Microservices is a popular architectural approach for complex systems in companies, despite its nature of decentralization. There is a comprehensive set of microservices architectural patterns that guides implementations and helps developers to overcome issues. However, the community still scarcely adopts these patterns and only has a theoretical understanding of them. In this work, in order to increase awareness of such patterns and provide aid to developers to better understand an architecture based on microservices, we propose a detection approach based on metrics for microservices patterns. We focused on structural or architectural patterns, and implemented detection for five of them. We conducted two case studies with real-world applications and evaluated the accuracy and applicability of our approach with the developers of those applications.

Microservices Architecture is a trending solution for large systems, which counts with an extensive pattern language that defines its base practices and documents solutions to recurrent problems. However, there is a lack of studies investigating how these patterns are known and applied by professionals. Understanding how the patterns are used enables to comprehend the design process for this architectural style and identify opportunities for improvement. So, this work aims to collect and analyze information about how professionals know and use microservice patterns. To achieve that, we conducted a questionnaire study focused on eleven patterns that directly influence the architecture and components structure. The questionnaire was answered by 63 participants and revealed that, in general, they know the patterns, but with a significant amount declaring that it was known only as a practice. Additionally, among other results, our study also identified that the patterns are more commonly adopted at the project beginning rather than by refactoring and that they frequently are adopted more than once in the same system.