Accurate situational assessment is key to any decision maker and especially crucial in military command and control, air traffic control, and complex system decision making. Endsley described three dependent levels of situational awareness, (1) perception, (2) understanding, and (3) projection. This research was focused on Endsley's second-level situational awareness (understanding) as it applies to service-oriented information technology environments in the context of the Semantic Web. Specifically, this research addressed the problem of developing accurate situational assessments related to the status or health of information technology (IT) services, especially composite, dynamic IT services, when some of Endsley's first level (perceived) information was inaccurate or incomplete. Research had not adequately addressed the problem of how to work with inaccuracy and situational awareness information in order to produce accurate situational assessments for Semantic Web services. This problem becomes especially important as the current Web moves towards a Semantic Web where information technology is expected to be represented and processed by machines. Costa's probabilistic Web ontology language (PR-OWL), as extended by Carvalho (PR-OWL2), is a framework for storage of and reasoning with uncertainty information as part of the Semantic Web. This study used Costa's PR-OWL framework, as extended by Carvalho, to build an ontology that supports reasoning with service-oriented information in the context of the Semantic Web and then assessed the effectiveness of the developed ontology through the use of competency questions, as described by Gruninger and Fox and verified through the use of an automated reasoner. This research resulted in a Web Ontology Language for Services (OWL-S), PR-OWL2 based ontology, and its associated Multi-Entity Bayesian Network which are flexible and highly effective in calculating situational assessments through the propagation of posterior probabilities using Bayesian logic. Specifically, this research (1) identifies sufficient information required for effective situational awareness reasoning, (2) specifies the predicates and semantics necessary to represent service components and dependencies, (3) applies Multi-Entity Bayesian Network to reason with situational awareness information, (4) ensures the correctness and consistency of the situational awareness ontology, and (5) accurately estimates posterior probabilities consistent with situational awareness information.

Com a tendência de aumento do uso de tecnologias móveis conectadas à web, é comum que empresas (provedores) provejam seus serviços na web para que possam atender requisições de usuários em diversas situações. Muitas vezes é necessário que serviços de dois ou mais provedores sejam compostos automaticamente para que uma única requisição de usuário seja atendida no momento imediatamente anterior à execução do serviço: é a composição automática de serviços. Quando uma composição de serviços é executada, ela está automatizando um processo de negócio relativo à requisição do usuário. O objetivo dessa pesquisa é contribuir com um modelo arquitetural de sistema básico de composição automática de serviços baseado em semântica. Este modelo contempla a utilização de similaridade entre conceitos de uma ontologia de um domínio específico, desta maneira possibilitando que uma mesma requisição de um usuário possa ser atendida de diversas maneiras distintas e com serviços heterogêneos. A proposta é validada através de um protótipo em software e a experimentação é aplicada no domínio do turismo. / With the trend towards increased use of mobile technologies over the web, companies (providers) have been increasingly providing their services on the web to fulfill user requests in various situations. It is often necessary that two or more services from different providers are automatically composed in order to meet a single user request at the moment immediately previous to the service execution: this is called automatic composition of services. The objective of this research is to contribute with a semantics based automatic composition model that uses similarity between concepts of an ontology to generate alternative business processes, thus enabling a single user request to be met in several different ways using heterogeneous services. The proposal is validated through a software prototype and the experimentation is applied in the tourism domain.

Short time-to-bug localization is extremely important for any 24x7 service-oriented application. To this end, we introduce a new debugging paradigm called live debugging. There are two goals that any live debugging infrastructure must meet: Firstly, it must offer real-time insight for bug diagnosis and localization, which is paramount when errors happen in user-facing applications. Secondly, live debugging should not impact user-facing performance for normal events. In large distributed applications, bugs which impact only a small percentage of users are common. In such scenarios, debugging a small part of the application should not impact the entire system. With the above-stated goals in mind, this thesis presents a framework called Parikshan, which leverages user-space containers (OpenVZ) to launch application instances for the express purpose of live debugging. Parikshan is driven by a live-cloning process, which generates a replica (called debug container) of production services, cloned from a production container which continues to provide the real output to the user. The debug container provides a sandbox environment, for safe execution of monitoring/debugging done by the users without any perturbation to the execution environment. As a part of this framework, we have designed customized-network proxies, which replicate inputs from clients to both the production and test-container, as well safely discard all outputs. Together the network duplicator, and the debug container ensure both compute and network isolation of the debugging environment. We believe that this piece of work provides the first of its kind practical real-time debugging of large multi-tier and cloud applications, without requiring any application downtime, and minimal performance impact.

Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2018-04-24T12:51:11Z No. of bitstreams: 1 texto completo.pdf: 4535588 bytes, checksum: e1e2595e7892830d7251e26dfe36c58d (MD5) / Approved for entry into archive by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2018-04-24T12:52:10Z (GMT) No. of bitstreams: 1 texto completo.pdf: 4535588 bytes, checksum: e1e2595e7892830d7251e26dfe36c58d (MD5) / Approved for entry into archive by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2018-04-24T12:52:28Z (GMT) No. of bitstreams: 1 texto completo.pdf: 4535588 bytes, checksum: e1e2595e7892830d7251e26dfe36c58d (MD5) / Made available in DSpace on 2018-04-24T12:52:48Z (GMT). No. of bitstreams: 1 texto completo.pdf: 4535588 bytes, checksum: e1e2595e7892830d7251e26dfe36c58d (MD5) Previous issue date: 2018-01 / Albeit several IoT applications have been recently deployed in several fields, including environment and industry monitoring, Smart Home, Smart Hospital and Smart Agriculture, current deployments are mostly host-oriented, which is undoubtedly limiting the attained benefits brought up by IoT. Indeed, future IoT applications shall benefit from service - oriented communications, where the communication establishment between end-points is not dependent on prior knowledge of the host devices in charge of providing the service execution. Rather, an end-user service execution request is mapped into the most suitable resources able to provide the requested service. Furthermore, this model is a key enabler for the design of future services in Smart Cities, e-Health, Intelligent Transportation Systems, among other smart scenarios. Recognized the benefits of this model in future applications, considerable research effort must be devoted for addressing several challenges yet unsolved, such as the ones brought up by the high dynamicity and heterogeneity inherent to these scenarios. In fact, service-oriented communication requires an updated view of available resources, mapping service requests into the most suitable resources taking several constraints and requirements into account, resilience provisioning, QoS-aware service allocation, just to name a few. This thesis aims at proposing and evaluating mechanisms for efficient resource allocation in service-oriented IoT scenarios through the employment of two distinct baseline technologies. In the first approach, the so-called Path Computation Element (PCE), designed to decouple the host-oriented routing function from GMPLS switches in a centralized element, is extended to the service-oriented PCE (S-PCE) architecture, where a service identifier (SID) is used to identify the service required by an end-user. In this approach, the service request is mapped to one or a set of resources by a 2-steps mapping scheme that enables both selection of suitable resources according to request and resources characteristics, and avoidance of service disruption due to possible changes on resources’ location. In the meantime, the inception of fog computing, as an extension of the cloud computing concept, leveraging idle computing resources at the edge of the network through their organization as highly virtualized micro data centers (MDC) enabled the reduction on the network latency observed by services launched at edge devices, further reducing the traffic at the core network and the energy consumption by network and cloud data center equipment, besides other benefits. Envisioning the benefits of the distributed and coordinated employment of both fog and cloud resources, the Fog-to-Cloud (F2C) architecture has been recently proposed, further empowering the distributed allocation of services into the most suitable resources, be it in cloud, fog or both. Since future IoT applications shall present strict demands that may be satisfied through a combined fog-cloud solution, aligned to the F2C architecture, the second approach for the service-oriented resource allocation, considered in this thesis, aims at providing QoS -aware resource allocation through the deployment of a hierarchical F2C topology, where resource are logically distributed into layers providing distinct characteristics in terms of network latency, disruption probability, IT power, etc. Therefore, distinct strategies for service distribution in F2C architectures, taking into consideration features such as service transmission delay, energy consumption and network load. Concerning the need for failure recovery mechanisms, distinct demands of heterogeneous services are considered in order to assess distinct strategies for allocation of protection resources in the F2C hierarchy. In addition, the impact of the layered control topology on the efficient allocation of resources in F2C is further evaluated. Finally, avenues for future work are presented. / Lattes não encontrado, autor sem cpf, agência de fomento e ficha catalográfica

Com a tendência de aumento do uso de tecnologias móveis conectadas à web, é comum que empresas (provedores) provejam seus serviços na web para que possam atender requisições de usuários em diversas situações. Muitas vezes é necessário que serviços de dois ou mais provedores sejam compostos automaticamente para que uma única requisição de usuário seja atendida no momento imediatamente anterior à execução do serviço: é a composição automática de serviços. Quando uma composição de serviços é executada, ela está automatizando um processo de negócio relativo à requisição do usuário. O objetivo dessa pesquisa é contribuir com um modelo arquitetural de sistema básico de composição automática de serviços baseado em semântica. Este modelo contempla a utilização de similaridade entre conceitos de uma ontologia de um domínio específico, desta maneira possibilitando que uma mesma requisição de um usuário possa ser atendida de diversas maneiras distintas e com serviços heterogêneos. A proposta é validada através de um protótipo em software e a experimentação é aplicada no domínio do turismo. / With the trend towards increased use of mobile technologies over the web, companies (providers) have been increasingly providing their services on the web to fulfill user requests in various situations. It is often necessary that two or more services from different providers are automatically composed in order to meet a single user request at the moment immediately previous to the service execution: this is called automatic composition of services. The objective of this research is to contribute with a semantics based automatic composition model that uses similarity between concepts of an ontology to generate alternative business processes, thus enabling a single user request to be met in several different ways using heterogeneous services. The proposal is validated through a software prototype and the experimentation is applied in the tourism domain.

As the pace of business change increases, service-oriented (SO) solutions should facilitate easier maintainability as underlying business logic and rules change. To date, little effort has been dedicated to considering how the structural properties of coupling and cohesion may impact on the maintainability of SO software products. Moreover, due to the unique design characteristics of Service-Oriented Computing (SOC), existing Procedural and Object-Oriented (OO) software metrics are not sufficient for the accurate measurement of service-oriented design structures. This thesis makes a contribution to the field of SOC, and Software Engineering in general, by proposing and evaluating a suite of design-level coupling and cohesion metrics for predicting the maintainability of service-oriented software products early in the Software Development LifeCycle (SDLC). The proposed metrics can provide the following benefits: i) facilitate design decisions that could lead to the specification of quality SO designs that can be maintained more easily; ii) identify design problems that can potentially have a negative effect on the maintainability of existing service-oriented design structures; and iii) support more effective control of maintainability in the earlier stages of SDLC. More specifically, the following research was conducted as part of this thesis: - A formal mathematical model covering the structural and behavioural properties of service-oriented system design was specified. - Software metrics were defined in a precise, unambiguous, and formal manner using the above model. - The metrics were theoretically validated and empirically evaluated in order to determine the success of this thesis as follows: a. Theoretical validation was based on the property-based software engineering measurement framework. All the proposed metrics were deemed as theoretically valid. b. Empirical evaluation employed a controlled experimental study involving ten participants who performed a range of maintenance tasks on two SO systems developed (and measured using the proposed metrics) specifically for this study. The majority of the experimental outcomes compared favourably with our expectations and hypotheses. More specifically, the results indicated that most of the proposed metrics can be used to predict the maintainability of service-oriented software products early in the SDLC, thereby providing evidence for the validity and potential usefulness of the derived metrics. Nevertheless, a broader range of industrial scale experiments and analyses are required to fully demonstrate the practical applicability of the metrics. This has been left to future work.

In today’s volatile business environments, collaboration between information systems, both within and across company borders, has become essential to success. An efficient supply chain, for example, requires the collaboration of distributed and heterogeneous systems of multiple companies. Developing such collaborative applications and building the supporting information systems poses several engineering challenges. A key challenge is to manage the ever growing design complexity. In this article, we argue that software architecture should play a more prominent role in the development of collaborative applications. This can help to better manage design complexity by modularizing collaborations and separating concerns. State of the art solutions, however, often lack proper abstractions for modeling collaborations at architectural level or do not reify these abstractions at detailed design and implementation level. Developers, on the other hand, rely on middleware, business process management, and Web services, techniques that mainly focus on low-level infrastructure. To address the problem of managing the design complexity of collaborative applications, we present Macodo. Macodo consists of three complementary parts: (1) a set of abstractions for modeling adaptive collaborations, (2) a set of architectural views, the main contribution of this article, that reify these abstractions at architectural level, and (3) a proof of concept middleware infrastructure that supports the architectural abstractions at design and implementation level. We evaluate the architectural views in a controlled experiment. Results show that the use of Macodo can reduce fault density and design complexity, and improve reuse and productivity. The main contributions of this article are illustrated in a supply chain management case.

Service-oriented architecture (SOA) approach has become the mainstream of today¡¦s systems development technique. The Unified Modeling Language (UML) is becoming the major tool for modeling the platform independent model (PIM) of a SOA system. Once the PIM is constructed, the results can then be transformed into its platform specific model based on the model driven architecture (MDA) approach and a specific platform. To develop a SOA system, the developer can then use the platform and choose the proper components to construct services and then business processes. However, the detailed guideline for this type of construction based on a specific platform is lacking. Therefore, this study presents a methodology which provides guidelines for the construction from components, service to business process for a SOA system based on the IBM WebSphere platform. The research methodology is articulated using the design science research methodology. A usability evaluation with a hypothesized case is performed to demonstrate its applicability. The results indicated that with this proposed method, the system developer can effectively use the IBM WebSphere platform to construct the business process based on the PIM of a SOA system.

At this stage, enterprises are faced with rapidly changing business environment. With estimated the relative reaction time and decision-making has also become very short time. Any decision-making will be on corporate organizational structure and business process changes consequent. The adjustments of the enterprises would require the co-ordination of Information Systems. How to quickly modify the information system for the enterprises has become a very important issue. This thesis has a website for example that describes how to use the Service-Oriented Architects Association Website Model (SOAAWM) of the amendment to the enterprise information system. SOAAWM uses four tools such as architecture hierarchy diagram, service operation diagram, structure-behavior coalescence diagram, and business process diagram to build up the website. SOAAWM is based on the service-oriented theory and method. By using the structure-behavior coalescence approach embedded in SOAAWM, we are able to describe working situations of organizational structures, business processes, and information systems clearly enough to reduce the business risks. In this study, through structure-behavior coalescence approach embedded in the theory and method of service-oriented re-planning of the organizational structures and business processes, making such a great level of complexity and impact of information systems can be avoided in the build omissions or bias, but also enhance the post on-line information system communication efficiency and maintain quality. This is the major achievement of our research.

<p>Detta examensarbete behandlar Service Oriented Architecture (SOA) och dess implementeringar Jini och Web services. SOA beskriver hur applikationsintegration mellan olika plattformar skall ske och innebär att applikationer designas som tjänster för att enkelt integreras med andra applikationer. Dynamisk lokalisering av tjänster via en registertjänst används för att applikationer skall finna andra applikationer. Vi designar och implementerar en mekanism i Web services som gör det möjligt att byta en tjänst under exekvering. Ett sådant byte kan vara intressant av två skäl, tjänster kan registreras utan att vara tillgängliga, eller att det uppstår ett fel under exekvering som gör att tjänsten blir otillgänglig.</p> / <p>This degree project is about Service Oriented Architecture (SOA) and its implementations Jini and Web services. SOA is a description of how application integration between different platforms can be carried out by designing applications as services, which implies an easier integration with other applications. Dynamic location of services is carried out by consultation with a register service so that applications can find other applications. We design and implement a mechanism in Web services that makes it possible to change service during execution. A change of service can be interesting for two reasons, the service might be registered but not available or there might be some sort of fault during execution that makes the service unavailable.</p>