Within a monolith application, services/code parts call each other through method calls at the implementation level. In a distributed environment, this won't be the case, since services will be running in a well-known location, and that location would be pointed out with a hostname and related port information within an HTTP-based implementation. Things will get more complicated in a Microservices-based architecture, where services can be virtualized or containerized. This would lead to an even more dynamic environment where the number of service instances and their deploy locations change frequently. To overcome this problem by addressing these insufficiencies, we will introduce the concept of service discovery. Service discovery is a mechanism that allows other execution blocks to discover information about our registered service.

We will demonstrate the Service discovery mechanisms by employing two frameworks: Snoop and Eureka. Snoop will be used for Java-EE-based Microservices, and Eureka will be used for Spring-based Microservices.