On the Performance and Adoption of Search-Based Microservice Identification with toMicroservices

The expensive maintenance of legacy systems leads companies to migrate such systems to microservice architectures. This migration requires the identification of system's legacy parts to become microservices. However, the successful identification of microservices, which are promising to be adoptable in practice, requires the simultaneous satisfaction of many criteria, such as coupling, cohesion, reuse and communication overhead. Search-based microservice identification has been recently investigated to address this problem. However, state-of-the-art search-based approaches are limited as they only consider one or two criteria (namely cohesion and coupling), possibly not fulfilling the practical needs of developers. To overcome these limitations, we propose toMicroservices, a many-objective search-based approach that considers five criteria, the most cited by practitioners in recent studies. Our approach was evaluated in a real-life industrial legacy system undergoing a microservice migration process. The performance of toMicroservices was quantitatively compared to a baseline. We also gathered qualitative evidence based on developers' perceptions, who judged the adoptability of the recommended microservices. The results show that our approach is both: (i) very similar to the most recent proposed approach on optimizing the traditional criteria of coupling and cohesion, but (ii) much better when taking into account all the five criteria. Finally, most of the microservice candidates were considered adoptable by practitioners.