Distributed Queries: An Evaluation of the Microservice Architecture

The microservice architecture is a new architectural style that structures an application into a set of small, independently deployable microservices, as opposed to the traditional monolith approach with a single executable. The microservice architecture is a distributed system that results in new challenges and increased complexity. This study expands the previous related research and investigates the implications of using the one-database-per-service pattern and a solution to the introduced need of queries spanning multiple microservices. In this thesis, two applications are presented, one with the microservice architecture and one monolithic counterpart, which are compared in terms of response time and throughput. As a solution for the distributed queries, the API Composition pattern was chosen. The results of the experiments conclude in a greater understanding of the difficulty in distributed queries as well as the benefits and limitations of the API composition pattern. It shows that the API composition pattern is a valid solution for distributed queries. However, it does perform worse in terms of response time and throughput than the monolith prototype. This results in the insights that one must carefully choose, with respect to the requirements of the system, when to apply it