Extending an open source enterprise service bus for multi-tenancy support

Within the Cloud computing approach, Platform as a Service is a way to provide customers with the capability to deploy acquired or consumer-created applications onto the Cloud infrastructure. It relieves these of the need to install and run their own infrastructure or to manage and control the underlying Cloud infrastructure. Whereas providers of such services try to serve as many customers as possible to exploit economies of scale, especially small and medium businesses profit from this approach, because they can save the high up front and administrative cost of installing and running their own processing systems and applications. In order to offer an Enterprise Service Bus as a proven technology known from the field of Service-Oriented Architectures as a Platform in the Cloud it has to be made multi-tenant aware. This fulfills the Platform as a Service providers' need to raise the overall utilization and to maximize revenue by serving multiple customers from one system instance. This master's thesis develops a concept to extend an Enterprise Service Bus by multi-tenancy support with respect to communication and implements this concept in an open source product. The concept and implementation are evaluated by application to a scenario originating from the European project 4CaaSt

Model-Driven Development of Domain-Specific Interfaces for Complex Event Processing in Service-Oriented Architectures

Juan Boubeta-Puig has been honoured with the Extraordinary PhD Award.En la actualidad, las empresas y organizaciones de todo el planeta necesitan gestionar cada día una ingente cantidad de datos provenientes de fuentes muy diversas, tales como aplicaciones propias y de terceros, servicios web, sensores, plataformas de Internet de las cosas o redes sociales, con el fin de llevar a cabo la toma de decisiones. Un buen proceso de toma de decisiones requiere, entre otros factores, conocer tan pronto como sea posible cuál es el valor que tienen dichos datos para el negocio empresarial. La realización de un exhaustivo análisis de datos, así como una actuación temprana en relación a las situaciones críticas o relevantes que supongan una amenaza para la empresa, permitirá que esta se posicione por encima de sus competidores. No obstante, se trata de un proceso bastante complejo, debido, entre otras razones, a que gran parte de estos datos son heterogéneos - no comparten un formato común - y además deberían procesarse en tiempo real. En este contexto, el procesamiento de eventos complejos o CEP (Complex Event Processing) es una de las tecnologías software que permite analizar y correlacionar grandes volúmenes de datos en forma de eventos con el propósito de detectar situaciones de una mayor complejidad semántica, así como inferir conocimiento valioso que ayudará en el proceso de toma de decisiones. Para ello, se hace uso de los denominados patrones de eventos en los que se especifican las condiciones que han de cumplirse para detectar dichas situaciones de interés. A pesar de las grandes ventajas que CEP puede aportar en el ámbito empresarial, supone un gran reto para los usuarios que son expertos en el negocio, pero que carecen de la experiencia y los conocimientos necesarios para el uso de esta tecnología. Uno de los principales problemas a los que deben enfrentarse estos usuarios es precisamente la definición de dichos patrones usando algún lenguaje concreto, los denominados lenguajes de procesamiento de eventos o EPL (Event Processing Language). Aunque algunas soluciones software actuales ofrecen herramientas gráficas con la finalidad de solventar este problema, estas no son lo suficientemente amigables, puesto que requieren que el usuario escriba manualmente, al menos, una parte del código necesario para la definición de los patrones. Por otra parte, los sistemas de información actuales tienden a estar basados en arquitecturas orientadas a servicios o SOA (Service-Oriented Architecture), debido a que este tipo de arquitectura software permite desarrollar sistemas distribuidos altamente escalables e integrables con otros sistemas propios o de terceros. Recientemente, estas se están combinando con las arquitecturas dirigidas por eventos o EDA (Event-Driven Architecture) dando como resultado las denominadas arquitecturas orientadas a servicios y dirigidas por eventos - ED-SOA (Event-Driven Service-Oriented Architecture) o SOA 2.0, que se caracterizan porque las comunicaciones entre los usuarios, las aplicaciones y los servicios se realizan por medio de eventos de una forma totalmente desacoplada. Para detectar, en tiempo real, situaciones críticas o relevantes en estos sistemas complejos y heterogéneos, así como de ejecutar las acciones pertinentes, se hace necesaria la integración de CEP con SOA 2.0. Con el fin de dar respuesta a estas necesidades, la investigación llevada a cabo en esta tesis doctoral se ha centrado en el desarrollo dirigido por modelos de interfaces específicas de dominio para CEP en SOA 2.0, con el objeto de facilitar a los expertos en el negocio la definición tanto de los patrones que necesiten detectar en sus sistemas de información, como de las alertas que deban notificarse en tiempo real. Para lograrlo, se ha propuesto un enfoque dirigido por modelos para CEP en SOA 2.0, un lenguaje de modelado y un editor gráfico para la definición de dominios CEP, un lenguaje de modelado y un editor gráfico reconfigurable para la definición y la generación de código de patrones de eventos, así como una solución tecnológica que integra CEP con SOA 2.0. Para la evaluación del enfoque se han desarrollado dos casos de estudio que confirman que este es independiente del dominio donde se aplique. Asimismo, se concluye que los lenguajes definidos son independientes del código que implemente los patrones de eventos y las acciones a llevar a cabo, así como que los editores gráficos facilitan todo esto de una forma amigable e intuitiva, y haciendo los detalles de implementación totalmente transparentes para los expertos en el negocio. Se trata, por tanto, de un enfoque novedoso que pone la tecnología CEP al alcance de cualquier usuario, repercutiendo beneficiosamente en el proceso de toma de decisiones.Nowadays, companies and organizations all around the world need to manage huge amounts of data from heterogeneous sources - such as own and third-party applications, web services, sensors, Internet of things platforms or social networks - every day in order to conduct the decision-making process. To be successful, a decision-making process requires, among other factors, prompt information regarding what the value of such data is for the business in question. A thorough analysis of data, as well as early action for critical or relevant situations considered as threats for an organization, will allow the organization to be positioned above its competitors. Nevertheless, it is a complex process since, among other reasons, data are heterogeneous - they do not share a common format - and they should be processed in real time. In this context, Complex Event Processing (CEP) is a technology that allows the analysis and correlation of large volumes of data with the aim of detecting complex and meaningful events, and of inferring valuable knowledge for end users. This knowledge will be really helpful in the decision-making process. To do this, so-called event patterns are used. These patterns specify which conditions must be met in order to detect such situations of interest. Despite the great advantages that CEP can bring to a business, it is a substantial challenge for users who are business experts, but do not have the necessary experience and knowledge for the use of this technology. One of the main problems these users have to face is precisely the definition of these event patterns using particular languages, those called Event Processing Languages (EPLs). Although some current software solutions provide graphical tools in order to solve this problem, none of them are user-friendly enough, since they require users to hand-write at least a portion of the code for the pattern definition. On the other hand, current information systems tend to be based on Service-Oriented Architectures (SOAs) due to the fact that this type of software architecture allows the development of highly scalable distributed systems as well as their integration with own and third-party systems. Recently, these are being combined with Event-Driven Architectures (EDAs), what is known as Event-Driven Service-Oriented Architectures (ED-SOAs or SOAs 2.0). The latter enable us to establish decoupled communications between users, applications and services. The integration of CEP with SOA 2.0 is a requirement to be able to detect real-time, relevant or critical situations in these complex and heterogeneous systems, as well as for the execution of the appropriate actions. In order to respond to these needs, the research carried out in this thesis has focused on the model-driven development of domain-specific interfaces for CEP in SOAs 2.0, with the aim of facilitating the task of defining both event patterns to be detected and alerts for real time notification for domain experts. To reach this goal, the following contributions have been supplied: a model-driven approach for CEP in SOA 2.0, a modeling language and a graphical editor for CEP domain definition, a modeling language and a reconfigurable graphical editor for event pattern definition and code generation, as well as a technological solution integrating CEP with SOA 2.0. The approach has been evaluated through the development of two case studies that have confirmed independence of the approach from the application domain. Besides, we can assert that the proposed languages are independent of event patterns and actions implementation code and that user-friendly and intuitive graphical editors hide all the implementation details from end users. This is therefore a novel approach for bringing CEP technology closer to any user, positively impacting the decision making process

Offshore Wind Data Integration

Doktorgradsavhandling i informasjons- og kommunikasjonsteknologi, Universitetet i Agder, Grimstad, 2014Using renewable energy to meet the future electricity consumption and to reduce environmental impact is a significant target of many countries around the world. Wind power is one of the most promising renewable energy technologies. In particular, the development of offshore wind power is increasing rapidly due to large areas of wind resources. However, offshore wind is encountering big challenges such as effective use of wind power plants, reduced cost of installation as well as operation and maintenance (O&M). Improved O&M is likely to reduce the hazard exposure of the employees, increase income, and support offshore activities more efficiently. In order to optimize the O&M, the importance of data exchange and knowledge sharing within the offshore wind industry must be realized. With more data available and accessible, it is possible to make better decisions, and thereby improve the recovery rates and reduce the operational costs. This dissertation proposes a holistic way of improving remote operations for offshore wind farms by using data integration. Particularly, semantics and integration aspects of data integration are investigated. The research looks at both theoretical foundations and practical implementations. As the outcome of the research, a framework for data integration of offshore wind farms has been developed. The framework consists of three main components: the semantic model, the data source handling, and the information provisioning. In particular, an offshore wind ontology has been proposed to explore the semantics of wind data and enable knowledge sharing and data exchange. The ontology is aligned with semantic sensor network ontology to support management of metadata in smart grids. That is to say, the ontology-based approach has been proven to be useful in managing data and metadata in the offshore wind and in smart grids. A quality-based approach is proposed to manage, select, and provide the most suitable data source for users based upon their quality requirements and an approach to formally describing derived data in ontologies is investigated

Pristup integraciji tehničkih prostora zasnovan na preslikavanjima iinženjerstvu vođenom modelima

In order to automate development of integration adapters in industrial settings, a model-driven approach to adapter specification is devised. In this approach, a domain-specific modeling language is created to allow specification of mappings between integrated technical spaces. Also proposed is the mapping automation engine that comprises reuse and alignment algorithms. Based on mapping specifications, executable adapters are automatically generated and executed. Results of approach evaluations indicate that it is possible to use a model-driven approach to successfully integrate technical spaces and increase the automation by reusing domainspecific mappings from previously created adapters.За потребе повећања степена аутоматизације развоја адаптера за интеграцију у индустријском окружењу, осмишљен је моделом вођен приступ развоју адаптера. У оквиру овог приступа развијен је наменски језик за спецификацију пресликавања између техничких простора који су предмет интеграције. Приступ обухвата и алгоритме за поравнање и поновно искориштење претходно креираних пресликавања са циљем аутоматизације процеса спецификације. На основу креираних пресликавања, могуће je аутоматски генерисати извршиви код адаптера. У испитивањима приступа, показано је да је могуће успешно применити моделом вођен приступ у интеграцији техничких простора као и да је могуће успешно повећати степен аутоматизације поновним искоришћењем претходно креираних пресликавања.Za potrebe povećanja stepena automatizacije razvoja adaptera za integraciju u industrijskom okruženju, osmišljen je modelom vođen pristup razvoju adaptera. U okviru ovog pristupa razvijen je namenski jezik za specifikaciju preslikavanja između tehničkih prostora koji su predmet integracije. Pristup obuhvata i algoritme za poravnanje i ponovno iskorištenje prethodno kreiranih preslikavanja sa ciljem automatizacije procesa specifikacije. Na osnovu kreiranih preslikavanja, moguće je automatski generisati izvršivi kod adaptera. U ispitivanjima pristupa, pokazano je da je moguće uspešno primeniti modelom vođen pristup u integraciji tehničkih prostora kao i da je moguće uspešno povećati stepen automatizacije ponovnim iskorišćenjem prethodno kreiranih preslikavanja