Criando Micro-serviços Reativos com JavaRodrigo Cândido da Silva

@rcandidosilva

About Me• Software Architect

• http://integritastech.com • JUG Leader do GUJavaSC

• http://gujavasc.org • Twitter

• @rcandidosilva • Contatos

• http://rodrigocandido.me

Agenda• Monolito vs. Micro-serviços • Manifesto Reativo • Resiliência • Message-driven • Demo • Perguntas

Monolito vs. Micro-serviços

Micro-serviços

• Pequenos • Deployment interdependente • Independente de tecnologia • Infra-estrutura separada

"Small independent component with well-defined boundaries that’s doing one thing, but

doing it well"

Manifesto Reativo

Resiliência• Como suportar isso com micro-serviços?

• Central point of configuration • Service registry and discovery • Routing features • Load balancing • Failover • Monitoring

Spring BootSpring Cloud

Spring Cloud + Netflix OSS

Spring Cloud + Netflix OSS“Casamento perfeito para criação de micro-

serviços resilientes“

Gerenciamento de Configuração Spring Cloud Config + Bus

Descoberta de Serviços Netflix Eureka

Balanceamento de Carga Netflix Ribbon

Circuit Breaker Netflix Hystrix + Turbine

Proxy Server Netflix Zuul

Segurança Spring Cloud Security

Spring Cloud Config

Netflix Eureka

Netflix Ribbon

Netflix Hystrix• Circuit Breaker Pattern

Hystrix Dashboard

Netflix Zuul

Spring Cloud Security

Discovery

Client Relying Party

Resource Server

Get an access token

& an ID Token (JWT)

Use an access token

Authorization Server

Iden.tyProviderorIDPor

OpenIDProviderorOP

Authorization Endpoint

Token Endpoint

Important Stuff

Userinfo Endpoint

Registration Endpoint

JWKS Endpoint

JWKS Endpoint

Validate (JWT)

ID Token

/.well-known /webfinger /openid-configura.on

Check Session IFrame

End Session Endpoint

Message-Driven • Como suportar isso com micro-serviços?

• Comunicação assíncrona • Non blocking I/O • Distribuição • Consistência • Event sourcing • CQRS

Reactive Programming• Asynchronous communication and data streams

• reactive-streams.org

Alternativas Reativas com Java EE

JMS EJB 3

Message-Driven Beans

Asynchronous Session Beans

CDIEvents

Observers

ServletAsynchronous

NIO

JAX-RSAsync on Server

Async on Client

WebSocket

Async Remote Endpoints Concurrency

Utilities

Project Reactor• Biblioteca para implementação de non-blocking apps • Interage com Java 8 functional API • Oferece duas composable API reativas

• Flux[N] and Mono[0|1] • Suporta escalabilidade in-memory roteando com Bus extensions

• Suporte portável para micro-serviços

REST Endpoint@RestControllerpublic class UserRestController {

private static final List<User> users = new ArrayList<>();

static { users.add(new User(1, "Rodrigo", "C", "da Silva")); users.add(new User(2, "Israel", "B", "Rodriguez")); users.add(new User(3, "Bruno", "", "Souza")); users.add(new User(4, "Edson", "", "Yanaga")); }

@RequestMapping(method = RequestMethod.GET, value = "/users") public List<User> getUsers() { return users; }

@RequestMapping(method = RequestMethod.GET, value = "/user/{id}") public User getUser(@PathVariable("id") Integer id) { return users.stream().filter(g -> g.getId() == id) .collect(Collectors.toList()).get(0); }

}

REST Proxy@Componentpublic class UserServiceProxy {

@Autowired UserService service;

@HystrixCommand(fallbackMethod = "defaultUsersObservable") public Observable<List<User>> getUsersObservable() { return new ObservableResult<List<User>>() { @Override public List<User> invoke() { return service.getUsers(); } }; }

public Observable<User> defaultUsersObservable() { return null; }} @FeignClient("USER-SERVICE")

public interface UserService {

@RequestMapping(value = "/users", method = RequestMethod.GET) List<User> getUsers();

@RequestMapping(value = "/user/{id}", method = RequestMethod.GET) User getUser(@PathVariable("id") Integer id);}

REST Async Client

@RestControllerpublic class APIController {

@Autowired GroupServiceProxy groupService;

@Autowired UserServiceProxy userService;

@RequestMapping(method = RequestMethod.GET, value = "/userGroups") public UserGroup getUserGroups() { Observable<List<Group>> groups = groupService.getGroupsObservable(); Observable<List<User>> users = userService.getUsersObservable();

Observable<UserGroup> userGroupObservable = Observable.zip(groups, users, (g, u) -> new UserGroup(u, g));

return userGroupObservable.toList().toBlocking().single().get(0); }

}

Demo• Reactive Microservices • https://github.com/rcandidosilva/reactive-microservices

Outras Alternativas

Perguntas

?

Referências• http://projects.spring.io/spring-boot/ • http://projects.spring.io/spring-cloud/ • https://netflix.github.io/ • http://www.reactive-streams.org/ • http://www.reactivemanifesto.org/ • https://github.com/reactivemanifesto/website-manifesto/tree/master/public/pdf • https://projectreactor.io/ • http://reactivex.io/ • http://www.kennybastani.com/2016/04/event-sourcing-microservices-spring-

cloud.html

Muito Obrigado! @rcandidosilva

rodrigocandido.me