Spring Cloud Netflix Sample

This project is intended to be a test and practical example of several spring cloud technologies, namely:

• Service discovery via Eureka server or Consul Server
• Client side balancing using Ribbon
• Edge server using zuul
• Circuit breaker using Hystrix
• Real time monitoring using Hystrix Dashboard + Turbine
• Log correlation using sleuth

We also use other interesting technologies

• Swagger to document microservices API
• Examples on how to serialize and document new java.time classes

There are two maven profiles defined to choose between consul and Eureka. Eureka profile is active by default.

Service discovery via Eureka server

Build project using:

mvn clean package

Service discovery via Consul server

Build project using:

mvn clean package -P -discoveryServiceEureka,discoveryServiceConsul

The run script presupposes that you have consul installed and runs a local development instance.

It uses tags to select instances to be called (i.e. mirroring AWS availability zones).

Client side balancing using Ribbon

Edge server using zuul

Exposed endpoints: http://localhost:8080/microserviceOne/testCallOne http://localhost:8080/microserviceTwo/testCallTwo

Circuit breaker using Hystrix

Real time monitoring

Real time monitoring using Hystrix Dashboard + Turbine to aggregate all monitoring streams in a single Dashboard.

Turbine works with consul but still lacks metadata functionality to specify customs CLUSTER keys

Log correlation using sleuth

Adding spring.cloud.sleuth dependency we get a consistent TraceId added to all the logs in all microservices, and we also get the following header in the JSon response: X-B3-TraceId: c058d819e6499487

Using swagger to document microservices API

Online documentation and tester available at: http://localhost:xxxx/swagger-ui.html JSON swagger API specification available at: http://localhost:xxxx/api-docs/

How to run test sample

Use run-test-suit-[eureka|consul].sh to start the test (in a local machine environment). The script uses cygwin, although it shouldn't be difficult to change to a linux environment.

Interesting Links

• http://cloud.spring.io/spring-cloud-netflix/spring-cloud-netflix.html
• https://github.com/ewolff/microservice A similar demo (using docker)

Hystrix

• https://github.com/Netflix/Hystrix/wiki/How-To-Use#common-patterns
• http://projects.spring.io/spring-cloud/spring-cloud.html#_hystrix_metrics_stream

Turbine

• https://github.com/Netflix/Turbine/wiki/Configuration-(1.x)#provided-implementations-for-instancediscovery
• https://github.com/Netflix/Turbine/wiki/Configuration-(1.x)#important-note

Swagger and SpringFox

• http://springfox.github.io/springfox/docs/current/
• https://github.com/swagger-api/swagger-core/wiki/Annotations-1.5.X
• http://www.hascode.com/2015/07/integrating-swagger-into-a-spring-boot-restful-webservice-with-springfox/
• http://heidloff.net/article/usage-of-swagger-2-0-in-spring-boot-applications-to-document-apis/
• http://fizzylogic.nl/2015/07/29/quickly-generate-api-docs-for-your-spring-boot-application-using-springfox/