snicoll-scratches/rest-microservices

Sample for Spring Boot based REST microservices

REST based micro-services sample

tl;dr

• Two Spring Boot based Maven projects that are standalone applications:
  • Stores (MongoDB, exposing a few Starbucks shops across north america, geo-spatial functionality)
  • Customers (JPA)

Fundamentals

The core domain and focus of the example can be explored by simply starting both the customer and the store service using mvn spring-boot:run. The store service exposes a resource to trigger geo-spatial queries for Starbucks shops given a reference location and distance.

The customer service

TODO

The use of Hystrix

The customer service uses Hystrix to short-circuit the discovery calls trying to find the store system if the link discovery or validation fails repeatedly. To see this working run the hystrix-dashboard app (mvn spring-boot:run), browse to http://localhost:7979/hystrix and point the dashboard to the ustomer service's Hystrix stream (http://localhost:8080/hystrix.stream).

Using service discovery

As an alternative to the static service reference the customer service uses by default, service discovery via Eureka can be used. Make sure both the customer and store service are stopped. Start the eureka-server application using mvn spring-boot:run. Browse http://localhost:8761 to see the Eureka web interface.

Now start both the customer and the store service with the cloud profile enabled (mvn spring-boot:run -Dspring.profiles.active="cloud"). Inspecting the Eureka web interface you should see both instances being registered with the registry. The customer service now uses a DiscoveryClient to obtain a ServiceInstance by name (see the CustomerApplication.CloudConfig.dynamicServiceProvider(…) bean definition).