The success of Web services comes from the benefits that it brings in reducing the cost and the time needed to develop data and applications by reusing them, and simplifying their integrations through standardization. However, standardization in Web services does not remove the need for adapters due to possible heterogeneity among service interface and protocol definitions. Moreover, the current service APIs are targeted toward professional programmers, but not accessible to a wider class of users without programming expertise, but would never the less like to build their own integrated applications. In this dissertation, we propose methods and tools to support both service developers and non-expert users in their data and application integration tasks. To support service developers, we propose a framework that enables rapid development of Web service adapters. We investigate particularly the problem of service adaptation focusing on business interface and protocol layers. Our study shows that many differences between business interfaces and protocols are recurring. We introduce mismatch patterns to capture these recurring differences and provide solutions to resolve them. We present the notion of adaptation aspects, which is based on the aspect-oriented programming paradigm, to enable rapid development and deployment of service adapters. We also present a comparative study between standalone and aspect-oriented adapters development. The study shows that the aspect-oriented approach is preferable in many cases, especially when adapters need to access internal states of services. The proposed approach is implemented in a prototype tool, which is used to illustrate how it simplifies adapters development through a case study. To support users without programming expertise, we propose a spreadsheet-based Web mashups development framework, which enables users to develop mashups in the popular spreadsheet environment. First, we provide a mechanism that makes structured data first class values of spreadsheet cells. Second, we propose a new component model that can be used to develop fairly sophisticated mashups, involving joining data sources and keeping spreadsheet data up to date. Third, to simplify mashup development, we provide a collection of spreadsheet-based mashup patterns that captures common Web data access and spreadsheet presentation functionalities. Users can reuse and customize these patterns to build spreadsheet-based Web mashups instead of developing them from scratch. Fourth, we enable users to manipulate structured data presented on spreadsheet in a drag-and-drop fashion. Finally, we have developed and tested a prototype tool to demonstrate the utility of the proposed framework.

Simplifier notre interaction avec les entités informatiques interconnectées de notre environnement et faciliter l'exploitation des informations générées par celles-ci est l'objectif des environnements et applications ubiquitaires. Le comportement des applications ubiquitaires dépend de l'état et de la disponibilité des entités (logicielles ou dispositifs) qui compose l'environnement ubiquitaire dans lequel ils évoluent, ainsi que des préférences et localisation des utilisateurs. Développer et exécuter des applications ubiquitaires est un véritable défi que notre approche essaie de relever au travers de l'environnement d'exécution ApAM. Considérant que l'environnement d'exécution est imprévisible, nous partons du principe qu'une application ubiquitaire doit disposer d'une grande flexibilité dans le choix de ses composants et que cette composition doit être automatique. Nous proposons une description abstraite et implicite de la composition (où les composants et les liens entre eux ne sont pas décrits explicitement), ce qui permet de construire l'application incrémentalement pendant la phase d'exécution. La plate-forme d'exécution ApAM implémente ces mécanismes de composition incrémentale et s'en sert pour conférer aux applications ubiquitaires la capacité de « résister » et de s'adapter aux changements imprévisibles de l'environnement d'exécution. Cette propriété dite de résilience est au cœur de notre approche car elle permet aux programmeurs de développer « simplement » des applications « résilientes » sans avoir à décrire les diverses adaptations à réaliser, et même sans connaitre toutes les perturbations de l'environnement auquel elles seront soumises. Notre proposition offre le moyen de développer et d'exécuter des applications ayant un haut niveau de résilience vis-à-vis des évolutions de leur contexte d'exécution, grâce à des mécanismes automatiques capables de construire et de modifier à l'exécution l'architecture logicielle des applications ubiquitaire. Les mécanismes fournis sont génériques mais peuvent être étendus et spécialisés pour s'adapter plus finement à certaines applications ou à des domaines métiers spécifiques. / The goal of ubiquitous environments and applications is to simplify our interaction with interconnected software and hardware entities, and to allow the exploitation of the information that they gather and generate. The behavior of ubiquitous applications depends on the state and the availability of the software and hardware entities that compose the ubiquitous environment in which they are constantly evolving, as well as, the preferences and locations of users. Developing and executing ubiquitous applications is a difficult challenge that our approach attempts to address with the creation of the ApAM execution environment. Knowing that the execution environment is unpredictable, we believe that ubiquitous applications require a large amount of flexibility in choosing the components that compose the application, and that the composition should be automated. We propose an abstract and implicit description of the composition, where components and bindings are not explicitly described. This allows to incrementally building an application at runtime. The ApAM execution platform implements the mechanisms to achieve incremental composition and uses them to provide ubiquitous applications with the resilience and adaptability necessary to face unpredictable changes that originate in the execution environment. Resilience is a core property of our approach because it allows developers to easily build applications without the need to either describe nor predict the multiple adaptations required to support environmental disturbances which the applications will encounter. Our proposal offers the means of developing and executing applications with a high level of resilience in regards to their continuously evolving context. This is possible thanks to the mechanisms described in this dissertation that allow building and changing, at runtime, ubiquitous applications. These mechanisms are generic but can be extended or specialized in order to solve domain or application-specific issues.

Submitted by Daniella Sodre (daniella.sodre@ufpe.br) on 2015-03-09T12:32:57Z No. of bitstreams: 2 MSc Dissertation -Tassio Ferreira Vale.pdf: 3047313 bytes, checksum: 266f36d93884380708ea06bafe535341 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-09T12:32:57Z (GMT). No. of bitstreams: 2 MSc Dissertation -Tassio Ferreira Vale.pdf: 3047313 bytes, checksum: 266f36d93884380708ea06bafe535341 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2012-03 / A combinação de Linhas de Produto de Software (LPS) e Computação Orientada a Serviços (COS) tem recebido atenção de pesquisadores e praticantes, já que uma área é capaz de solucionar determinados problemas da outra. A junção dessas duas áreas é chamada de Linha de Produto Orientada a Serviços (LPOS), e tem se mostrado uma área de pesquisa emergente nos últimos anos. No contexto da Computação Orientada a Serviços, identificação de serviços é uma das primeiras atividades para modelagem de uma solução COS, e consiste na determinação de serviços candidatos. Essa não é uma tarefa trivial, e os erros adquiridos durante a identificação de um serviço pode propagar-se para as atividades subsequentes do processo de desenvolvimento orientado a serviços. Existem diversas propostas para identificação de serviços. Apesar da diversidade, não existe um método de identificação de serviços capaz de adequar-se a diversos contextos e necessidades. Considerando a heterogeneidade desses métodos, esta dissertação tem o objetivo de verificar quais métodos podem ser aplicados em linhas de produto de software, bem como as vantagens, desvantages e desafios existentes neste campo. Esta pesquisa utilizou uma abordagem multi-métodos, que combina estudos primários e secundários a fim de incrementar o corpo de conhecimento em determinada área baseada nos achados de tal investigação. Desta forma, este trabalho utilizou um método secundário (revisão sistemática) e dois métodos primários com o intuito de aumentar a confiabilidade dessa pesquisa. Além disso, foi realizada uma revisão da literatura a fim de coletar as abordagens de identificação de serviços existentes, visando propor uma recomendação dos métodos mais adequados considerando três cenários de LPS: top-down, bottom-up e hybrid. Esta recomendação foi avaliada através de um estudo de caso com uma linha de produto de sistemas médicos, usando dois metodos classificados no cenário o qual os sistemas médicos encontram-se, top-down. A principal contribuição dessa pesquisa é prover um instrumento que auxilie os interessados em identificar serviços a escolher um método apropriado, levando em consideração o cenário SPL a ser aplicado. Os resultados do estudo de caso mostram que as abordagens de identificação de serviços podem ser aplicadas num contexto de LPS. Além disso, este métodos facilitam a realização da atividade de identificação. / The combination of Software Product Line (SPL) and Service-Oriented Computing (SOC) have started to receive attention by researchers and practitioners, since they can address issues of each other. Putting these two areas together is called Service-Oriented Product Lines Enginering (SOPLE), presenting itself as an emerging area in the last years. In the Service-Oriented Computing, service identification is one of the first activities in the modeling of a SOC solution, that consists of determining candidate services. This is not a trivial task, and the errors made during the identification can propagate mistakes to the next activities of the service-oriented development process. There are several proposals addressing service identification for several contexts. However, an unified method for identifying services has not yet been reached. Regarding the heterogeneity of these methods, this dissertation aims to verify which methods can be applied in the SPL context, the advantages, disadvantages and the existing challenges of this field. This research used a multi-method approach that combines primary and secondary studies in order to increase the availability of empirical knowledge based on the findings of the investigation. Thus, this work used one secondary method (systematic review) and two primary methods (survey and case study) to address it. Furthermore, it was performed a literature review in order to collect all existing approaches of service identification, aiming to propose a set of decision models that recommend the most suitable methods according to three SPL scenarios: bottom-up, topdown and hybrid, onde decision model for each scenario. One of the decision models was evaluated through a case study in a medical applications domain, using two approaches classified in the decision model of the top-down scenario. The main contribution of this research is to provide an instrument that can help the service identification stakeholders to choose a suitable method, taking consideration of their SPL scenarios. In addition, these systematic methods facilitate the application of the identification activity. The case study results evaluated some service identification approaches and presented evidence that the methods can be applied in SPL.

The service oriented computing paradigm is a new model for distributed computing and due to its simplicity and powerful features, it is being popular and has a wide variety of implementation in different scenarios. The already built system is studies in detail, which was totally implemented using the Grid Technology. The idea of the current work is how we can implement the same functionality in the non-real time environment. The basic idea is to merge the web services and grid services to formulate the unique concept of context dependent quality of service (QoS) for both real time and non-real time solutions. When we merge these different types of services, the main focusing point is to define the service level agreement (SLA) when these different qualified services want to interact with each other. This document discusses and formulates the theoretical aspects, which in future work, can be consider for the practical implementation.

This Master’s Thesis examines and documents challenges related to the flexible interchange of web services within a cross-cloud Service Oriented Computing scenario (SOC).Starting with a theoretical approach, hypotheses are defined and processed to create testing scenarios for a practical examination. Both examinations are used to identify possible challenges. Next, encountered challenges are described, discussed and classified. Lastly, solution approaches to identified challenges are presented. The solution approaches concern related topics, such as service standardization, semantic methods, heuristics, and security/trust mechanisms. Several approaches to different challenges are reviewed in this particular context, to present an overview for future research on the subject.It is remarkable that there will be more service standardization in the future, but to achieve full automation it will be, on the long run, necessary to evolve and adopt more sophisticated solution approaches such as semantic methods or heuristics.This work is embedded into the framework of a research co-operation between the Linnaeus University Växjö and the University of Applied Sciences Karlsruhe. Results however are also applicable to other research scenarios.

In future service markets a selection of functionally equal services is omnipresent. The evolving challenge, finding the best-fit service, requires a distinction between the non-functional service characteristics (e.g., response time, price, availability). Service providers commonly capture those quality characteristics in so-called Service Level Agreements (SLAs). However, a service selection based on SLAs is inadequate, because the static SLAs generally do not consider the dynamic service behaviors and quality changes in a service-oriented environment. Furthermore, the profit-oriented service providers tend to embellish their SLAs by flexibly handling their correctness. Within the SOC (Service Oriented Computing) research project of the Karlsruhe University of Applied Sciences and the Linnaeus University of Sweden, a service broker framework for an optimized web service selection is introduced. Instead of relying on the providers’ quality assertions, a distributed knowledge is developed by automatically monitoring and measuring the service quality during each service consumption. The broker aims at optimizing the service selection based on the past real service performances and the defined quality preferences of a unique consumer.This thesis work concerns the design, implementation and evaluation of appropriate machine learning methods with focus on the broker’s best-fit web service selection. Within the time-critical service optimization the performance and scalability of the broker’s machine learning plays an important role. Therefore, high- performance algorithms for predicting the future non-functional service characteristics within a continuous machine learning process were implemented. The introduced so-called foreground-/background-model enables to separate the real-time request for a best-fit service selection from the time-consuming machine learning. The best-fit services for certain consumer call contexts (e.g., call location and time, quality preferences) are continuously pre-determined within the asynchronous background-model. Through this any performance issues within the critical path from the service request up to the best-fit service recommendation are eliminated. For evaluating the implemented best-fit service selection a sophisticated test data scenario with real-world characteristics was created showing services with different volatile performances, cyclic performance behaviors and performance changes in the course of time. Besides the significantly improved performance, the new implementation achieved an overall high selection accuracy. It was possible to determine in 70% of all service optimizations the actual best-fit service and in 94% of all service optimizations the actual two best-fit services.

Abstract This thesis introduces a novel Web service-centric solution to pervasive computing, called Service-oriented Pervasive Computing (also called Pervasive Service Computing), which enables computer systems to deal with context in the user’s environment, to dynamically discover and compose existing services, and to develop Internet-scale multimedia applications that support users’ activities. First, this thesis introduces the concept of Pervasive Service Computing and its relation to community coordinated multimedia, context awareness, and service-oriented computing. It then investigates the state of the art, the practices, and techniques which have been developed to support such services. Building on these tools, this study adopts a service-oriented methodology to design a reference model for Pervasive Service Computing, for accommodating specified technical requirements. This model can serve as a guide for research and development towards Pervasive Service Computing. Second, the thesis examines the nature of community coordinated multimedia, and develops the concept of Community Coordinated Multimedia (CCM). To discover the potentials of discoverability and composability of multimedia applications, the thesis introduces a model for Service-oriented Community Coordinated Multimedia (SCCM), and demonstrates the idea of “multimedia application as a service.” Furthermore, the thesis presents a content annotation service and evaluates its feasibility as an end-user prototype. Third, the thesis investigates the nature of context awareness in Pervasive Service Computing, to broaden the definition of context and context-awareness. This research introduces context-aware pervasive service composition (CAPSC) applications, and specifies three-levels of context awareness. Building on this framework, the context-aware service composition prototype is implemented. Fourth, the author examines the overall potential of service composition in Pervasive Service Computing, distinguishes its two main functions as service collaboration, and service coordination, and then develops an ODPSC (Ontology-Driven Pervasive Service Composition) ontology. To address the availability and scalability of service composition, the thesis introduces options for dynamic service composition in the Cloud, and develops an accelerated Cloud architecture for service composition in the Cloud (namely CM4SC middleware). Last, the CM4SC middleware as a service prototype is implemented. / Tiivistelmä Tässä työssä käsitellään uutta jokapaikan tietotekniikan Web-palvelukeskeistä ratkaisua, palveluorientoitunutta jokapaikan tietotekniikkaa (Pervasive Service Computing). Tämän avulla tietokonejärjestelmät voivat ottaa huomioon käyttäjän ympäristön tilanteen, löytää ja koota palveluja dynaamisesti, ja näin voidaan kehittää Internetin laajuisia käyttäjän toimintoja tukevia multimediasovelluksia. Ensiksi työssä esitellään jokapaikan tietotekniikan palvelujen käsite sekä tällaisten palveluiden suhde yhteisöllisesti koordinoituun multimediaan, tilannetietoisuuten ja palveluorientoituneeseen tietotekniikkaan. Tieteen nykytila sekä tällaisia palveluja tukemaan kehitetyt käytännöt ja tekniikat esitellään. Näihin työkaluihin pohjautuen työssä omaksutaan palveluorientoitunut metodiikka, kun jokapaikan tietotekniikan palveluille suunnitellaan referenssimalli, jonka avulla voidaan määritellä teknisiä vaatimuksia ja joka voi muutenkin toimia ohjenuorana jokapaikan tietotekniikan palvelujen tutkimukselle ja tuotekehitykselle. Toiseksi työssä tutkitaan yhteisöllisesti koordinoidun multimedian ominaispiirteitä ja määritellään yhteisöllisesti koordinoidun multimedian (Community Coordinated Multimedia, CCM) käsite. Multimediasovellusten löydettävyyden ja kokoamisen mahdollisuuksien kartoittamiseen luodaan palveluorientoitunut CCM-malli (Service-oriented Community Coordinated Multimedia, SCCM). Työssä esitellään ”multimediasovellus palveluna” -idea, jonka käyttökelpoisuutta arvioidaan sisältöpohjaisen annotoinnin prototyyppiratkaisun avulla. Kolmanneksi työssä tutkitaan jokapaikan tietotekniikan palvelujen tilannetietoisuutta laajentamalla tilanteen ja tilannetietoisuuden määritelmiä. Tutkimus esittelee tilannetietoiseen jokapaikan tietotekniikan palvelujen kokoamiseen (Context-Aware Pervasive Service Composition, CAPSC) perustuvia sovelluksia ja määrittelee kolme tasoa tilannetietoisuudelle. Tämän viitekehyksen avulla toteutetaan tilannetietoinen palvelujen kokoamisen prototyyppi. Neljänneksi työssä arvioidaan jokapaikan tietotekniikan palvelujen kokoamisen mahdollisuuksia, tunnistetaan sen kaksi keskeistä toiminnallisuutta, palvelujen yhteistoiminnallisuus (service collaboration) ja palvelujen koordinointi (service coordination), sekä kehitetään ODPSC (Ontology-Driven Pervasive Service Composition) -ontologia. Työssä esitetään saavutettavuuden ja laajennettavuuden haasteisiin ratkaisuksi dynaaminen palvelujen kokoaminen pilvipalveluna. Työssä kehitetään kiihdytetty pilviarkkitehtuuri (CM4SC-välikerrosohjelmisto) palvelujen kokoamiseen pilvessä. Lopuksi työssä toteutetaan CM4SC-välikerrosohjelmiston palveluprototyyppi.

Seleção de serviços em composições distribuídas considera principalmente a qualidade de serviço que atenda requisitos estabelecidos pelo usuário, como por exemplo, preço. No entanto, problemas relacionados a execução de composições de serviços podem ocorrer quando não se considera aspectos relacionados à rede e ao hardware, que afetam diretamente o desempenho da composição. Esse problema se agrava em composições coreografadas, pois a característica descentralizada requer um maior esforço para que essas informações possam ser consideradas em uma perspectiva global. Dessa forma, apesar da descentralização apresentar vantagens, é necessário que requisitos de qualidade de serviço da composição também sejam considerados em coreografias de serviços web para que a escolha de serviços para desempenhar um papel leve em consideração parâmetros importantes que podem afetar no desempenho da composição. Este trabalho apresenta um mecanismo, implementado sobre o framework OpenKnowledge, para selecionar serviços web em ambientes coreografados considerando primeiramente estimativas de atraso, taxa de perda e por fim considera a utilização de outros parâmetros, como utilização de CPU. Os primeiros experimentos em diferentes cenários de rede confirmaram as vantagens da proposta em relação a um seletor de serviços que ignora aspectos relacionados com a rede. Obteve-se ganhos de 20 a 97% no que diz respeito ao tempo total da execução da coreografia. Em seguida, experimentos inserindo utilização de CPU na escolha dos serviços confirmaram as vantagens de utilização de diferentes parâmetros para seleção de serviços em coreografias. / Selection of services in distributed compositions mainly considers the quality of service that meets requirements set by the user, such as price. However, problems related to the execution of service compositions may occur when aspects related to network and hardware, which directly affect the performance of the composition, are not taken in consideration. This problem is aggravated in choreographed compositions because the decentralized feature requires a greater effort so that this information may be considered in a global perspective. Thus, despite the decentralization advantages, it is necessary that the service quality requirements of the composition may also be considered in the choreography of web services so that the choice of services may play a role that takes into account important parameters, which can affect the performance of the composition. This dissertation presents a mechanism, implemented on the OpenKnowledge framework, to select web services in choreographed environments. First, considering delay estimates, loss rate and finally the use of other parameters, such as CPU utilization. The first experiments on different network scenarios confirmed the proposal advantages in relation to a selection mechanism that bypasses aspects of the network. It was obtained gains from 20% to 97% considering the total time of execution of the choreography. Then, experiments inserting CPU utilization in the choice of services confirmed the advantages of using different parameters for selection of services in choreography.

Na ultima década o paradigma de computação orientada a serviços (SOC - Service Oriented Computing) tem ganhado cada vez mais espaço na indústria e na academia, a fim de solucionar o problema da falta de comunicação entre os diversos sistemas de informação presentes dentro de um ambiente corporativo. Graças aos recentes avanços da chamada \"Web 2.0\" um novo estilo arquitetural chamado de Arquitetura orientada a Web (WOA - Web Oriented Architecture) foi proposto a fim de garantir uma maneira simples de conectar os componentes de software dinamicamente. Esse estilo tem como um dos princípios o uso de serviços Web RESTful, a fim de conseguir uma interface funcional simples e uniforme. Este trabalho apresenta um ambiente colaborativo de apoio ao desenvolvimento de serviços Web RESTful utilizando o paradigma de desenvolvimento orientado a modelos (MDD - Model Driven Development). Pretende-se mostrar os benefícios do MDD aplicado a Engenharia Web e também as vantagens apresentadas pela colaboração nesse cenário. Foi realizado ainda um experimento a fim de comprovar a eficiência do ambiente colaborativo e benefícios alcançados por ele / In the last decade the paradigm of Service Oriented Computing has gained more attention in industry and academia in order to solve the problem of lack of communication between different information systems present within a corporate environment. Due to recent advances in Web 2.0 a new architectural style called Web Oriented Architecture is proposed to ensure a simple way to connect software components dynamically. This style has as a principle the use of RESTful Web Services in order to achieve a uniform interface simple and functional. This paper presents a collaborative environment to support the development of RESTful Web Services using the Model Driven Development paradigm. It is intended to show the benefits of MDD applied to Web Engineering and also the advantages presented by collaboration in this scenario. It was also performed a experiment to prove the efficiency of the collaborative environment and benefits achieved by the same

Coreografias de serviços Web representam uma forma mais escalável e flexível de compor serviços do que uma abordagem centralizada como a orquestração, e seu papel na integração e comunicação de sistemas de larga escala é vital para os objetivos da SOC (Computação Orientada a Serviços) e da Internet do Futuro. Atualmente coreografias de serviços Web possuem vários desafios de pesquisa, dos quais a qualidade de serviço (QoS) e o monitoramento de coreografias de serviçosWeb são linhas importantes. O objetivo deste trabalho é propor e implementar um mecanismo de monitoramento não intrusivo de coreografias de serviços Web baseado em SLAs (Acordos de Nível de Serviço) que especificam as restrições de atributos de QoS de maneira probabilística. Esta dissertação propõe um mecanismo para coreografias de serviços Web que: (1) define requisitos de QoS; (2) especifica contratos probabilísticos sobre parâmetros de QoS usando SLA; e (3) realiza um monitoramento não intrusivo de coreografias de serviços Web para detectar violações de SLA. / Web services choreographies are a more scalable and flexible way to compose services than a centralized approach like orchestrations, and its role in the integration and communication of large-scale systems is vital for the goals of SoC (Service Oriented Computing) and Future Internet. Currently,Web services choreographies have several research challenges. From all challenges, quality of service (QoS) and monitoring of Web services choreography are important research lines. The goal of this work is to propose and implement a mechanism for non-intrusive monitoring of Web services choreography based on SLAs (Service Level Agreements) that define constraints of QoS attributes in a probabilistic way. This thesis proposes a mechanism for Web services choreographies that:(1) defines QoS requirements; (2) specifies probabilistic contracts on QoS parameters using SLAs; and (3) monitors, non-intrusively, the enactment of Web services choreographies to detect SLA violations.