55,783 research outputs found

    Correctness of services and their composition

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    We study correctness of services and their composition and investigate how the design of correct service compositions can be systematically supported. We thereby focus on the communication protocol of the service and approach these questions using formal methods and make contributions to three scenarios of SOC.Wir studieren die Korrektheit von Services und Servicekompositionen und untersuchen, wie der Entwurf von korrekten Servicekompositionen systematisch unterstützt werden kann. Wir legen dabei den Fokus auf das Kommunikationsprotokoll der Services. Mithilfe von formalen Methoden tragen wir zu drei Szenarien von SOC bei

    Correctness of services and their composition

    Get PDF
    We study correctness of services and their composition and investigate how the design of correct service compositions can be systematically supported. We thereby focus on the communication protocol of the service and approach these questions using formal methods and make contributions to three scenarios of SOC.Wir studieren die Korrektheit von Services und Servicekompositionen und untersuchen, wie der Entwurf von korrekten Servicekompositionen systematisch unterstützt werden kann. Wir legen dabei den Fokus auf das Kommunikationsprotokoll der Services. Mithilfe von formalen Methoden tragen wir zu drei Szenarien von SOC bei

    A Service-Based Component Model: Formalism, Analysis and Mechanization

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    Component-Based Software Engineering (CBSE) is one of the approaches to master the development of large scale software. In this setting, the verification concern is still a challenge. The objective of our work is to provide the designer of components-based systems with the methods to assist his/her use of the components. In particular, the current work adresses the composability of components and their services. A component model is presented, based on services. An associated simple but expressive formalism is introduced; it describes the services as extended LTS and their structuring as components. The composition of components is mainly based on service composition and encapsulation. The composability of component is defined from the composability of services. To ensure the correctness of component composition, we check that an assembly is possible via the checking of the composabiblity of the linked services, and their behavioral compatibility. In order to mechanize our approach, the services and the components are translated into the MEC and LOTOS formalism. Finally the MEC and LOTOS CADP toolbox is used to perform experiments

    A Linear Logic approach to RESTful web service modelling and composition

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    A thesis submitted to the University of Bedfordshire in partial fulfilment of the requirements for the degree of Doctor of PhilosophyRESTful Web Services are gaining increasing attention from both the service and the Web communities. The rising number of services being implemented and made available on the Web is creating a demand for modelling techniques that can abstract REST design from the implementation in order better to specify, analyse and implement large-scale RESTful Web systems. It can also help by providing suitable RESTful Web Service composition methods which can reduce costs by effi ciently re-using the large number of services that are already available and by exploiting existing services for complex business purposes. This research considers RESTful Web Services as state transition systems and proposes a novel Linear Logic based approach, the first of its kind, for both the modelling and the composition of RESTful Web Services. The thesis demonstrates the capabilities of resource-sensitive Linear Logic for modelling five key REST constraints and proposes a two-stage approach to service composition involving Linear Logic theorem proving and proof-as-process based on the π-calculus. Whereas previous approaches have focused on each aspect of the composition of RESTful Web Services individually (e.g. execution or high-level modelling), this work bridges the gap between abstract formal modelling and application-level execution in an efficient and effective way. The approach not only ensures the completeness and correctness of the resulting composed services but also produces their process models naturally, providing the possibility to translate them into executable business languages. Furthermore, the research encodes the proposed modelling and composition method into the Coq proof assistant, which enables both the Linear Logic theorem proving and the π-calculus extraction to be conducted semi-automatically. The feasibility and versatility studies performed in two disparate user scenarios (shopping and biomedical service composition) show that the proposed method provides a good level of scalability when the numbers of services and resources grow

    Multilevel Contracts for Trusted Components

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    This article contributes to the design and the verification of trusted components and services. The contracts are declined at several levels to cover then different facets, such as component consistency, compatibility or correctness. The article introduces multilevel contracts and a design+verification process for handling and analysing these contracts in component models. The approach is implemented with the COSTO platform that supports the Kmelia component model. A case study illustrates the overall approach.Comment: In Proceedings WCSI 2010, arXiv:1010.233

    Can Component/Service-Based Systems Be Proved Correct?

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    Component-oriented and service-oriented approaches have gained a strong enthusiasm in industries and academia with a particular interest for service-oriented approaches. A component is a software entity with given functionalities, made available by a provider, and used to build other application within which it is integrated. The service concept and its use in web-based application development have a huge impact on reuse practices. Accordingly a considerable part of software architectures is influenced; these architectures are moving towards service-oriented architectures. Therefore applications (re)use services that are available elsewhere and many applications interact, without knowing each other, using services available via service servers and their published interfaces and functionalities. Industries propose, through various consortium, languages, technologies and standards. More academic works are also undertaken concerning semantics and formalisation of components and service-based systems. We consider here both streams of works in order to raise research concerns that will help in building quality software. Are there new challenging problems with respect to service-based software construction? Besides, what are the links and the advances compared to distributed systems?Comment: 16 page

    Modal logics for reasoning about object-based component composition

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    Component-oriented development of software supports the adaptability and maintainability of large systems, in particular if requirements change over time and parts of a system have to be modified or replaced. The software architecture in such systems can be described by components and their composition. In order to describe larger architectures, the composition concept becomes crucial. We will present a formal framework for component composition for object-based software development. The deployment of modal logics for defining components and component composition will allow us to reason about and prove properties of components and compositions

    Stochastic models for quality of service of component connectors

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    The intensifying need for scalable software has motivated modular development and using systems distributed over networks to implement large-scale applications. In Service-oriented Computing, distributed services are composed to provide large-scale services with a specific functionality. In this way, reusability of existing services can be increased. However, due to the heterogeneity of distributed software systems, software composition is not easy and requires additional mechanisms to impose some form of a coordination on a distributed software system. Besides functional correctness, a composed service must satisfy various quantitative requirements for its clients, which are generically called its quality of service (QoS). Particularly, it is tricky to obtain the overall QoS of a composed service even if the QoS information of its constituent distributed services is given. In this thesis, we propose Stochastic Reo to specify software composition with QoS aspects and its compositional semantic models. They are also used as intermediate models to generate their corresponding stochastic models for practical analysis. Based on this, we have implemented the tool Reo2MC. Using Reo2MC, we have modeled and analyzed an industrial software, the ASK system. Its analysis results provided the best cost-effective resource utilization and some suggestions to improve the performance of the system.UBL - phd migration 201
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