For the development of cloud applications cloud providers offer independently structured services called microservices. Microservices can communicate with each other through events and connect into applications called multi-tier cloud applications.
Every cloud provider has differently defined microservices and communication between them, as standards for defining the communication and structure of microservices do not exist. That means microservices can only communicate with each other within the provider. This has led to a so-called vendor lock-in, which in some cases restricts users from developing quality cloud applications, as cloud providers offer different microservices in different qualities.
If we wanted to develop a multi-tier application from microservices of different providers, we would need an interface for communication between services, which we in this work call an event gateway. Event gateway is a technology used to receive and redirect events and enable compatibility between nodes. In the case of multi-tier applications, this means enabling communication between the micro-services of different providers.
The thesis presents a solution that enables generalized communication between multi-level services, which makes it easier for the user to develop multi-tier applications that use multiple cloud providers. The solution allows multi-tiered applications more flexibility, thanks to an expanded selection of compatible services. The purpose of the thesis is to start a conversation about solving the problem of vendor lock-in in multi-tier applications in the cloud, and about the difficult communication between multi-tier services. The field is still quite new and lacks some building blocks, such as an event gateway for multi-tier applications that could greatly contribute to the quality of applications. The desire is that the base solution would encourage cloud providers and users to develop the entire solution, which would contribute to the quality of applications developed on all cloud platforms.