Java Microservices with Netflix OSS & Spring

Transcript

1. JAVA MICROSERVICES WITH NETFLIX OSS & SPRING CONOR SVENSSON
4. SPRING BOOT SPRING BOOT ▸ Stand-alone Spring-based applications ▸ Tomcat embedded container (supports Jetty & JBoss Undertow too) ▸ Starter POMs ▸ Annotation driven
5. SPRING BOOT DEPLOYMENT ▸ Self contained jar ▸ Web application archive ▸ Build targets ▸ $ mvn spring-boot:run ▸ $ gradle bootRun
6. SPRING BOOT
7. ACME HOME LOANS
8. ACME HOME LOANS LOAN APPLICATION EXTERNAL CREDIT SERVICE WEBSITE SERVICE SUBMISSION SERVICE 1 2 3
9. ACME HOME LOANS
10. ACME HOME LOANS
11. ACME HOME LOANS
12. SPRING BOOT TESTING ▸ spring-boot-starter-test starter POM provides: ▸ Spring Test ▸ Unit ▸ Hamcrest + Assert4J (v1.4) ▸ Mockito ▸ MockMvc ▸ @WebIntegrationTest
15. SPRING BOOT CONFIGURATION BEANS
17. SPRING CLOUD SPRING CLOUD ▸ Microservice friendly components ▸ Distributed & versioned configuration ▸ Service discovery ▸ Dynamic routing ▸ Circuit breakers ▸ Distributed messaging ▸ Getting started:
18. SPRING CLOUD SPRING CLOUD ▸ Config ▸ Netflix ▸ Bus ▸ Cloud Foundry ▸ Cluster ▸ Consul ▸ Security ▸ Sleuth ▸ Data Flow ▸ Stream ▸ Modules ▸ Task ▸ Zookeeper ▸ AWS ▸ Connectors ▸ CLI
19. SPRING CLOUD CONFIG SERVER ▸ Git hosted configuration repository ▸ SVN & filesystem also supported (see implementations of org.springframework.cloud.config.server.EnvironmentR epository) ▸ Multiple security options w/Spring Security (HTTP Basic -> OAuth bearer tokens) ▸ Push updates via Spring Cloud Bus
20. SPRING CLOUD CONFIG SERVER
21. SPRING CLOUD CONFIG SERVER CONFIGURATION application.yml:
22. SPRING CLOUD CLIENT CONFIGURATION FILE website.yml:
23. SPRING CLOUD RESOURCE FORMAT /{application}/{profile}[/{label}] /{application}-{profile}.yml /{label}/{application}-{profile}.yml /{application}-{profile}.properties /{label}/{application}-{profile}.properties (label: master by default)
24. SPRING CLOUD RESOLVED CONFIGURATION
25. SPRING CLOUD SHARED RESOURCES ▸ Place in application.yml in root of configuration repo ▸ Profile specific configuration always takes precedence over shared ▸ E.g. Eureka server (more on this shortly)
26. SPRING CLOUD CLIENT CONFIGURATION bootstrap.yml:
27. SPRING CLOUD CLIENT PROFILES ▸ Annotate classes to associate with a profile ▸ @Profile(“…”) ▸ Configuration (bootstrap/application properties) ▸ spring.profiles.active = … ▸ Command line ▸ -Dspring.profiles.active=… ▸ Environment variable ▸ SPRING_PROFILES_ACTIVE=…
28. SPRING CLOUD RESOLVED CLIENT CONFIGURATION
29. SPRING CLOUD CONFIG SERVER GOTCHAS ▸ Client’s don’t fail on Config Server failure - boot with defaults (e.g. port 8080) ▸ To enable use spring.cloud.config.failFast=true ▸ Enable retries: ▸ Add spring-retry and spring-boot-starter-aop ▸ spring.cloud.config.retry.
31. NETFLIX OSS + SPRING SPRING CLOUD NETFLIX ▸ Service discovery (Eureka) ▸ Client side load balancing (Ribbon) ▸ Dynamic routing (Zuul) ▸ Circuit breaker (Hystrix) ▸ + a few others…
32. NETFLIX OSS + SPRING EUREKA ▸ Service discovery client & server ▸ Maintains registry of clients with metadata ▸ Host/port ▸ Health indicator URL ▸ Client heartbeats (30 sec default - changing not encouraged) ▸ Lease renewed with server ▸ Service available when client & server(s) metadata cache all in sync ▸ Can take up to 3 heart beats
33. NETFLIX OSS + SPRING EUREKA SERVER
34. NETFLIX OSS + SPRING EUREKA SERVER DASHBOARD
35. NETFLIX OSS + SPRING EUREKA CLIENT SETUP @EnableEurekaClient annotation application.yml in Config Server repo
36. NETFLIX OSS + SPRING RIBBON ▸ Client side loan balancer ▸ Can delegate to Eureka for server lists ▸ Or list servers ▸ stores.ribbon.listOfServers=… + ribbon.eureka.enabled=false
37. NETFLIX OSS + SPRING RIBBON USAGE ▸ Via RestTemplate ▸ No different to normal usage - Spring Cloud Commons abstraction ▸ Qualifier’s required if using regular & Ribbon enabled RestTemplate
38. NETFLIX OSS + SPRING ZUUL ▸ JVM based router & load balancer ▸ Provides single point of entry to services ▸ Including single point of authentication ▸ By default creates route for every service in Eureka ▸ Refer to http://localhost/credit-service routes to http://credit- service ▸ Filters provide limited entry points to system
39. NETFLIX OSS + SPRING ZUUL SERVER CREATION ‣ Include dependency spring-cloud-starter-zuul ‣ @EnableZuulProxy application annotation ‣ E.g. Allow access only to credit-service
40. NETFLIX OSS + SPRING SIDECAR ▸ Non-JVM access to components via Zuul proxy ▸ Setup Spring Boot application with @EnableSidecar ▸ Configure for your service: ▸ sidecar.port=… + sidecar.health-ui=… ▸ Access all services by Zuul URL (Sidecar running on port 80) ▸ http://localhost/config-server
41. NETFLIX OSS + SPRING HYSTRIX ▸ Circuit breaker ▸ Threshold breached (20 failures in 5 seconds) => breaker kicks in ▸ Default timeout threshold 1 second ▸ Per dependency thread pools ▸ Async command support (not Spring @Async) ▸ Sync or async fallback
42. NETFLIX OSS + SPRING HYSTRIX CLIENT ▸ @EnableCircuitBreaker application annotation ▸ @HystrixCommand on applicable methods
43. NETFLIX OSS + SPRING
44. NETFLIX OSS + SPRING HYSTRIX STREAM - PRE-REQUESTS
45. NETFLIX OSS + SPRING HYSTRIX STREAM - POST-REQUESTS
46. NETFLIX OSS + SPRING HYSTRIX DASHBOARD
47. NETFLIX OSS + SPRING HYSTRIX STREAM
48. NETFLIX OSS + SPRING HYSTRIX DASHBOARD
49. NETFLIX OSS + SPRING TURBINE - AGGREGATE MULTIPLE HYSTRIX CLIENTS
50. NETFLIX OSS + SPRING MONITORING ▸ Add dependency spring-boot-actuator ▸ Makes available various application metrics via /metrics endpoint ▸ Integration also available with DropWizard metrics (add dependency) ▸ Spring Cloud ▸ Spectator (supersedes Servo) - metrics collection ▸ Atlas - metrics backend
51. NETFLIX OSS + SPRING
52. NETFLIX OSS + SPRING LOGGING ▸ Logback is the default choice ▸ Alternative starters are provided ▸ Using alternatives (such as log4j2) requires exclusions throughout the starter POMs
53. NETFLIX OSS + SPRING DOWNSIDES ▸ A lot of magic - e.g. CORS filters ▸ ADD (Annotation driven development) ▸ Dependency management ▸ RestTemplates - Ribbon enabled != Standard HTTP ▸ Lack of proper polygot support - libraries are in Java (Sidecar is OK as a middle ground) ▸ Spring Hystrix documentation is pretty light
54. NETFLIX OSS + SPRING ALTHOUGH…
55. NETFLIX OSS + SPRING RESOURCES ▸ Spring Cloud documentation - http://projects.spring.io/spring-cloud/spring-cloud.html ▸ Spring Boot sample projects - https://github.com/spring-projects/spring-boot/tree/ master/spring-boot-samples ▸ Spring Cloud sample projects - https://github.com/spring-cloud-samples ▸ Hystrix annotations - https://github.com/Netflix/Hystrix/tree/master/hystrix-contrib/ hystrix-javanica ▸ Useful demonstration of Spring Cloud usage - http://callistaenterprise.se/blogg/teknik/ 2015/05/20/blog-series-building-microservices/ ▸ Spring project dependency selector - http://start.spring.io/ ▸ Code to accompany this talk - https://github.com/conor10/homeloans ▸ https://www.huffle.com.au
56. NETFLIX OSS + SPRING THANKS conor@huffle.com.au