Distribution pattern-driven development of service architectures

Distributed systems are being constructed by composing a number of discrete components. This practice is particularly prevalent within the Web service domain in the form of service process orchestration and choreography. Often, enterprise systems are built from many existing discrete applications such as legacy applications exposed using Web service interfaces. There are a number of architectural configurations or distribution patterns, which express how a composed system is to be deployed in a distributed environment. However, the amount of code required to realise these distribution patterns is considerable. In this paper, we propose a distribution pattern-driven approach to service composition and architecting. We develop, based on a catalog of patterns, a UML-compliant framework, which takes existing Web service interfaces as its input and generates executable Web service compositions based on a distribution pattern chosen by the software architect

Investigations into the model driven design of distribution patterns for web service compositions

Increasingly, distributed systems are being used to provide enterprise level solutions with high scalability and fault tolerance These solutins are often built using Web servces that are composed to perform useful business functions Acceptance of these composed systems is often constrained by a number of non-functional properties of the system such as availability, scalability and performance There are a number of drstribution patterns that each exhibit different non-functional charactmstics These patterns are re-occuring distribution schemes that express how a system is to be assembled and subsequently deployed. Traditional approaches to development of Web service compositions exhibit a number of Issues Firstly, Web service composition development is often ad-hoc and requires considerable low level coding effort for realisatlon Such systems often exhibit fixed architectures, making maintenance difficult and error prone Additionally, a number of the non-funchonal reqwements cannot be easily assessed by exammng low level code. In this thesis we explicitly model the compositional aspects of Web service compositions usmg UML Activity diagrams Ths approach uses a modehng and transformation framework, based on Model Dnven Software Development (MDSD), going from high level models to an executable system The framework is guided by a methodological framework whose primary artifact is a distribution pattern model, chosen from the supplied catalog. Our modelling and transfomation framework improves the development process of Web service compositions, with respect to a number of criteria, when compared to the traditional handcrafted approach Specifically, we negate the coding effort traditionally associated with Web service composition development Maintenance overheads of the solution are also slgnificantly reduced, while improved mutability 1s achieved through a flexible architecture when compared with existing tools We also improve the product output from the development process by exposing the non-functional runtime properties of Web service compositlons using distribution patterns

FLACOS’08 Workshop proceedings

The 2nd Workshop on Formal Languages and Analysis of Contract-Oriented Software (FLACOS’08) is held in Malta. The aim of the workshop is to bring together researchers and practitioners working on language-based solutions to contract-oriented software development. The workshop is partially funded by the Nordunet3 project “COSoDIS” (Contract-Oriented Software Development for Internet Services) and it attracted 25 participants. The program consists of 4 regular papers and 10 invited participant presentations

Multi-agent communication for the realization of business-processes

As Internet and information technologies expand further into daily business activities, new solutions and techniques are required to cope with the growing complexity. One area that has gained attention is systems and organizations interoperability and Service Oriented Architectures (SOA). Web Services have grown as a preferred technology in this area. Although these techniques have proved to solve problems of low level integration of heterogeneous systems, there has been little advance at higher levels of integration like how to rule complex conversations between participants that are autonomous and cannot depend on some ruling or orchestrating system. Multi-agent technology has studied techniques for content-rich communication, negotiation, autonomous problem solving and conversation protocols. These techniques have solved some of the problems that emerge when integrating autonomous systems to perform complex business processes. The present research work intends to provide a solution for the realization of complex Business Process between heterogeneous autonomous participants using multi-agent technology. We developed an integration of Web Services and agent-based technologies along with a model for creating conversation protocols that respect the autonomy of participants. A modeling tool has been developed to create conversation protocols in a modular and reusable manner. BDI-Agents implementations that communicate over Web Services are automatically generated out of these models.Internet und Informationstechnik finden immer mehr Verwendung in alltäglichen Geschäftsaktivitäten und als Folge dessen, werden neue Lösungen und Verfahren gebraucht, um der steigenden Komplexität gerecht zu werden. Insbesondere Bereiche wie System- und Organizations- Interoperabilität, wie auch dienst-orientierte Architekturen (SOA) haben demzufolge mehr Aufmerksamkeit bekommen. Dabei sind Web Services zur bevorzugten Technologie geworden. Tatsächlich haben diese Techniken Probleme in niedrigeren Ebenen gelöst, die beim lntegrieren von heterogenen Systemen entstehen. Allerdings gab es bisher weniger Fortschritte in höheren Ebenen, wie der Regelung von komplexen Dialogen zwischen Teilnehmern, die aufgrund ihrer Autonomie, sich nicht nach anderen kontrollierenden oder orchestrierenden Systemen richten lassen. Multiagenten-Systeme haben Bereiche wie inhaltreiche Kommunikation, Handel, autonome Problemlösung und Interaktionsprotokolle im Detail geforscht. Diese Techniken haben Probleme gelöst, die beim Ausführen von komplexen Geschäftsprozessen auftreten. Die vorliegende Doktorarbeit beabsichtigt, mit Verwendung von Multiagenten-Technologien, eine Lösung für die Umsetzung von komplexen Geschäftsprozessen zwischen heterogenen autonomen Teilnehmern bereitzustellen. Wir haben eine Integrationslösung für Web Services und agenten-basierte Technologien zur Verfügung gestellt, zusammen mit einem Model für die Erstellung von Interaktions-Protokollen, die die Autonomie der Teilnehmer berücksichtigt. Ein Modellierungstool wurde entwickelt, um modulare und wiederverwendbare Interaktionsprotokolle gestalten zu können. Aus diesen Modellen kann man auch Implementierungen automatisch erzeugen lassen, welche BDI-Agenten, die über Web Services kommunizieren, verwenden

A business-oriented framework for enhancing web services security for e-business

Security within the Web services technology field is a complex and very topical issue. When considering using this technology suite to support interacting e-businesses, literature has shown that the challenge of achieving security becomes even more elusive. This is particularly true with regard to attaining a level of security beyond just applying technologies, that is trusted, endorsed and practiced by all parties involved. Attempting to address these problems, this research proposes BOF4WSS, a Business-Oriented Framework for enhancing Web Services Security in e-business. The novelty and importance of BOF4WSS is its emphasis on a tool-supported development methodology, in which collaborating e-businesses could achieve an enhanced and more comprehensive security and trust solution for their services interactions. This investigation began with an in-depth assessment of the literature in Web services, e-business, and their security. The outstanding issues identified paved the way for the creation of BOF4WSS. With appreciation of research limitations and the added value of framework tool-support, emphasis was then shifted to the provision of a novel solution model and tool to aid companies in the use and application of BOF4WSS. This support was targeted at significantly easing the difficulties incurred by businesses in transitioning between two crucial framework phases. To evaluate BOF4WSS and its supporting model and tool, a two-step approach was adopted. First, the solution model and tool were tested for compatibility with existing security approaches which they would need to work with in real-world scenarios. Second, the framework and tool were evaluated using interviews with industry-based security professionals who are experts in this field. The results of both these evaluations indicated a noteworthy degree of evidence to affirm the suitability and strength of the framework, model and tool. Additionally, these results also act to cement this thesis' proposals as innovative and significant contributions to the research field

A Programming Language for Web Service Development

There is now widespread acceptance of Web services and service-oriented architectures. But despite the agreement on key Web services standards there remain many challenges. Programming environments based on WSDL support go some way to facilitating Web service development. However Web services fundamentally rely on XML and Schema, not on contemporary programming language type systems such as those of Java or .NET. Moreover, Web services are based on a messaging paradigm and hence bring forward the traditional problems of messaging systems including concurrency control and message correlation. It is easy to write simple synchronous Web services using traditional programming languages; however more realistic scenarios are surprisingly difficult to implement. To alleviate these issues we propose a programming language which directly supports Web service development. The language leverages XQuery for native XML processing, supports implicit message correlation and has high level join calculus-style concurrency control. We illustrate the features of the language through a motivating example

Modeling and using business collaborations

Abstract. Business processes interact with each other by sending and receiving messages; how such interactions take place (i.e. in which order and with which timing constraints) has to be defined in advance with a collaboration model, so the parties can be developed separately in conformity with it. With orchestration languages, however, the role of a collaboration model is that of an interface, so it is the run-time responsibility of the activities of the business process to guarantee that messages are exchanged in proper order and time. This paper motivates the need of run-time collaboration instances, which, by keeping the state of ongoing collaborations, relieve business processes of the burden of checking the conformity of the actual operations with the collaboration model. Moreover this paper presents a software environment, called bProgress, which we have developed so as to experiment with business processes and collaboration ones