Communication and interaction between microservices

This diploma thesis is focused on the various types of inter-communication of microservices in terms of description, services and resiliency implementation, integration, and message systems configuration. The introductory part of this thesis identifies the key aspects of the microservices architecture and comes with both technical and business point of views. Then, follows the description of the implementation and containerization of a sample microservice, service registration and discovery, and API gateway. This thesis, thereafter, is divided into three thematic chapters based on the types of communication, i.e. synchronous, asynchronous with one and more consumers. All these chapters provide a sample use-case design based on each communication type followed by a comprehensive description of its solution and a short summary. The solution itself focuses on both technical and resiliency implementations based on the resiliency principles derived from the microservices architecture. Within these three chapters, there are messaging systems and platforms used for the communication between one or more microservices. They are briefly introduced and mutually compared. Namely, they are RabbitMQ, a representative of the AMQP protocol, and Apache Kafka, a streaming platform. The conclusion summarizes the findings of the whole thesis, the short summaries of the three key chapters, and highlights the problematic parts of the design, implementation and resiliency. Finally, possible extensions of the thesis are offered.