microservices with netflix oss & spring cloud - arnaud cogoluègnes
TRANSCRIPT
Microservices withNetflix OSS & Spring Cloud
Arnaud CogoluègnesBerlin, September 19th, 2015
Speaker: Arnaud Cogoluègnes
Netflix OSS and Spring Cloud aren’t
limited to the cloudinfrastructure or container solutions
Netflix OSS and Spring Cloud are
application frameworksalso valid for traditional applications
open source
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)
The use case
Frontend
Backend(instance 1)
Backend(instance 2)
Service registry(Eureka)
Discovers
Registers
Registers
Balances
Netflix stack
Eureka (service registry)Hystrix (circuit breaker)
Ribbon (client load balancer)Zuul (proxy)
....
Spring Cloud
Built on top of Spring BootSpring-ifies some nifty libraries (e.g. Netflix)Provides goodies (e.g. configuration server)Pretty much all you need for microservices
Spring Boot
Spring Framework for the massesNo XML, no container (as you wish)
All the Spring stuff:Dependency injection, transaction
management, REST, ...
Eureka server with Spring Boot
@SpringBootApplication
@EnableEurekaServer // activates Eureka
public class EurekaServer {
public static void main(String[] args) {
SpringApplication.run(EurekaServer.class, args);
}
}
Eureka server
Frontend
Backend(instance 1)
Backend(instance 2)
Service registry(Eureka)
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);
}
}
Eureka client
Frontend
Backend(instance 1)
Backend(instance 2)
Service registry(Eureka)
Discovers
Registers
Registers
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;
}
Client load balancer: Ribbon
Handles HTTP requestsBalances load and detects failures
Resolves services from Eureka
Client load balancing
Frontend
Backend(instance 1)
Backend(instance 2)
Service registry(Eureka)
Balances
Circuit breaker: Hystrix
Why? To prevent cascading failureHow? async, detect failures, open/close
Where? Around services calls
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
}
}
Circuit breaker
Frontend
Backend(instance 1)
Backend(instance 2)
Service registry(Eureka)
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);
}
}
Source: https://github.com/Netflix/Hystrix
Summary
Mature, battle-tested librariesHelp to implement microservices architecture
Transparent for the developper
Questions?
Thank you!