An Empirical Study of Scalability Frameworks in Open Source Microservices-based Systems

Microservice-based systems (MBS) are distributed systems consistent of smaller components (possibly developed by separate teams using different technologies) that use lightweight mechanisms to communicate with each other. One of the main quality attributes that motivate MBS is scalability, and there are several available frameworks to face scalability challenges in MBS. However, there is still little empirical data about the architectural concerns of using these frameworks to support the scalability dimensions. This article builds upon a previous study that defined a pattern language for MBS scalability, and aims to identify and analyze which MBS frameworks are actually used in open source MBS projects to address the scalability dimensions. Results show that (1) nine common frameworks satisfy the scalability dimensions defined in the pattern language, (2) frameworks produce trade-offs among scalability dimensions, and (3) few frameworks address several scalability dimensions at once. Finally, we identify five reusable design decisions to address scalability requirements and propose them as microservices architectural tactics.