Netflix OSS and Spring Cloud provide frameworks for building microservice applications that can run on various infrastructures. They include libraries like Eureka for service registration and discovery, Ribbon for load balancing, and Hystrix for fault tolerance via circuit breaking. Spring Cloud builds on Spring Boot and "Spring-ifies" Netflix libraries, providing a simple way to add features like configuration management and monitoring dashboards. These frameworks help developers implement microservices patterns in a transparent manner.

1. Microservices with
Netflix OSS & Spring Cloud
Arnaud Cogoluègnes
Berlin, September 19th, 2015

2. Speaker: Arnaud Cogoluègnes

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

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

5. 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)

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

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

8. 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

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

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

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

12. 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);
}
}

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

14. 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;
}

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

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

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

18. 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
}
}

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

20. 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);
}
}

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

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

23. Questions?

24. Thank you!