This document discusses how Netflix OSS and Spring Cloud can be used together to implement a microservices architecture. It describes various libraries like Eureka for service discovery, Hystrix for circuit breaking, Ribbon for load balancing, and Zuul for API gateway functionality. It also explains how Spring Boot simplifies application development and Spring Cloud integrates these Netflix libraries and provides additional features like a configuration server. Overall, Netflix OSS and Spring Cloud provide the tools needed to build resilient microservices with service discovery, load balancing, and other capabilities in a transparent way for developers.

1. Microservices with
Netflix OSS & Spring Cloud
Arnaud Cogoluègnes
Lyon, October 6th, 2015

2. Microservices with
Netflix OSS & Spring Cloud
Arnaud Cogoluègnes
Spring Framework
Spring Boot
Spring Cloud
Eureka, Hystrix, Zuul, Ribbon
Service discoveryCircuit breaker
Load balancing
API gateway
Configuration
server

3. Speaker: Arnaud Cogoluègnes

4. Netflix OSS and Spring Cloud aren’t
limited to the cloud
infrastructure or container solutions

5. Netflix OSS and Spring Cloud are
application frameworks
also valid for traditional applications
open source

6. Docker Container Docker Container
Where does it fit?
Spring Boot Application
(Netflix OSS & Spring Cloud)
Java Virtual Machine
Eureka Service Registry
Java Virtual Machine
Infrastructure
(Mesos, vanilla datacenter, VM, Cloud Foundry, AWS, laptop)

7. The use case
Frontend
Backend
(instance 1)
Backend
(instance 2)
Service registry
(Eureka)
Discovers
Registers
Registers
Balances

8. Wishlist
Packaging
Security
Service discovery
Monitoring
Continuous deployment
Resiliency
Centralized logging
Centralized
configuration

9. Netflix stack
Eureka (service registry)
Hystrix (circuit breaker)
Ribbon (client load balancer)
Zuul (proxy)
....

10. Spring Cloud
Built on top of Spring Boot
Spring-ifies some nifty libraries (e.g. Netflix)
Provides goodies (e.g. configuration server)
Pretty much all you need for microservices

11. Spring Boot
Spring Framework for the masses
No XML, no container (as you wish)
All the Spring stuff:
Dependency injection, transaction
management, REST, ...

12. Eureka server with Spring Boot
@SpringBootApplication
@EnableEurekaServer // activates Eureka
public class EurekaServer {
public static void main(String[] args) {
SpringApplication.run(EurekaServer.class, args);
}
}

13. Eureka server
Frontend
Backend
(instance 1)
Backend
(instance 2)
Service registry
(Eureka)

14. Eureka client with Spring Cloud
@SpringBootApplication
@EnableEurekaClient // application registers to Eureka
public class BackendServiceApplication {
public static void main(String[] args) {
SpringApplication.run(BackendServiceApplication.class, args);
}
}

15. Eureka client
Frontend
Backend
(instance 1)
Backend
(instance 2)
Service registry
(Eureka)
Discovers
Registers
Registers

16. REST client call
@Repository
public class ContactRepository {
@Autowired RestTemplate restClient;
public ContactsResponse contacts() {
ContactsResponse response = restClient.getForObject(
"http://backend-service/contacts", // host = service name
ContactsResponse. class
);
response.setOk( true);
return response;
}

17. Client load balancer: Ribbon
Handles HTTP requests
Balances load and detects failures
Resolves services from Eureka

18. Client load balancing
Frontend
Backend
(instance 1)
Backend
(instance 2)
Service registry
(Eureka)
Balances

19. Circuit breaker: Hystrix
Why? To prevent cascading failure
How? async, detect failures, open/close
Where? Around services calls

20. Hystrix with Spring Cloud
@Repository
public class ContactRepository {
@HystrixCommand(fallbackMethod = "contactsFailure")
public ContactsResponse contacts() {
// real call (protected by circuit breaker)
}
public ContactsResponse contactsFailure() {
// fallback, when real call fails
}
}

21. Circuit breaker
Frontend
Backend
(instance 1)
Backend
(instance 2)
Service registry
(Eureka)

22. Hystrix activation
@SpringBootApplication
@EnableCircuitBreaker // protects targeted methods
@EnableEurekaClient
@EnableHystrixDashboard // enables dashboard
public class FrontApplication {
public static void main(String[] args) {
SpringApplication.run(FrontApplication.class,args);
}
}

23. Hystrix dashboard
Source: https://github.com/Netflix/Hystrix

24. Hystrix dashboard explained
Source: https://github.com/Netflix/Hystrix

25. Hystrix dashboard aggregation
Source: https://github.com/Netflix/Hystrix

26. Source: https://github.com/Netflix/Hystrix

27. JavaScript application
Browser
Static content
Frontend
(app.js)
Backend service
REST calls
CORS?
Security?

28. API gateway (reverse proxy)
Browser
Static content
Frontend
(app.js)
Backend service
REST calls
REST calls forwarding

29. API gateway with Spring Cloud
Browser
Static content
Frontend
(app.js)
Backend service
REST calls
REST calls fowarding
Handled by Netflix’s
Zuul in frontend

30. Eureka-aware API gateway
Browser
Static content
Frontend
(app.js)
Backend service
REST calls
REST calls forwarding Eureka
Discovers
Registers

31. Zuul API gateway activation
@SpringBootApplication
@EnableCircuitBreaker
@EnableEurekaClient
@EnableHystrixDashboard
@EnableZuulProxy // activates Zuul API gateway
public class FrontApplication {
public static void main(String[] args) {
SpringApplication.run(FrontApplication.class,args);
}
}

32. Configuration server
HTTP
Service 1
Service 2
Service 3
Configuration
server
Git repository

33. Configuration server
The only local parameter of a service
For DB URL, password, thread pool
size, etc.

34. Configuration server in Spring Boot
@SpringBootApplication
@EnableConfigServer
public class ConfigurationServer {
public static void main(String[] args) {
SpringApplication.run(ConfigurationServer.class,args);
}
}

35. From files to HTTP endpoints
$ tree --charset ascii
.
|-- application.yml
|-- backend-service.yml
`-- front-application.yml

36. Configuration on the client side

37. Packaging with Docker
mvn clean package
# Dockerfile
FROM java:openjdk-8u45-jre
MAINTAINER arnaud.cogoluegnes@zenika.com
RUN mkdir /microservice
ADD ./target /microservice
WORKDIR /microservice
ENTRYPOINT ["java", "-jar", "/microservice/backend-service-1.0.jar"]

38. Wishlist
Packaging
Security
Service discovery
Monitoring
Continuous deployment
Resiliency
Centralized logging
Centralized
configuration

39. Summary
Mature, battle-tested libraries
Help to implement microservices architecture
Transparent for the developper

40. Questions?

41. Thank you!