Ribbon for load balancing

In the previous setup, we were always running with a single instance of the microservice. The URL is hardcoded both in client as well as in the service-to-service calls. In the real world, this is not a recommended approach, since there could be more than one service instance. If there are multiple instances, then ideally, we should use a load balancer or a local DNS server to abstract the actual instance locations, and configure an alias name or the load balancer address in the clients. The load balancer then receives the alias name, and resolves it with one of the available instances. With this approach, we can configure as many instances behind a load balancer. It also helps us to handle server failures transparent to the client.

This is achievable with Spring Cloud Netflix Ribbon. Ribbon is a client-side load balancer which can do round-robin load balancing across a set of servers. There could be other load balancing algorithms possible with the Ribbon library...