Abstract-The accelerating progress of network speed, reliability and security creates an increasing demand to move software and services from being stored and processed locally on users' machines to being managed by third parties that are accessible through the network. This has created the need to develop new software development methods and software architectural styles that meet these new demands. One such example in software architectural design is the recent emergence of the microservices architecture to address the maintenance and scalability demands of online service providers. As microservice architecture is a new research area, the need for a systematic mapping study is crucial in order to summarise the progress so far and identify the gaps and requirements for future studies. In this paper we present a systematic mapping study of microservices architectures and their implementation. Our study focuses on identifying architectural challenges, the architectural diagrams/views and quality attributes related to microsevice systems.

Micro service architectures are rapidly establishing themselves in the software industry as a more efficient and effective substitute for monolithic applications. In a micro service architecture, the application is broken down into many small elements called micro services. These are managed in a distributed way and typically involve several development teams. In such an environment, an architectural model can get lost along the way, making it difficult to perform many downstream software engineering tasks, such as migration, audit, integration or impact analysis. To address this problem, we are developing support for Micro Service Architecture Recovery (MiSAR) using a Model Driven Engineering approach. In this paper, we describe an empirical study which aims to identify the core elements of our approach, by undertaking manual analysis on 8 micro service-based open source projects. From this analysis, we define a metamodel for micro service-based architectures and a set of mapping rules which map between the software and the metamodel. The resulting metamodel and mapping rules provide a solid foundation for any micro service architecture recovery approach and hence are a key first step towards managing the architectural integrity of micro servicebased applications.

<p>Microservice architecture is considered a dominant architectural style in current software systems. It views a software system as a collection of small and independent services called microservices. In the highly dynamic enterprise domain, new features have to be introduced regularly and the microservice architectural style achieves quick time-to-market. However, software engineers (e.g., developers or architects) often face the challenge of not having a holistic software architectural view of the system they are working with. This is specifically emphasized in the nature of the microservice architecture, as microservices are small, distributed and the dependencies and interactions between them are high. In our previous work, we demonstrated the requirements for building a Model Driven Architecture (MDA) approach called Microservice Architecture Recovery (MiSAR). This paper starts by reporting on an empirical study conducted on nine microservice systems with the aim of defining the MDA artefacts to semi-automatically recover architectural models of microservice systems. The study resulted in defining a set of: 1) requirements to be present in a metamodel for recovering microservice architecture, which we have implemented incrementally to obtain a MiSAR metamodel and 2) mapping rules to transform the Platform Specific Model to a Platform Independent one. Then, the Model-Driven artefacts (metamodels and transformations) are implemented to support the semi-automatic recovery of microservice architecture. Finally, we evaluated MiSAR in 3 case studies by semi-automatically recovering the architectural models of 3 systems and compared the recovered architectural models with their actual implemented architectures and with their documented ones. We demonstrate that MiSAR artefacts can produce effective and expressive architectural models of implemented microservice systems.</p>

<p>Microservice architecture is considered a dominant architectural style in current software systems. It views a software system as a collection of small and independent services called microservices. In the highly dynamic enterprise domain, new features have to be introduced regularly and the microservice architectural style achieves quick time-to-market. However, software engineers (e.g., developers or architects) often face the challenge of not having a holistic software architectural view of the system they are working with. This is specifically emphasized in the nature of the microservice architecture, as microservices are small, distributed and the dependencies and interactions between them are high. In our previous work, we demonstrated the requirements for building a Model Driven Architecture (MDA) approach called Microservice Architecture Recovery (MiSAR). This paper starts by reporting on an empirical study conducted on nine microservice systems with the aim of defining the MDA artefacts to semi-automatically recover architectural models of microservice systems. The study resulted in defining a set of: 1) requirements to be present in a metamodel for recovering microservice architecture, which we have implemented incrementally to obtain a MiSAR metamodel and 2) mapping rules to transform the Platform Specific Model to a Platform Independent one. Then, the Model-Driven artefacts (metamodels and transformations) are implemented to support the semi-automatic recovery of microservice architecture. Finally, we evaluated MiSAR in 3 case studies by semi-automatically recovering the architectural models of 3 systems and compared the recovered architectural models with their actual implemented architectures and with their documented ones. We demonstrate that MiSAR artefacts can produce effective and expressive architectural models of implemented microservice systems.</p>