Capturing Software Architecture Knowledge for Pattern-Driven Design

Context: Software architecture is a knowledge-intensive field. One mechanism for storing architecture knowledge is the recognition and description of architectural patterns. Selecting architectural patterns is a challenging task for software architects, as knowledge about these patterns is scattered among a wide range of literature. Method: We report on a systematic literature review, with the aim of building a decision model for the architectural pattern selection problem. Moreover, twelve experienced practitioners at software-producing organizations evaluated the usability and usefulness of the extracted knowledge.\newline Results: An overview is provided of 29 patterns and their effects on 40 quality attributes. Furthermore, we report in which systems the 29 patterns are applied and in which combinations. The practitioners confirmed that architectural knowledge supports software architects with their decision-making process to select a set of patterns for a new problem. We investigate the potential trends among architects to select patterns. Conclusion: With the knowledge available, architects can more rapidly select and eliminate combinations of patterns to design solutions. Having this knowledge readily available supports software architects in making more efficient and effective design decisions that meet their quality concerns

Identifying Requirements in Microservice Architectural Systems

Microservices and microservice architecture has grown popularity and interest steadily since 2014 but many challenges are still faced in a software project when trying to adopt the concept. This work gathers challenges, possible solutions, and requirements related to the use of microservice architecture and therefore support the work of different stakeholders in a software project using microservice architecture, while also providing more information to the research as well. The study was conducted using systematic literature review (SLR). Overall, 63 scientific publications from four different scientific databases were selected and analysed. As a result, rapid evolution, life cycle management, complexity, performance, and a large number of integrations were identified as the most common challenges of microservice architecture. Solutions such as service orchestration, fog computing, decentralized data, and use of patterns were proposed to tackle these challenges. Regarding requirements, scalability, efficiency, flexibility, loose coupling, performance, and security appeared most frequently in the literature. The key finding of this work was the importance of data. How data acts as a base for functionalities and when inaccurate can cause complex challenges and make functionalities worthless. Based on this, we have a better understanding on what challenges may occur and what to focus on while working with microservice architecture in software development

Reactive Microservices - An Experiment

Os microserviços são geralmente adotados quando a escalabilidade e flexibilidade de uma aplicação são essenciais para o seu sucesso. Apesar disto, as dependências entre serviços transmitidos através de protocolos síncronos, resultam numa única falha que pode afetar múltiplos microserviços. A adoção da capacidade de resposta numa arquitetura baseada em microserviços, através da reatividade, pode facilitar e minimizar a proliferação de erros entre serviços e na comunicação entre eles, ao dar prioridade à capacidade de resposta e à resiliência de um serviço. Esta dissertação fornece uma visão geral do estado da arte dos microserviços reativos, estruturada através de um processo de mapeamento sistemático, onde são analisados os seus atributos de qualidade mais importantes, os seus erros mais comuns, as métricas mais adequadas para a sua avaliação, e as frameworks mais relevantes. Com a informação recolhida, é apresentado o valor deste trabalho, onde a decisão do projeto e a framework a utilizar são tomadas, através da técnica de preferência de ordem por semelhança com a solução ideal e o processo de hierarquia analítica, respetivamente. Em seguida, é realizada a análise e o desenho da solução, para o respetivo projeto, onde se destacam as alterações arquiteturais necessárias para o converter num projeto de microserviços reativo. Em seguida, descreve-se a implementação da solução, começando pela configuração do projeto necessária para agilizar o processo de desenvolvimento, seguida dos principais detalhes de implementação utilizados para assegurar a reatividade e como a framework apoia e simplifica a sua implementação, finalizada pela configuração das ferramentas de métricas no projeto para apoiar os testes e a avaliação da solução. Em seguida, a validação da solução é investigada e executada com base na abordagem Goals, Questions, Metrics (GQM), para estruturar a sua análise relativamente à manutenção, escalabilidade, desempenho, testabilidade, disponibilidade, monitorabilidade e segurança, finalizada pela conclusão do trabalho global realizado, onde são listadas as contribuições, ameaças à validade e possíveis trabalhos futuros.Microservices are generally adopted when the scalability and flexibility of an application are essential to its success. Despite this, dependencies between services transmitted through synchronous protocols result in one failure, potentially affecting multiple microservices. The adoption of responsiveness in a microservices-based architecture, through reactivity, can facilitate and minimize the proliferation of errors between services and in the communication between them by prioritizing the responsiveness and resilience of a service. This dissertation provides an overview of the reactive microservices state of the art, structured through a systematic mapping process, where its most important quality attributes, pitfalls, metrics, and most relevant frameworks are analysed. With the gathered information, the value of this work is presented, where the project and framework decision are made through the technique of order preference by similarity to the ideal solution and the analytic hierarchy process, respectively. Then, the analysis and design of the solution are idealized for the respective project, where the necessary architectural changes are highlighted to convert it to a reactive microservices project. Next, the solution implementation is described, starting with the necessary project setup to speed up the development process, followed by the key implementation details employed to ensure reactivity and how the framework streamlines its implementation, finalized by the metrics tools setup in the project to support the testing and evaluation of the solution. Then, the solution validation is traced and executed based on the Goals, Questions, Metrics (GQM) approach to structure its analysis regarding maintainability, scalability, performance, testability, availability, monitorability, and security, finalized by the conclusion of the overall work done, where the contributions, threats to validity and possible future work are listed