Model-driven Development of Web Service Transactions

Web service technologies are becoming increasingly important for integrating systems and services. There is much activity and interest around standardization and usage of Web service technologies. Contemporary Web services are described in the Web Service Description Language (WSDL). However, WSDL documents can be difficult to understand for service developers. This article recommends a model-driven process for Web service development combining the graphical modeling language UML with WSDL. The Unified Modeling Language (UML) is developed by Object Management Group. In the proposed process, Web service descriptions (in WDSL) are converted to UML; their UML models are integrated to form composite Web services; and then the new Web service descriptions are exported. The main contribution of this article is a “pure UML” modeling strategy supported by implementation of two-way conversion rules between the UML models and the WSDL documents.

The vision of the Semantic Web is to reduce manual discovery and usage of Web resources (documents and services) and to allow software agents to automatically identify these Web resources, integrate them and execute them for achieving the intended goals of the user. Such a composed Web service may be represented as a workflow, called service flow. Current studies of Web services are not sufficient for automatic composition. This paper presents different types of compositional knowledge required for Web service discovery and composition: syntactic, semantic and pragmatic knowledge. As a proof of concept, we have implemented our framework in a cardiovascular domain which requires advanced service discovery and composition across heterogeneous platforms of multiple organizations. Within this framework, we describe (1) How to represent the compositional knowledge, which plays a role in service discovery and composition, in DAML-S; (2) How heterogeneous medical services intemperate in a composed medical service flow. (3) To solve this knowledge level integration, we build on an ontology integration method called SEMIO (Semantic Interoperability).

Nowadays, software effort estimation plays an important role in software project management due to its extensive use in industry to monitor progress, and performance, determine overall productivity and assist in project planning. After the success of methods such as IFPUG Function Point Analysis, MarkII Function Point Analysis, and COSMIC Full Function Points, several other extension methods have been introduced to be adopted in software projects. Despite the efficiency in measuring the software cost, software effort estimation, unfortunately, is facing several issues; it requires some knowledge, effort, and a significant amount of time to conduct the measurement, thus slightly ruining the advantages of this approach. This paper demonstrates a functional size measurement tool, named UML Point tool, that utilizes the concept of IFPUG Function Point Analysis directly to Unified Modeling Language (UML) model. The tool allows the UML eXchange Format (UXF) file to decode the UML model of mobile game requirement and extract the diagrams into component complexity, object interface complexity, and sequence diagram complexity, according to the defined measurement rules. UML Point tool then automatically compute the functional size, effort, time, human resources, and total development cost of mobile game. Besides, this paper also provides a simple case study to validate the tool. The initial results proved that the tool could be useful to improve estimation accuracy for mobile game application development and found to be reliable to be applied in the mobile game industry.

In highly collaborative business contexts, services design is even more important than in other contexts, as services are more complex and involve multiple and composed services. Such contexts are ideal for service composition and thus service reuse. This paper presents an ongoing research project whose goal is to support the design of such services by reconciling different viewpoints, following a model-driven approach. It focuses on the so-called “transactional aspects” of the service design, corresponding to the processes realizing the service and showing services compositions between the involved parties. It is applied to a case study in the construction sector.

Objective: Our purpose is to propose the guideline for developing web services components from HL7 (Health Level 7) standard. Methods: All business processes describing in HL7 are modeled using UML (Unified Modeling Language). Both UML diagrams and web services profiles can be presented with XML (Extensible Markup Language). Therefore we suggest a framework to derive web services from HL7 standards semi-automatically. Results: We show that skeletal XML documents for web services can be generated from HL7 standards. Additionally we propose a way to program with Java for web services using given web service profiles. Conclusion: This paper presents the methodology of developing HL7-compatible electronic health record systems using web services. (Journal of Korean Society of Medical Informatics 13-4, 361-374, 2007)

”Al-Barokah Smart House” is an education house for society with some of the main goals to increase interest in reading, developing children intelligent potential, technology introduction by learning in 4 center. One of the subject taught in elementary school curriculum is Natural Science, which related to learning about nature systematically, so that this subject is no longer about mastery of knowledge in the form of a collection of facts, concepts, or principles, but also a process of discovery in which initially abstract and becomes concrete in later stage. One of the lesson learned in the fourth grade is “Motion Energy due to air alteration”. AR (Augmented Reality) is a term for an environment created by the computer that combines real world and virtual world so that there the boundary between these two become indiscrete. Utilizing AR (Augmented Reality) technology, the learning process of plane movement can be simulated into 3D form so that the movement of plane and windmills can be seen realistically. This application is designed with UML (Unified Modeling Language) modeling, which consists of Use Case Diagram, Activity Diagram and Sequence Diagram, also Storyboard implemented using Adobe Flash CS6. This application is expected to enhance students' understanding and make the learning process be more creative and interactive. Keywords: natural science, elementary school, UML, augmented reality, wind energy

We propose in this paper a model-driven approach for specifying and verifying Web services composition. In particular, we present how the process engineering and reengineering allows us to check the consistency of Web services composition. To achieve this goal, we based on the Architecture Description Language (ADL) ACME. This ADL is coupled to Armani, a formal language based on first order predicates. Using MDE tools such as ATL, Xtext, Xpand and Check, we have developed a tool WSC2ACME taking as input a textual WSDL specification and outputting the corresponding ACME code. Then, we propose the re-engineering of the process to be able to use it properly, and to ensure the proper functioning of the Web services composition. Our approach aims at improving the existing proposals taking a step forward in simplifying and improving the reliability of service composition.

The article describes a method for developing and modelling composite web-services. Web-service composition is used to derive new functionality from the interaction of existing web-services. Composite web-services are built in several stages: specifications (determining the type of service); development of the structure of the service based on the algebra of services; service composition modelling; selecting a service variant and generating a service. The main elements of the proposed approach are the algebra of services and web-services interaction models (basic and composite). The above approach formally presents the consideration of the main aspects in solving problems related to the construction of effective composite web-services and the selection of mathematical models, namely: description of web-services, determining the structure of web-services, taking into account the dynamics of information changes, taking into account the main uncertainties in building the structure web-services. Based on the approach, a method for constructing composite web-services has been developed. The method is based on an algebraic description of a web-service based on a specialized algebra of services. The method consists of the following steps: description of the task of developing a web-service; development of the structure of a web service based on the algebra of services; formal description of the structure and clarification of service operations; building models of functioning and interaction of service components; building simulation models of the composite service; defining the final structure of the composite service; web-service implementation. The main tool for describing composite services is the algebra of services, and the model building tool is colouredPetri nets implemented using СPN Tools. As an example of the application of the developed method, the construction of a pharmaceutical service is described, in which the modellingof the interaction of web-services based on Petri nets is used. The process of building a composite model of a web-service is considered. The process begins with building a pharmaceutical web-service model structure based on the service algebra. Based on the service algebra, operators were developed to implement composite services. The structure of the model is developed, which is presented in the form of a formal description. The process of building pharmaceutical service models in the СPN Tools environment is described in detail.

THE Internet, along with its related technologies, has created an interconnected world in which information flows easily and tasks are processed collaboratively. To make service-oriented applications more robust, Web services must be examined from a transactional perspective. By transactional, we mean first defining the actions that guide the execution of Web services when failures arise and then the states that permit claiming the success of this execution following the handling of these failures. A variety of transactional models are reported in the database community. Some of these models can be leveraged and enhanced in response to Web services characteristics while others are not suitable for Web services due to the dynamic nature of Web services, the long-running execution scenarios that Web services take part in, and the successful execution of Web services despite other peers’ failure. Today’s service-oriented applications require advanced transactional models that guarantee integrity and continuity of business processes despite the dynamic nature of the features of the environments hosting the execution of these applications. This special section sheds light on the latest advances in the fields of Web services and transactional models in order to better address advanced research on and experience with transactional Web services. Four papers out of 19 submissions were selected for inclusion in this special section. Each submission was subject to a double-review process by at least three peer reviewers. In the first paper, entitled “Event-Based Design and Runtime Verification of Composite Service Transactional Behavior,” Gaaloul et al. propose an event-driven approach to validate the transactional behavior of Web services taking part in compositions. A composition life cycle consists of four phases, namely, design, execution, monitoring, and reengineering. The verification of this behavior throughout this life cycle is done either at design time to validate recovery mechanisms’ consistency or after runtime to detect execution deviations and repair design errors, and, therefore, formally ensure the execution reliability of Web services. In addition, this verification is based on the Event Calculus formalism, which offers a sound definition for this reliability. In the second paper, entitled “FACTS: A Framework for Fault-Tolerant Composition of Transactional Web Services,” Liu et al. note that delivering reliable compositions over unreliable Web services is challenging. To address this challenge, Liu et al. identify a set of high-level exception handling strategies and a new taxonomy of transactional Web services to devise a fault-tolerant mechanism that combines exception handling and transaction techniques. In addition, Liu et al. devise two modules, known as specification and verification, to assist service designers in constructing fault handling logic conveniently and correctly. This logic is automatically injected into WS-BPEL. In the third paper, entitled “Rule-Based Coordination of Distributed Web Service Transactions,” von Riegen et al. study the distributed transactional activity control problem in the context of service choreographies. In such a context, many participants are allowed to work together to achieve a global, common goal, and the initiator of a process is not always the one who is able to commit or cancel a transaction. Von Riegen et al. introduce a framework that allows autonomous coordination of dynamic processes. This framework extends WSBusinessActivity to strengthen the role of the coordinator. Predicate rules are developed to let participants cancel or complete a process and help the coordinators decide on the completion processes and the confirmation or cancellation of the participants’ works. In the fourth paper, entitled “TQoS: Transactional and QoS-Aware Selection Algorithm for Automatic Web Service Composition,” El Haddad et al. focus on the issues of selecting and composing Web services. A design-time selection algorithm is proposed in which transactional and QoS requirements are both integrated into the selection process. This algorithm is based on the notion of risk that indicates if execution outcomes can either be compensated for or not. Two risk levels of execution in a transactional system are considered: Risk 0, meaning that if the execution is successful, the obtained outcomes can be compensated for by the user, and Risk 1, meaning that the system does not guarantee successful execution, but if it achieves it, the outcomes cannot be compensated for by the user. We hope this special section inspires researchers to develop new transactional models that would guarantee service-oriented applications integrity and continuity. 30 IEEE TRANSACTIONS ON SERVICES COMPUTING, VOL. 3, NO. 1, JANUARY-MARCH 2010

Grid applications are increasingly being developed as workflows built of well-structured, reusable components. We develop a user-transparent scheduling approach for Higher-Order Components (HOCs) . parallel implementations of typical programming patterns, accessible and customizable via Web services. We introduce a set of cost functions for a reusable scheduling: when the workflow recurs, it is mapped to the same execution nodes, avoiding the need for a repeated scheduling phase. We prove the efficiency of our scheduling by implementing it within the KOALA scheduler and comparing it with KOALA's standard Closeto- File policy. Experiments on scheduling HOC-based applications achieve a 40% speedup in communication and a 100% throughput increase.

A web service is a software system that supports interoperable machine to machine interaction over the network. It can be any kind of service provided on the web that can exchange data between applications. In simple terms, it is any program that is callable by another program across the web using standard protocols. Web services are special because they are independent of the platform, programming language, and model design. In current web applications, more businesses are gradually publishing their business as services over the web. This growing number of web services available within an organization and on the Web raises a new and challenging search problem: locating desired web services. Searching for web services with conventional web search engines is insufficient in this context. In this paper, a latent semantic web service discovery and composition framework, addressing both discovery and composition of web services, is introduced. The framework provides a graphical visualization interface that can facilitate users in finding the desired web service beyond the general keyword search and provide composition of complex services if the service does not exist. A novel approach based on an information retrieval technique known as latent semantic analysis is applied to a large web service descriptions data set collection. By using co-occurrence patterns across the entire data collection, and then using those patterns to infer semantic relationships between documents, relevant results in a ranked order can be retrieved. Moreover, a back to front algorithm is applied to the composition search interface in order to compose complex web services in full or partial terms from pre-existing web services when the requested service does not exist. An experimental study conducted on a collection of 2525 publicity available web service shows improved performance to the technique applied in obtaining much better search results.

Service Oriented Architecture (SOA) introduced the web services as distributed computing components that can be independently deployed and invoked by other services or software to execute composite services that represent an end-to-end business process. An important problem in the SOA is the web service selection and composition problem which involves selecting the right web services mix to construct the best service composition that achieves the consumers Service Level Agreement (SLA) requirements. In this chapter we propose different methods to solve the problem of the business processes execution engine web service selection and services composition construction in the Service Oriented Architecture (SOA).  The chapter provides different mechanisms to improve the web services selection and composition using dynamic techniques. The main goal is to satisfy the services' requirements expressed as the SLA and to enhance the services selection and composition by increasing the availability and decreasing the response time of the service compositions.

The automatic composition of Web services requires the existing services to be encoded in a semantic form, such as ontology. If Web services are represented with ontology, we can automatic compose Web services by means of their semantics. Ontology modeling is divided into two steps: input/output parameters modeling and Web services modeling. First, we collect Web services' input/output parameters, represent them with classes in ontology, and transform Web services to properties in ontology, define relations between classes and properties. Then we judge Web services' relations based on relations between properties transformed from these Web services and estimate whether these Web services can be composed.

The Business Process Execution Language (BPEL) has become the standard in Web service composition, so that been adopted by industries to create mission critical services. The business process reliability especially business process consistency when some services failed is critical to composite services especially involving various organizations. However, it is difficult to conduct business process reliability testing for composite services due to complex business process in service composition, remote deployed services and long time testing duration. Little research is done to test fault tolerance capabilities of composite services only from low level. This paper proposes a technique on how to test the reliability of composite service defined in BPEL from the view of business semantics with little cost using fault injection. We present an approach for reliability testing of web services by using service stubs with semantic faults instead of real services which can be placed at service provider side or service consumer side. Dislike existing studies, we focus on how to find the reliability problems associating with business process - called semantics as the problems are not pure coding error but faults related to business process. In addition, the behavior of composite services in BPEL is analyzed when there are faults in orchestrated services invoked. Finally, a case study is given to show the whole process of reliability testing for composite web service.

Within this thesis, a workflow for an efficient and practical handling of spatio-temporal data is presented. This workflow consists of three layered parts. The first part is the efficient management of spatio-temporal data. The second part focuses on the development of Web services for the dissemination of spatio-temporal data. The third part is a generic mobile GIS for professional users as a typical application for the spatio-temporal data management model and the related Web services.