Service Discovery

Problem Statement

Microservice architecture structures an application as a set of loosely coupled microservices and each service can be developed independently in agile manner to enable continous delivery/deployment. These services often run in containerized/virtual environments and their number of instances and location changes dynamically.

So we require a mechanism to enable client of a microservice to make requests to dynamically changing service instances.

Solution

We can use Service Discovery pattern. To implement this pattern, we need a router/load balancer running at a particular fixed location and a service registry where all microservice instances are registered.

Now a client makes a service request, it will come to the load balancer which then inquires the service registry. If service instance is available, then the request is redirected to the available service instance.