The Problem: Service Coordination in Distributed Systems

Why was the service discovery pattern needed in the first place? Consider the problems faced in a typical microservices setup:

• Dynamic Infrastructure: In modern deployments such as virtual machines, containers and Kubernetes, services do not have fixed IP addresses or hostnames. Instances come and go, scale up and down, and get replaced during deployments. For example, an auto-scaling group in AWS launches or terminates instances based on load. Each new instance comes up with a new IP address. Keeping a written list of those addresses correct is hard.