Migration of monolithic systems to microservices: A systematic mapping study

Context: The popularity of microservices architecture has grown due to its ability to address monolithic architecture issues, such as limited scalability, hard maintenance, and technological dependence. Nonetheless, the migration of monolith systems to microservices is complex. Therefore, methodologies and techniques are needed to facilitate migration and support practitioners and software architects. Objective: The objective of this study is to investigate cases of application migration, microservices identification techniques, tools used during migration, factors that promote migration, as well as issues and benefits of the migration. Method: We have conducted this SMS following the guidelines established by Kitchenham and Petersen. The research objective was defined using part of the Goal-Question-Metric model and the Population, Intervention, and Outcome criteria. From 1546 studies that were retrieved from the search execution, 114 were selected and analyzed to answer the research questions. Results: This SMS contributes with (i) a migration process proposal based on migration cases, (ii) a characterization of migration techniques based on different criteria, (iii) an analysis of tools to support migration, (iv) the identification of migration drivers, and (v) an exploration of migration issues as well as benefits. Conclusion: This SMS sheds light on the complexity and variability of migrating monolithic systems to microservices, as well as the limited number of migration tools. While scalability and maintenance drive migration, few studies assess them. Key challenges include microservices communication and database migration, with most research focusing primarily on monolith decomposition. Despite these difficulties, migration offers benefits, particularly in scalability and maintainability.