Microservices mit Java, Spring Boot & Spring Cloud. Eberhard Wolff

Transcription

1 Microservices mit Java, Spring Boot & Spring Cloud Eberhard Wolff

2 What are Microservices?

3 Micro Service: Definition > Small > Independent deployment units > i.e. processes or VMs > Any technology > Any infrastructure Micro Service Server Micro Service Server

4 Components Collaborate Link Micro Service REST Messaging Micro Service Data Replication

5 Infrastructure > Lots of services > Need infrastructure > Easy to create a new project > REST integrated > Messaging supported > Uniform operations

6 Spring Boot Demo

7 Simple Infrastructure > One pom.xml > Gradle / Ant > Very few dependencies > One plug in > Versions defined for you

8 REST Integrated > Support in Spring MVC > As we have seen > Also support for JAX-RS > Jersey

9 Messaging Support > Numerous Spring Boot Starter > AMQP (RabbitMQ) > HornetQ (JMS) > ActiveMQ (JMS, no starter)

10 Messaging Support > Spring JMS abstraction > Message driven POJOs > Scalable > Simplify sending JMS > Can use other libs, too! > Boot: everything Spring / Java can do

11 Infrastructure > More services > Need infrastructure > Easy to create a new project > REST integrated > Messaging supported > Simple deployment > Uniform operations

12 Deploy > Just package everything in an executable JAR > or a WAR > Based on Maven, Ant or Gradle > Add configuration

13 Spring Boot Deploy Demo

14 Deploy > Install a basic machine > Install Java > Copy over JAR > Optional: Make it a Linux Service (1.3) > Optional: Create application.properties

15 Infrastructure > More services > Need infrastructure > Easy to create a new project > REST integrated > Messaging supported > Simple deployment > Uniform operations

16 Spring Boot Actuator > Provide information about the application > Via HTTP / JSON > Can be evaluated by monitoring tools etc. > Another alternative approach to monitoring

17 Spring Boot Actuator Demo

18 Infrastructure > More services > Need infrastructure > Easy to create a new project > REST integrated > Messaging supported > Simple deployment > Uniform operations

19 Spring Cloud

20 Based on Spring Boot

21 Spring Cloud > Spring support for Amazon Web Services > Connector for Heroku PaaS > and Cloud Foundry PaaS > The rest of Spring Cloud is for Microservices

22 Coordinating Microservices

23 > Must find each other Microservice Microservice

24 Service Discovery Eureka

25 Why Eureka? > REST based service registry > Supports replication > Caches on the client > Resilient > Fast > but not consistent > Foundation for other services

26 Eureka Client in Spring Cloud generic more specific > Dependency to spring-cloud-starter-eureka > Automatically registers application

27

28 > Must find each other > Route calls to a service Microservice Microservice

29 Zuul Routing

30 Routing > One URL to the outside > Internal: Many Microservices > REST > Or HTML GUI

31 Automatically maps route to server registered on Eureka i.e. /customer/** to CUSTOMER No configuration Zuul Proxy Can add filters etc Customer Order Catalog

32 > Must find each other > Route calls to a service > Configuration Microservice Microservice

33 Spring Cloud Config

34 Configuration > Spring Cloud Config > Central configuration > Dynamic updates > Can use git backend > I prefer immutable server > & DevOps tools (Docker, Chef )

35 Spring Cloud Bus > Pushed config updates > or individual message > I prefer a messaging solution > Independent from Spring

36 > Must find each other > Route calls to a service > Configuration > Security Microservice Microservice

37 Spring Cloud Security

38 Spring Cloud Security > Single Sign On via OAuth2 > Forward token e.g. via RestTemplate > Support for Zuul > Very valuable!

39 Implementing Microservices

40 > Load Balancing Microservice Microservice

41 Load Balancing Ribbon

42 Ribbon: Client Side Load Balancing Client Load Balancer Server > Decentralized Load Balancing > No bottle neck > Resilient > Hard to consider metrics / health > Data might be inconsistent

43 RestTemplate & Load Balancing Enable Ribbon Left out other = "ribbonapp") public class RibbonApp private RestTemplate resttemplate; Standard Spring REST client Can also use Ribbon API } public void callmicroservice() { } Store store = resttemplate. getforobject(" Store.class); Eureka name or server list

44 > Load Balancing > Resilience Microservice Microservice

45 Hystrix Resilience

46 Hystrix > Enable resilient applications > Do call in other thread pool > Won t block request handler > Can implement timeout

47 Hystrix > Circuit Breaker > If call system fail open > If open do not forward call > Forward calls after a time window > System won t be swamped with requests

48 Hystrix / Spring Cloud > Annotation based approach > Annotations of javanica libraries > Java Proxies automatically created > Simplifies Hystrix dramatically > No commands etc

49 = "getitemscache") public Collection<Item> findall() { this.itemscache = pagedresources.getcontent(); return itemscache; } private Collection<Item> getitemscache() { } return itemscache;

50 Stream via http Hystrix Dashboard Circuit Breaker status Thread Pool status

51 Conclusion

52 Infrastructure > Easy to create a new project > REST integrated > Messaging supported > Simple deployment > Uniform operations

53 Spring Cloud > Eureka: Service Discovery > Zuul: Route calls to a service > Spring Cloud Config: Configuration > Ribbon: Load Balancing > Hystrix: Resilience

54 Links > > > > microservices >

55

56 Thank