Generación dinámica de invariantes para composiciones de servicios web en WS-BPEL

En los últimos años, las arquitecturas orientadas a servicios están cambiando la filosofía de desarrollo de software en muchos entornos. El uso de servicios web facilita significativamente la interoperabilidad entre sistemas, permitiendo programar sistemas de gran tamaño usando otros más simples de manera sencilla. El principal lenguaje para componer servicios es WS-BPEL 2.0, que ha sido estandarizado por OASIS con la participación de las grandes empresas del sector informático. Sin embargo, las principales técnicas de prueba no han sido adaptadas a WS-BPEL, quedando como uno de los principales retos para su adopción. El objetivo de esta tesis es estudiar la validez de la generación dinámica de invariantes (también conocida como generación de invariantes potenciales) para apoyar la prueba de caja blanca de composiciones de servicios web en WS-BPEL. En primer lugar, la tesis comprueba la viabilidad de la generación dinámica de invariantes para WS-BPEL. Para ello se presenta una arquitectura basada en el generador dinámico de invariantes Daikon, que ha demostrado ser útil para lenguajes imperativos como C/C++, Java y Perl. Daikon es software libre, y se ha integrado con código propio y otros dos sistemas libres: el motor de ejecución compatible WS-BPEL 2.0 ActiveBPEL y la biblioteca de prueba unitaria para WS-BPEL BPELUnit, que incorpora un mecanismo de simulación de servicios web (pues puede haber servicios no disponibles para pruebas). Los tres sistemas han sido adaptados para crear Takuan, el único generador dinámico de invariantes para WS-BPEL hasta la fecha. Tras implementar Takuan se realizaron pruebas para comprobar la utilidad de los invariantes que generaba. En ellas se observaron diversas mejoras específicas de WS-BPEL que permitirían optimizar su rendimiento. Tras implementarlas y evaluarlas, se obtuvo una mejora sustancial tanto en el tiempo de ejecución de Takuan como en la cantidad de invariantes que produce, descartando muchos invariantes no informativos y redundantes. Una vez estuvieron dichas mejoras implementadas se demostró la estabilidad de los invariantes generados por Takuan, permitiendo asegurar su correcto funcionamiento con un conjunto soporte adecuado. Los resultados obtenidos permiten afirmar la validez de la generación dinámica de invariantes para apoyar la prueba de caja blanca de composiciones WS-BPEL

Framework para la gestión de invariantes dinámicos en WS-BPEL

Este Proyecto de Fin de Carrera (PFC) ha sido realizado en colaboración con el grupo de investigación SPI&FM (Software Process Improvement and Formal Methods) en su línea de Ingeniería Web. Esta línea de investigación se encuentra centrada en el desarrollo y perfeccionamiento de tareas de prueba de software para el lenguaje WS-BPEL. En concreto, el objetivo principal es refactorizar el proceso de generación dinámico de invariantes que realiza Takuan y realizar una interfaz gráfica (denominada IdigInBPEL) para facilitar el uso del sistema

Reingeniería y ampliación del generador dinámico de invariantes potenciales para composiciones de servicios web en WS-BPEL Takuan

El lenguaje WS-BPEL, eje vertebrador del trabajo es el resultado del esfuerzo de las principales empresas TIC a nivel mundial (Microsoft, IBM, SAP, Oracle, etc.) por estandarizar la composición de servicios web. De este modo, se abre la puerta a la adopción masiva de dicho lenguaje en el mercado de las TIC en los próximos años. Como resultado, se presenta la oportunidad de investigar los elementos que permitan asegurar la calidad de dichas composiciones, siendo la generación de invariantes con Takuan una alternativa aceptada en congresos internacionales de reconocido prestigio. Este proyecto mejora y amplía el sistema

Integrating semantic business process management and viewbased modeling

Mit dem zunehmenden Interesse an Service Orientierten Architekturen und den damit verbundenen Technologien, wie zum Beispiel Web Services und der Business Process Execution Language (BPEL), hat Geschäftsprozessmanagement in den letzten Jahren an Bedeutung gewonnen. Dennoch besteht eine Kluft zwischen der Gestaltung von Geschäftsprozessen, wie sie von ExpertInnen der Geschäftswelt durchgeführt wird, und deren Ausführung, die von IT-ExpertInnen umgesetzt und gewartet wird. Derzeit gibt es intensive Forschungsansätze im Bereich semantischer Technologien, die hohe Automatisierbarkeit versprechen, sodass diese Kluft weitgehend oder sogar vollständig überwunden werden soll. Erreicht werden soll dies durch eine wohldefinierte Wissensrepräsentation, die logisches Schließen erlaubt, auf der einen Seite sowie Generation von ausführbarem Code auf der anderen Seite. In dieser Magisterarbeit analyisieren wir die Möglichkeiten, ontologisiertes Wissen in ausführbaren Code zu übersetzen und präsentieren einen allgemeinen Entwicklungsprozess, der die Möglichkeiten von Modellgetriebener Softwareentwicklung (Model Driven Software Development, MDSD) nützt, um dieses Ziel zu erreichen. Dieser allgemeine Prozess wird dann an Hand einer konkreten Implementierung im Rahmen des SemBiz Projekts evaluiert. Im Rahmen des Projektes gibt es eine Semantische Schicht, basierend auf der Web Service Modeling Ontology (WSMO), die Abfrage und Schließen über die Prozesse der Wissensbasis ermöglicht, und eine Modellgetriebene Schicht basierend auf dem Eclipse Modeling Framework (EMF), die für Prozessabstraktion und Codegenerierung verwendet wird.With the increasing interest in Service Oriented Architectures and related technologies, such as Web Services and the Business Process Execution Language (BPEL), Business Process Management (BPM) has become more and more important in recent years. However, there still exists a gap between Business Process Modeling, as it is done by business experts, and Business Process Deployment and Execution, as it is maintained by IT Experts. Currently, a lot of research is going on in the field of semantic technologies, which promise to enable a high level of automation to narrow or even close this gap. This should be achieved through a well-defined knowledge representation which allows reasoning on the one hand and generation of executable code on the other hand. In this thesis, we analyze the options to transfer ontologized knowledge representations into executable code and suggest a generic engineering process model using the facilities of Model Driven Software Development (MDSD) to fulfill this goal. This generic process is evaluated by introducing a concrete implementation done for the SemBiz project, where a semantic layer based on the Web Service Modeling Ontology (WSMO) is used for querying and reasoning over the process space, and a MDSD layer based on Eclipse Modeling Framework (EMF) is used for process abstraction and code generation

Requirements-Driven Adaptation of Choreographed Interactions

Electronic services are emerging as the de-facto enabler of interaction interoperability across organization boundaries. Cross-organizational interactions are often “choreographed”, i.e. specified by a messaging protocol from a global point of view independent of the local view of each interacting organization. Local requirements motivating an interaction as well as the global contextual requirements governing the interaction inevitably evolve over time, requiring adaptation of the corresponding interaction protocol. Adaptation of an interaction protocol must ensure the satisfaction of both sets of interaction requirements while maintaining consistency between the global view and the local views of an interaction specification. Such adaptation is not possible with the current state-of-the-art representations of choreographed interactions, as they capture only operational messaging specifications detached from both local organizational requirements as well as global contextual requirements. This thesis presents three novel contributions that tackle adaptation of choreographed interaction protocols: an automated technique for deriving an interaction protocol from requirements, a formalization of consistency between local and global views, and a framework for guiding the adaptation of a choreographed interaction. A choreographed interaction is specified using models of organizational requirements motivating the interaction. We employ the formal semantics embedded in requirements models to automatically derive an interaction protocol. We propose a framework for relating the global and local views of interaction specification and maintaining consistency between them. We develop a metamodel for interaction specification, from which we enumerate adaptation operations. We build a catalogue that provides guidance on performing each operation and propagating changes between the global and local views. These contributions are evaluated using examples from the literature as well as a real-world case study

XATA 2005: XML: aplicações e tecnologias associadas

Esta é a terceira conferência sobre a temática do XML, que tenta reunir anualmente a comunidade XML portuguesa. Olhando para o passado, e estudando o que aconteceu, podemos observar uma evolução interessante. Na primeira conferência (2003), houve uma vintena de trabalhos submetidos, maioritariamente da autoria ou da supervisão dos membros que integravam a comissão organizadora. Na segunda conferência (2004), houve uma participação mais forte da comunidade portuguesa mas ainda com números pouco expressivos. Nesta altura, apostou-se também numa forte participação da indústria, o que se traduziu num conjunto apreciável de apresentações de casos reais. Nesta terceira edição, a participação excedeu as nossas expectativas. Houve uma forte adesão nacional e internacional (Espanha e Brasil, o que para um evento onde se pretende privilegiar a língua portuguesa é ainda mais significativo). A distribuição geográfica em Portugal também aumentou, havendo mais instituições participantes. Se analisarmos as temáticas, abordadas nas três conferências, percebemos que também aqui há uma evolução no sentido de uma maior maturidade. Enquanto que no primeiro encontro, os trabalhos abordavam problemas emergentes na utilização da tecnologia, no segundo encontro a grande incidência foi nos Web Services, uma nova tecnologia baseada em XML e, no terceiro, a maior incidência é na construção de repositórios, motores de pesquisa e linguagens de interrogação. Isto poderá revelar que, de certa forma, os investigadores e os utilizadores já dominam bem a tecnologia, já têm as sua linhas de produção documental em XML e que agora é chegado o momento de armazenar aquela informação em repositórios e de a utilizar a partir deles. Se reflectirmos um pouco sobre o ciclo de vida documental, podemos concluir que o armazenamento aparece como uma das últimas fases. Por isso, podemos dizer que a comunidade portuguesa de XML "está a fechar" o ciclo de desenvolvimento documental XML. Nesta edição, houve um elevado número de submissões o que levou a uma sobrecarga de trabalho por parte dos revisores. Estes conseguiram desempenhar bem o seu papel e cumprir as datas definidas pelo "chair". Mas o que aconteceu fez-nos pensar que há necessidade de alargar ainda mais a Comissão Científica. Como consequência do número elevado de submissões houve algumas rejeições. Aos respectivos autores, fica aqui expresso um voto para que melhorem os respectivos trabalhos e de que esperamos ter contribuído para isso com os relatórios de revisão que foram enviados.Microsoft Portuga

Leveraging service-oriented business applications to a rigorous rule-centric dynamic behavioural architecture.

Today’s market competitiveness and globalisation are putting pressure on organisations to join their efforts, to focus more on cooperation and interaction and to add value to their businesses. That is, most information systems supporting these cross-organisations are characterised as service-oriented business applications, where all the emphasis is put on inter-service interactions rather than intra-service computations. Unfortunately for the development of such inter-organisational service-oriented business systems, current service technology proposes only ad-hoc, manual and static standard web-service languages such as WSDL, BPEL and WS-CDL [3, 7]. The main objective of the work reported in this thesis is thus to leverage the development of service-oriented business applications towards more reliability and dynamic adaptability, placing emphasis on the use of business rules to govern activities, while composing services. The best available software-engineering techniques for adaptability, mainly aspect-oriented mechanisms, are also to be integrated with advanced formal techniques. More specifically, the proposed approach consists of the following incremental steps. First, it models any business activity behaviour governing any service-oriented business process as Event-Condition-Action (ECA) rules. Then such informal rules are made more interaction-centric, using adapted architectural connectors. Third, still at the conceptual-level, with the aim of adapting such ECA-driven connectors, this approach borrows aspect-oriented ideas and mechanisms, and proposes to intercept events, select the properties required for interacting entities, explicitly and separately execute such ECA-driven behavioural interactions and finally dynamically weave the results into the entities involved. To ensure compliance and to preserve the implementation of this architectural conceptualisation, the work adopts the Maude language as an executable operational formalisation. For that purpose, Maude is first endowed with the notions of components and interfaces. Further, the concept of ECA-driven behavioural interactions are specified and implemented as aspects. Finally, capitalising on Maude reflection, the thesis demonstrates how to weave such interaction executions into associated services

Combining SOA and BPM Technologies for Cross-System Process Automation

This paper summarizes the results of an industry case study that introduced a cross-system business process automation solution based on a combination of SOA and BPM standard technologies (i.e., BPMN, BPEL, WSDL). Besides discussing major weaknesses of the existing, custom-built, solution and comparing them against experiences with the developed prototype, the paper presents a course of action for transforming the current solution into the proposed solution. This includes a general approach, consisting of four distinct steps, as well as specific action items that are to be performed for every step. The discussion also covers language and tool support and challenges arising from the transformation