Services are computational elements that expose functionality in a platform independent manner. They are the basic building blocks of the service-oriented (SO) design/integration paradigm. Composite Web Services (CWS) aggregate multiple Web Services (WSs), which is typically achieved by use of a workflow language. A workflow coordinates services in a manner that is consistent with the desired overall functionality (e.g. business process).<p> When the atomic and composite services are exposed to various users, the performance and runtime behavior of WSs becomes important. To ensure wide deployment of CWS, the performance issues must be studied. This research focuses on the performance of atomic and composite SOAP (Simple Object Access Protocol) WSs under transient overloads. This research includes conducting experiments with WSs, studying the runtime behavior, and building simulation models of WSs workflow patterns. Simulation models of different WSs workflow patterns are built to study different situations. Timeout and network latency are added to the model to better simulate real systems. The simulation models are used to predict the runtime behavior of WSs and CWS, as well as to improve the performance with existing, limited resources.

No description available.

Under sommaren 2011 utvecklade jag en iPhone applikation för tidrapportering åt Cygate AB. Denna rapport beskriver min arbetsprocess samt diskuterar och motiverar de tekniska lösningar som valts.

Services are computational elements that expose functionality in a platform independent manner. They are the basic building blocks of the service-oriented (SO) design/integration paradigm. Composite Web Services (CWS) aggregate multiple Web Services (WSs), which is typically achieved by use of a workflow language. A workflow coordinates services in a manner that is consistent with the desired overall functionality (e.g. business process).<p> When the atomic and composite services are exposed to various users, the performance and runtime behavior of WSs becomes important. To ensure wide deployment of CWS, the performance issues must be studied. This research focuses on the performance of atomic and composite SOAP (Simple Object Access Protocol) WSs under transient overloads. This research includes conducting experiments with WSs, studying the runtime behavior, and building simulation models of WSs workflow patterns. Simulation models of different WSs workflow patterns are built to study different situations. Timeout and network latency are added to the model to better simulate real systems. The simulation models are used to predict the runtime behavior of WSs and CWS, as well as to improve the performance with existing, limited resources.

Although the benefits of reusing services have been widely acknowledged, composing existing services to realize different user requirements is still a difficult and time consuming task. There have been research works on workflow templates and service design patterns that offer a higher level of reuse and assist in the composition process. Yet existing workflow templates are too specific and service design patterns may be too abstract and their effectiveness in assisting the composition process may be limited. In this dissertation, we propose a comprehensive service pattern model that is more flexible than existing workflow/service templates while allowing systematic instantiation into some concrete workflows. The service pattern supports flow control, abstract services, and prospect services (similar to a node in a design pattern). Also, we develop a set of reasoning rules to automatically verify and determine the assignment of instantiation parameters in service pattern. In addition, recent research into automated Web service composition focuses on control flow specification and enforcement. Traditionally, message mismatch between Web services appears as an orthogonal problem that can be solved using XML-based query languages. This study instead considers Web service composition and message manipulation holistically to support greater optimization of Web service composition. A proposed model, the WS-data model, focuses on data exchanges in composing Web services. Several operators with varying properties can be used to compose Web services and manipulate their input and output data. Experiments conducted on the Amazon Cloud platform show that these operators¡¦ properties can be used to develop a more efficient way for realizing a complex task, expressed according to the proposed WS-data model. It is hoped that the proposed models and automated reasoning of instantiation parameters assignment will realize the benefits of SOA in the real business settings.

Nowadays, web services have been widely utilized on the Internet. The communication of organizations becomes much easier; thanks to the advances of computer and communication technologies and the inexpensive cost, and the integration of applications within and across business organizations is a trend. In general, there are two approaches in composing web services inside or outside an organization: orchestration and choreography. Previous work in the web service selection is usually based on orchestration model and focuses on the interest of a single party. However, in many application scenarios, business goals are achieved by pair-wise interactions among a set of WSs, and there is no single entity that is in charge of selecting web service for each task. Each web service can autonomously perform web service selection. By autonomy, we maintain that each WS is aware of only its partner web services. In such a choreographic environment, we study the kind of information that each web service should provide to its partner web services and how each web service should perform web service selection so as to maximize the chance of successfully accomplish a business goal. The proposed approach is evaluated by simulating 10,000 execution sequences of the target WS and assumed a fixed operation reliability for each delegation. The experimental results show that our proposed method is close to centralized method and better than other two selection methods, namely random and view-based-propagation-free.

Business depends on the various types of information. True value comes from connecting different enterprise systems together if there is such a need.There is a way of interaction for some different software and a way of connecting software together. It is through the use of XML-based Web services.Web services enable software built on different programming languages even for different operating systems interact together. Web service is a programme on the Internet which functional possibilities can be used writing application programmes.In order to create a Web service client application it is necessary to have a proxy class in this application programme. After creating an object of the proxy class in client application programme a developer can use the Web service methods as if he used the methods of his own programmes. As a practical example which can ease accountancy records I created the Web service witch automates the process of transferring data.While improving business management systems there arose a need to create useful Web services. The usage of Web services in the business management systems is a productive and efficient job with information: its discovery, receiving, processing and saving.

Web-based Application Programming Interface (API) has become an important tool for modern software development. Many enterprises have developed various types of web APIs to support their business services, such as Google Map APIs, Twitter APIs, and eBay APIs. Due to the huge number of web APIs available in public domain, unfortunately, choosing relevant and low-risk web APIs has become an important problem for developers. This research is aimed at enhancing the recom- mendation engine for web APIs from several aspects. First, a new scanning technique is developed to detect the usage of web APIs in source codes. Using our scanning technique, we scanned over 1.7 million Open Source projects to capture the API usage patterns. Second, we integrated three machine learning models to predict compliance risks from web APIs based on their terms of services or other legal documents. Third, utilizing the knowledge learned from scanning results and compliance risks, we built a new recommendation engine for web APIs. We conducted an experimental study to evaluate our Web API recommendation engine and demonstrate its effectiveness. Some other modules, such as finding similar web APIs and searching function-related web APIs, have also been discussed. / Graduate

Made available in DSpace on 2014-06-12T16:00:27Z (GMT). No. of bitstreams: 2 arquivo6612_1.pdf: 998214 bytes, checksum: 37168127b49fe5fb921f3184b29a9612 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2007 / Web services têm desempenhado um importante papel no desenvolvimento de aplicações distribuídas. Em particular, a possibilidade de composição de serviços já implementados com o intuito de prover uma nova funcionalidade se constitui uma abordagem interessante para a construção de sistemas distribuídos e de processos de negócios (business processes), na medida em que diminui o tempo total de desenvolvimento e promove a reusabilidade de serviços já testados e utilizados. A possibilidade de realizar a composição de web services de forma dinâmica, em tempo de execução, aparece nesse contexto com uma elevada importância. A composição dinâmica permite que mudanças sejam percebidas pelo sistema durante a sua execução, sem a necessidade de reinicialização de sistemas, o que poderia levar a indisponibilidade do serviço e a possível perda de clientes. Algumas propostas têm surgido para composição dinâmica de web services, mas elas não adotam especificações já estáveis e notadamente difundidas, como WS-BPEL. Ao mesmo tempo, estas propostas usualmente implicam em modificações nas regras da especificação dos processos de negócios, dificultando ainda mais a implementação do sistema. Este trabalho propõe uma nova abordagem para possibilitar a adaptabilidade na composição de web services através de modificações na semântica da primitiva de invocação de serviços, mantendo a sintaxe do principal padrão existente para este fim (WS-BPEL) inalterada. A partir das modificações propostas, programadores podem definir composições dinâmicas de web services sem alterar o código fonte da aplicação. Como implementar a adaptação passa a ser tarefa do ambiente e não do programador, o que torna esta tarefa mais transparente para o mesmo. Por fim, a adaptabilidade surgiria como mais uma possibilidade no projeto, mantendo todas as outras características da composição inalteradas

Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-08-30T17:54:00Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_Karina_CIN.pdf: 1045991 bytes, checksum: ab1e6ae77770903f6c88d33b95b07d99 (MD5) / Made available in DSpace on 2016-08-30T17:54:00Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_Karina_CIN.pdf: 1045991 bytes, checksum: ab1e6ae77770903f6c88d33b95b07d99 (MD5) Previous issue date: 2015-07-27 / Os Web Services são componentes de software que se utilizam de tecnologias e protocolos abertos: XML, SOAP, WSDL e UDDI, para fornecer seus serviços. Atualmente, os Web Services surgem como alternativa para melhorar a comunicação entre os sistemas. Esta dissertação apresenta uma reestruturação arquitetural de Web Service - em funcionamento há quatro anos, cuja finalidade do seu serviço visa possibilitar que operações DML sejam realizadas em diferentes bases de dados de forma transparente para os usuários - fazendo uso de refatoração e padrões de projetos, garantindo que os fatores de qualidade: manutenibilidade, confiabilidade, eficiência e portabilidade, sejam mantidos. Os objetivos propostos podem ser sintetizados no entendimento e caracterização das funcionalidades e das tecnologias que envolvem os Web Services; estudos e pesquisas para descobrir quais padrões de projetos e refatoração podem ser utilizados na implementação do Web Services, possibilitando desta forma que boas práticas de desenvolvimento sejam adotadas; definir quais fatores de qualidade podem ser utilizados no processo de validação, além de, realizar avaliações e testes de Web Service fazendo uso de ferramentas Open Source; e finalmente, analisar se os resultados obtidos após o uso destes padrões na implementação do Web Service são satisfatórios. Para alcançar os objetivos propostos foi realizada uma análise da arquitetura do Web Service, por meio da engenharia reversa e análise de código. Após esta análise, refatorações e padrões de projetos foram definidos e utilizados na nova arquitetura para a implementação do novo Web Service, com o intuito de prover e garantir os fatores de qualidade: manutenibilidade, confiabilidade, eficiência e portabilidade. E por fim, testes de desempenho, carga/stress e funcional foram realizados com auxílio de ferramentas Open Source, JMeter e SoapUI, nos dois Web Services, para posteriormente seus resultados serem analisados. Os resultados obtidos, após a realização de teste e avaliação comparativa entre os dois Web Services, demonstraram uma melhora na qualidade dos serviços fornecidos pelo Web Service reestruturado, além de proporcionar redução de custo de manutenção. Assim sendo, este estudo constatou que refatoração e padrões de projetos podem ser utilizados na implementação de Web Service. / Web Services are software components that use open technologies and protocols like XML, SOAP, WSDL and UDDI, to provide its services. Currently, Web Services are an alternative to improve communication between the systems. This dissertation presents a Web Service architectural restructuring – in operation for four years, for the purpose of its service aims to enable DML operations are performed on different databases transparently to users – making use of refactoring and design patterns, ensuring that the factors of quality: maintainability, reliability, efficiency and portability are kept. The objectives proposed can be synthesized in the understanding and characterization of the features and technologies involving Web Services; study and research to find out which design patterns and refactoring can be used in the implementation of the Web Service, enabling this way that good development practices are adopted. We also identify quality factors that can be used in the validation process, as well as we carry out evaluations and testing of Web Service using Open Source tools. Finally, we analyze the results obtained after the use of these standards in the implementation of Web Service are satisfactory. To achieve the proposed was conducted an analysis of the architecture of the Web Service, by means of reverse engineering and code analysis. After this step, design patterns and refactoring have been defined and used in the new architecture for the implementation of the new Web Service, in order to provide and ensure the factors of quality: maintainability, reliability, efficiency and portability. Finally, performance testing, load/stress and functional were performed with the help of Open Source tools, JMeter and SoapUI Web Services, two for later results are analyzed. The results, after testing and benchmarking between the two Web Services, showed and improvement in the quality of services provided by the Web Service restructured, in addition to providing maintenance cost reduction. Therefore, this study found that refactorings and design patterns can be used in implementing the Web Service.