The first solution that comes to mind is DNS. DNS maps the name with the IP address. Multiple addresses can be mapped to a single service. But, what happens when a new service spins up? We will have to add an entry in the DNS. Additionally, if we are changing the IP address of any service, the change entered in the DNS will not reflect immediately. It has to wait for TTL to reflect everywhere. DNS has the advantage of being simple and easy, and it can be used for this, but it doesn't give the flexibility for the dynamic microservice environment. Spinning up multiple copies of services is a common scenario in companies where incoming traffic is big. In this kind of environment, if any service wants to talk with a particular instance of any other service which has dynamic scaling in place, DNS will not be very helpful. As instances are coming up and down at will, maintaining their entries through a DNS will not be very instant.