extend Time Unit System, Allen's interval algebra, and comparison operators in a time petri net model to consider all types of temporal constraints. Subsequently, this article presents algorithms on checking temporal consistency and mechanism for exception handling and validating the system in an implementation tool (H-Service-Editor) based on the proposed approach that uses BizTalk Server 2013 to evaluate the implementation of temporal constraints and timeout exception handling. Finally, an exhaustiv...

2006

In this paper we address the problem of qualitative and quantitative analysis of timing aspects of Web service compositions defined as a set of BPEL4WS processes. We introduce a formalism, called Web Service Timed State Transition Systems (WSTTS), to capture the timed behavior of the composite web services. We also exploit an interval temporal logic to express complex timed assumptions and requirements on the system's behavior. Building on top of this formalization, we provide techniques and tools for modelchecking BPEL4WS compositions against time-related requirements. We also present a symbolic algorithm that can be used to compute duration bounds of behavioral intervals that satisfy such requirements. We perform a preliminary experimental evaluation of our approach and tools with the help of an e-Government case study.

Lecture Notes in Computer Science, 2008

As the range of services available on the Web increase, new value added services can be created by composing existing ones. It is then vital to ensure that compositions of web services are free from errors such as deadlocks and synchronisation conflicts. Current techniques are lacking in this regard because they either (i) do not consider all the different types of temporal relationships that exist between interactions, or (ii) do not support all types of interactions (i.e. only send and receive, not service and invoke). In this paper we introduce an approach that overcomes these problems. First, a communication model is generated by composing interactions of constituent services. Then, the temporal relationships between all the interactions of the communication model are found using a reasoning mechanism. While doing so, these relationships are compared against those specified in descriptions of interaction protocols, to detect any deadlocks or synchronisation conflicts.

In this paper we address the problem of qualitative and quantitative analysis of timing aspects of Web service compositions defined as a set of BPEL4WS processes. We introduce a formalism, called Web Service Timed State Transition Systems (WSTTS), to capture the timed behavior of the composite web services. We also exploit an interval temporal logic to express complex timed assumptions and requirements on the system's behavior. Building on top of this formalization, we provide techniques and tools for modelchecking BPEL4WS compositions against time-related requirements. We also present a symbolic algorithm that can be used to compute duration bounds of behavioral intervals that satisfy such requirements. We perform a preliminary experimental evaluation of our approach and tools with the help of an e-Government case study.

Timed Automata is a well known formalism for the description of Real-Time System. In this paper we show that it is useful for modelling and analyzing Web Services with time constraints. For our purposes it is enough with the choreography level of the Web Services Architecture, so Web Services descriptions written in WSCDL (a XML-based description languages) are translated to timed automata models. Then, the UPPAAL tool is used to simulate and analyse the behavior of the system. The process is illustrated with a case study, an airline ticket reservation system. The example shows the systematic translation process, and the resulting model is checked for a suite of rather generic safeness and liveness properties.

Lecture Notes in Computer Science, 2009

Web services are distributed software components, that are decoupled from each other using interfaces with specified functional behaviors. However, such behavioral specifications are insufficient to demonstrate compliance with certain temporal non-functional policies. An example is demonstrating that a patient's health-related query sent to a health care service is answered only by a doctor (and not by a secretary). Demonstrating compliance with such policies is important for satisfying governmental privacy regulations. It is often necessary to expose the internals of the web service implementation for demonstrating such compliance, which may compromise modularity. In this work, we provide a language design that enables such demonstrations, while hiding majority of the service's source code. The key idea is to use greybox specifications to allow service providers to selectively hide and expose parts of their implementation. The overall problem of showing compliance is then reduced to two subproblems: whether the desired properties are satisfied by the service's greybox specification, and whether this greybox specification is satisfied by the service's implementation. We specify policies using LTL and solve the first problem by model checking. We solve the second problem by refinement techniques.

2014

It is widely recognized that temporal aspects are indispensable for Web Service modeling. Unfortunately, the current Semantic web Services description languages suffer from the lack of useful concepts needed for timing description. For this purpose, we propose a global methodology for the specification of timing behavior with an extended OWL-S ontology and verification of temporal properties with UPPPAL tool. The applicability is illustrated through the multimodal transport use case.

2005

In this paper we show how we can use formal methods for describing and analyzing the behavior of Web Services, and more specifically those including time restrictions. Then, our starting point are Web Services descriptions written in WSCI -WSCDL (XML-based description languages). These descriptions are then translated into timed automata, and then, we use a well known tool that supports this formalism (UPPAAL) to simulate and analyze the system behavior. As illustration we take a particular case study, a travel reservation system.

Web Services, 2009. …, 2009

Current Web service composition approaches and languages such as WS-BPEL do not allow to define temporal constraints in a declarative and separate way. Also it is not possible to verify if there are contradictions between the temporal constraints implemented in the composition. These limitations lead to maintainability and correctness problems. In this paper, we tackle these problems through a novel approach to temporal constraints in Web service compositions, which combines formal methods and aspect-oriented programming. In this approach, we use a powerful and expressive formal language, called XTUS-Automata, for specifying time-related properties and we introduce specification patterns that ease the definition of such constraints. The formal specifications are translated automatically into AO4BPEL aspects, which ensure the runtime monitoring of the temporal constraints. Our approach enables a declarative, separate, and verifiable specification of temporal properties and it generates automatically modular enforcement code for those properties.

2006

This work presents a new approach to the analysis and verification of the time requirements of Web Services compositions via goal-driven models and model checking techniques. The goal-driven model used is an extension of the goal model KAOS and the model checker engine is the UPPAAL tool. The goal model specifies the properties that the system must satisfy and how they should be verified by using the model checker engine. In order to illustrate this approach, we apply these techniques to a basic Internet purchase process.

Service Oriented Software Engineering, 2006

Web services provide a language-neutral, loosely-coupled, and platform independent way for linking applications within organizations or enterprises across the Internet. Web services communicate with each other via XML format messages. This paper presents a web service architecture model, Service-Oriented Software Architecture Model (SO-SAM), which is an extension of SAM (Software Architecture Model ) to the web service applications, as well as a validation of the model and a case study. SO-SAM is an executable architectural model incorporating Predicate Transition Nets with the style and understandability of component-based concepts. SO-SAM describes each web service in terms of component and service composition in terms of connector separately. We believe that SO-SAM facilitates the verification and monitoring of web services integration since SO-SAM fits the distributed nature of modern composite web services. In order to validate the model against system properties, we rewrite the SO-SAM into the XML format, and validate SO-SAM using a SAM support tool, SAM parser. Finally, a case study of the validation of the model is demonstrated.