Deployment and communication patterns in microservice architectures: A systematic literature review

Context: Microservice is an architectural style that separates large systems into small functional units to provide better modularity. A key challenge of microservice architecture design frequently discussed in the literature is the identification and decomposition of the service modules. Besides this, two other key challenges can be identified, including the deployment of the modules on the corresponding execution platform, and adopted communication patterns. Objective: This study aims to identify and describe the reported deployment approaches, and the communication platforms for microservices in the current literature. Furthermore, we aim to describe the identified obstacles of these approaches as well as the corresponding research directions. Method: A systematic literature review (SLR) is conducted using a multiphase study selection process in which we reviewed a total of 239 papers. Among these, we selected 38 of them as primary studies related to the described research questions. Results: Based on our study, we could identify three types of deployment approaches and seven different communication patterns. Moreover, we have identified eight challenges related to the deployment and six challenges related to the communication concerns. Conclusion: Our study shows that in addition to the identification of modules, the deployment and communication approaches are equally crucial for a successful application of the microservice architecture style. Various deployment approaches and communication patterns appear to be useful for different contexts. The identified research directions in the literature study show that still more research is needed to cope with the current challenges.