These patterns deal with how client-side services discover locations of server-side services and are routed to them. In cloud-based applications with hundreds of microservices and instances, it is critical to abstract the physical IP address and enforce connection and security policies. Two patterns discussed here are Service Discovery and Service Routing. Service Discovery allows microservices to be discoverable without hardcoding and ensures removal of misbehaving instances. Service Routing enables routing traffic based on dynamic conditions. A more robust approach involves having a Service Discovery Service and using Client-side Load Balancing. The Service Discovery service has higher availability due to distributed storage and data sync. Implementation involves registering the IP address with a service discovery agent, looking up a service location, and sending a heartbeat to the agent for health information.
