Spring Cloud Netflix - Service Discovery Eureka Basics

Overview

This sample shows off how to use Spring Cloud Eureka for service discovery between microservices. In this sample it will be shown how message-service registers itself inside eureka, while billboard-client is able to resolve the endpoint for message-service from the eureka registry by looking it up by it's service name.

Run the Demo

• Import the root of the repo into your favorite Java IDE
• Run eureka-server application
• Run message-service application
• Browse to http://localhost:8761 and confirm that message-service is showing up in the eureka registry
• Run billboard-client application and browse it to it in your browser

Things to try out

• Examine BillboardController in billboard-client to view how the invocation URL is based on application name instead of actual endpoint. The hostname will be automatically substituted by Eureka
• Browse to eureka dashboard at http://localhost:8761. Observe that only the message-service is showing up, as billboard-client only fetches registry, but doesn't advertise itself
• Run multiple instances of message-service. Observe how a single service have multiple instance URLs in eureka dashboard. The calling application will do client-side load balancing by selecting a random instance when calling it.

Resources to Learn More:

• https://cloud.spring.io/spring-cloud-netflix/