An architecture for certification-aware service discovery

Service-orientation is an emerging paradigm for building complex systems based on loosely coupled components, deployed and consumed over the network. Despite the original intent of the paradigm, its current instantiations are limited to a single trust domain (e.g., a single organization). Also, some of the key promises of service-orientation - such as the dynamic orchestration of externally provided software services, using runtime service discovery and deployment - are still unachieved. One of the main reasons for this is the trust gap that normally arises when software services, offered by previously unknown providers, are to be selected at run-time, without any human intervention. To close this gap, the concept of machine-readable security certificates (called asserts) has been recently introduced, which paves the way to automated processing about security properties of services. Similarly to current security certification schemes, the assessment of the security properties of a service is delegated to an independent third party (certification authority), who issues a corresponding assert, bound to the service. In this paper, we propose an architecture, which exploits the assert concept to realise a certification-aware service discovery framework. The architecture supports the discovery of single services based on certified security properties (in additional to the usual functional properties), as well as the dynamic synthesis of service compositions, that satisfy the given security properties. The architecture is extensible, thus allowing for a range of domain specific matchmaking components, to cover dimensions related to, e.g., performance, cost and other non-functional characteristics

Intent-based zero-touch service chaining layer for software-defined edge cloud networks

Edge Computing, along with Software Defined Networking and Network Function Virtualization, are causing network infrastructures to become as distributed clouds extended to the edge with services provided as dynamically established sequences of virtualized functions (i.e., dynamic service chains) thereby elastically addressing different processing requirements of application data flows. However, service operators and application developers are not inclined to deal with descriptive configuration directives to establish and operate services, especially in case of service chains. Intent-based Networking is emerging as a novel approach that simplifies network management and automates the implementation of network operations required by applications. This paper presents an intent-based zero-touch service chaining layer that provides the programmable provision of service chain paths in edge cloud networks. In addition to the dynamic and elastic deployment of data delivery services, the intent-based layer offers an automated adaptation of the service chains paths according to the application's goals expressed in the intent to recover from sudden congestion events in the SDN network. Experiments have been carried out in an emulated network environment to show the feasibility of the approach and to evaluate the performance of the intent layer in terms of network resource usage and adaptation overhead

Web service composition: A survey of techniques and tools

Web services are a consolidated reality of the modern Web with tremendous, increasing impact on everyday computing tasks. They turned the Web into the largest, most accepted, and most vivid distributed computing platform ever. Yet, the use and integration of Web services into composite services or applications, which is a highly sensible and conceptually non-trivial task, is still not unleashing its full magnitude of power. A consolidated analysis framework that advances the fundamental understanding of Web service composition building blocks in terms of concepts, models, languages, productivity support techniques, and tools is required. This framework is necessary to enable effective exploration, understanding, assessing, comparing, and selecting service composition models, languages, techniques, platforms, and tools. This article establishes such a framework and reviews the state of the art in service composition from an unprecedented, holistic perspective

A component-based framework for certification of components in a cloud of HPC services

HPC Shelfis a proposal of a cloud computing platform to provide component-oriented services for High Performance Computing (HPC) applications. This paper presents a Verification-as-a-Service (VaaS) framework for component certification onHPC Shelf. Certification is aimed at providing higher confidence that components of parallel computing systems ofHPC Shelfbehave as expected according to one or more requirements expressed in their contracts. To this end, new abstractions are introduced, starting with certifier components. They are designed to inspect other components and verify them for different types of functional, non-functional and behavioral requirements. The certification framework is naturally based on parallel computing techniques to speed up verification tasks.NORTE-01-0145- FEDER-000037

Jolie Microservices: An Experiment

Os microsserviços estão cada vez mais presentes no mundo das tecnologias de informação, por providenciarem uma nova forma construir sistemas mais escaláveis, ágeis e flexíveis. Apesar disto, estes trazem consigo o problema da complexidade de comunicação entre microsserviços, fazendo com que o sistema seja difícil de manter e de se perceber. Linguagens de programação específicas a microsserviços como Jolie entram em cena para tentar resolver este problema e simplificar a construção de sistemas com arquiteturas de microsserviços. Este trabalho fornece uma visão ampla do estado da arte da linguagem de programação Jolie onde é primeiramente detalhado o porquê de surgirem linguagens específicas a microsserviços e como a linguagem Jolie está construída de maneira a coincidir com as arquiteturas de microsserviços através de recursos nativos. Para demonstrar todas as vantagens de usar esta linguagem em comparação com as abordagens mais mainstream é pensado um experimento de desenvolvimento de um sistema de microsserviços no âmbito de uma aplicação de e-commerce. Este sistema é construído de forma igual usando duas bases tecnológicas – Jolie e Spring Boot. O Spring Boot é considerado a tecnologia mais usada para desenvolver sistemas de microsserviços sendo o candidato ideal para comparação. É pensada toda a análise e design deste experimento. Em seguida, a implementação da solução é detalhada a partir das configurações do sistema, escolhas arquitetónicas e como elas são implementadas. Componentes como API gateway, mediadores de mensagens, bases de dados, orquestração de microsserviços, e conteinerização para cada microsserviço e outros componentes do sistema. Pol último as soluções são comparadas e analisadas com base na abordagem Goals, Questions, Metrics (GQM). São analisadas relativamente a atributos de qualidade como manutenção, escalabilidade, desempenho e testabilidade. Após esta análise pode-se concluir que a solução construída com Jolie apresenta diferenças na manutenção sendo significativamente superior à solução baseada em Spring Boot e apresenta diferenças em termos de performance sendo ligeiramente inferior à solução construída com Spring Boot. O trabalho termina com a indicação das conquistas, dificuldades, ameaças à validade, possíveis trabalhos futuros e observações finais.Microservices are increasingly present in the world of information technologies, as they provide a new way to build more scalable, agile, and flexible systems. Despite this, they bring with them the problem of communication complexity between microservices, making the system difficult to maintain and understand. Microservices-specific programming languages like Jolie come into play to try to solve this problem and simplify the construction of systems with microservices architectures. This work provides a broad view of the State of Art of the Jolie programming language, where it is first detailed why microservices-specific languages emerge and how the Jolie language is built to match microservices architectures through native resources. To demonstrate all the advantages of using this language compared to more mainstream approaches, an experiment is designed to develop a microservices system within an e-commerce application. This system is built equally using two technological foundations – Jolie and Spring Boot. Spring Boot is considered the most used technology to develop microservices systems and is an ideal candidate for comparison. The entire analysis and design of this experiment are thought through. Then the implementation of the solution is detailed from system configurations, architectural choices, and how they are implemented. Components such as API gateway, message brokers, databases, microservices orchestration, and containerization for each microservice and other components of the system. Finally, the solutions are compared and analyzed based on the Goals, Questions, Metrics (GQM) approach. They are analyzed for quality attributes such as maintainability, scalability, performance, and testability. After this analysis, it can be concluded that the solution built with Jolie presents differences in maintenance being significant superior to the solution based on Spring Boot, and it presents differences in terms of performance being slightly inferior to the solution built with Spring Boot. The work ends with an indication of the achievements, difficulties, threats to validity, possible future work, and final observations