Development Of Service-oriented Applications Research Articles

The LRA Workbench: an IDE for efficient REST API composition through linked metadata

The number of Web APIs for accessing information and services is continuously increasing, and yet, no tools exist to automate the time-consuming and error-prone process of invoking those APIs and composing their responses. The recent emergence of widely-adopted, standardized, Web-API description formats and the development of Linked Data technologies for data integration have motivated our work on the LRA (Linked REST APIs) methodology [1, 2]. LRA relies on RDF service specifications to automate the development process around the usage of Web APIs. This automation represents a great opportunity to systematize and improve the quality of service-oriented application development. However, LRA’s reliance on SPARQL as the user-interaction model may hinder its adoption, because it requires developers to learn the intricacies of the unconventional graph data model and its associated datasets. In this paper we have developed the LRA Workbench (LRA_{Wbench}), which takes advantage of the emergent schema of Web-API specifications, in order to simplify the formulation of LRA-compliant SPARQL queries. Our empirical evaluation of the LRA_{Wbench} usability demonstrates that our tool significantly improves the performance of developers formulating SPARQL queries for LRA. A subsequent study on the effectiveness of the LRA_{Wbench} demonstrated that developers using LRA tend to produce code with considerable better structural complexity, in less time, than developers manually composing APIs.

Amplification of Availability in Web Services by Earlier Detection of False Requests during Service-oriented Application Development

Amplification of Availability in Web Services by Earlier Detection of False Requests during Service-oriented Application Development

A reference model of services computing systems platform based on meta-analysis technique

The development of services computing systems requires an environment that supports service-oriented application development approach. The organized environment is referred to as platform in this paper. The lack of such generic platform is a challenge in the field. A reference model becomes a prerequisite for developing such platform in order to optimize the computing resources. This paper proposes a reference model of services computing systems platform based on the literature studies using a meta-analysis technique. The paper demonstrates a reference model development using the systematic meta-analysis technique to identify the required components of the platform and to examine the interaction between the components. Statistical tests are conducted to show the correlation between the components and to evaluate the proposed reference model. This study also discusses the different functions and areas for each layer of the proposed model. The contribution of this paper is a generic reference model of services computing systems platform based on meta-analysis technique that can be used as a guide to build the platform.

Smart Spaces-Based Application Development

Smart spaces form now an emerging paradigm for application development in the various domains of ubiquitous, pervasive, mobile, embedded, and edge-centric computing. The smart space-based development still lacks matured methodologies appropriate for a wide range of application domains. The authors consider a particular class of smart spaces where interaction of many participants is information-driven and ontology-oriented using the indirect interaction models from multi-agent systems and knowledge manipulation technologies from the Semantic Web. The paper summarizes more than ten years of the authors' experience for this class of smart space-based application development. The M3 architecture (multidevice, multivendor, multidomain) for smart spaces enables concept development of service-oriented applications based on information sharing by software agents running on various devices and acting as knowledge processors. The Smart-M3 platform is an open source solution that implements the M3 architecture.

Enhancing service discovery using cat swarm optimisation based web service clustering

Summary Web service discovery is a critical task in service oriented application development. Due to extensive proliferation in the number of available services, it is challenging to obtain all the relevant services available for a given task. For the retrieval of most relevant Web services, a user would have to use those service-specific terms that best describe and match the natural language documentation contained within a service description. This process can be time intensive, due to functional diversity of available services in a repository. Domain specific clustering of Web Services based on the similarities of their functionalities would greatly boost the ability of a Web service search engine to retrieve the most relevant service. In this paper, we propose a novel technique to cluster service documents into functionally similar service groups using the Cat Swarm Optimisation Algorithm. We present experimental results that show that the proposed technique was effective and enhanced the process of service discovery.

Variability modeling to develop flexible service-oriented applications

To cope with requirement changes flexibly and rapidly, the existing component-based paradigm is being evolved into a service-oriented computing paradigm. The main characteristic of the service-oriented computing paradigm is that service-oriented applications are developed as loosely coupled services that reflect business concerns. This paradigm also promotes business agility, facilitating quick reactions to business changes. Therefore, to enhance and support the benefits of the service-oriented computing paradigm, we must consider how to improve flexibility and reusability during the development of service-oriented applications. We propose the variability modeling approach to specify and control the common and distinguishing characteristics of service-oriented applications. That is, the key concepts of product-line technology can be used to make service-oriented applications more flexible and reusable. This paper describes variability modeling at two levels; the composition level and the specification level. At the composition level, we describe the variability of composition and the flow of domain services that fulfill business processes. At the specification level, we present a domain service that is an abstract service with variability. The use of our systematic variability modeling approach can greatly increase the flexibility, applicability, and reusability of service-oriented applications.

Connectors as designs: Modeling, refinement and test case generation

Over the past years, the need for high-confidence coordination mechanisms has intensified as new technologies have appeared for the development of service-oriented applications, making formalization of coordination mechanisms critical. Unifying Theories of Programming (UTP) provide a formal semantic foundation not only for programming languages but also for various expressive specification languages. A key concept in UTP is design: the familiar pre/post-condition pair that describes a contract. In this paper we use UTP to formalize Reo connectors, whereby connectors are interpreted as designs in UTP. This model can be used as a semantic foundation for proving properties of connectors, such as equivalence and refinement relations between connectors. Furthermore, it can be used as a reference document for developing tool support for Reo, such as test case generators. A fault-based method to generate test cases for component connectors from specifications is also provided in this paper. For connectors, faults are caused by possible errors during the development process, such as wrongly used channels, missing or redundant subcircuits, or circuits with wrongly constructed topology. We give test cases and connectors a unifying formal semantics by using the notion of design in UTP, and generate test cases by solving constraints obtained from a specification and a faulty implementation. A prototype serves to demonstrate the automatization of the approach.

Connectors as Designs

The complex interactions that appear in service-oriented computing make coordination a key concern in service-oriented systems. Over the past years, the need for high-confidence coordination mechanisms has intensified as new technologies have appeared for the development of service-oriented applications, making formalization of coordination mechanisms critical. Unifying Theories of Programming (UTP) provide a formal semantic foundation not only for programming languages but also for various expressive specification languages. A key concept in UTP is design: the familiar pre/post-condition pair that describes the contract. In this paper we use UTP to formalize Reo connectors, whereby connectors are interpreted by designs in UTP. This model can be used as a reference document for developing tool support for Reo, such as a test case generator. It can also be used as a semantic foundation for proving properties of connectors, such as equivalence and refinement relations between connectors.

QoS-Driven Service Selection and Composition Using Quantitative Constraint Automata

Assuring Quality of Service (QoS) properties is critical in Service-Oriented Application (SOA) development. In this paper, we present an approach for specifying the QoS properties of services along multiple dimensions and selecting services for their composition in a way that optimizes the QoS of the result. We apply the integration of concerns paradigm to allow combined specification of QoS and functional properties by using Quantitative Constraint Automata, which integrate QoS aspects into service-oriented application development processes, mainly for service selection and composition.