Microservices Implementations not only with Java. Eberhard Wolff Fellow

Transcription

1 Microservices Implementations not only with Java Eberhard Wolff Fellow

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4 FREE!!!! primer.html ueberblick.html

5 What are Microservices? > Modules providing interfaces > Processes, Containers, virtual machines > Standardized communication: Synchronous, asynchronous, or UI integration > Macro- and Micro-Architecture i.e. clearly defined common, and specific decisions

6 What are Microservices? > Independent Continuous Delivery Pipeline including tests > Standardized Operations (configuration, log analysis, tracing, monitoring, deployment) > Standards on the interface level e.g. not a specific log library > Resilient (compensate failure, crashes ) therefore separate processes, VM, Docker containers

7 Microservices = Extreme Decoupling

8 Operational Complexity Extreme Decoupling

9 Link Micro Service Sync Async Micro Service

10 Synchronous REST Microservices

11 external HTTP internal REST Customer Order Catalog

12 Synchronous Microservices > Service Discovery: IP / port? > Load Balancing: Resilience and independent scaling > Routing: Route external request to microservices > Resilience

13 Synchronous Microservices with Java, Spring Boot / Cloud & the Netflix Stack

14 ewolff/microservice

15 Service Discovery Eureka

16 Why Eureka for Service Discovery? > REST based service registry > Supports replication > Caches on the client > Resilient > Fast > Foundation for other services

17 Eureka Client generic specific > Dependency on spring-cloud-starter-eureka > Automatically registers application

18 public class EurekaApplication { public static void main(string[] args) { SpringApplication.run(EurekaApplication.class, args); } } Add dependency to spring-cloud-starter-eureka-server

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20 Load Balancing Ribbon

21 Ribbon: Client Side Load Balancing Client Load Balancer Server > Decentralized Load Balancing > No bottle neck > Resilient

22 Ribbon Example Via Dependency Injection private LoadBalancerClient loadbalancer; Eureka name ServiceInstance instance = loadbalancer.choose("catalog"); String url = " + instance.gethost() + ": + instance.getport() + "/catalog/"; Need dependency to spring-cloud-starter-ribbon

23 Resilience

24 Timeout > Do call in other thread pool > Won t block request handler > Can implement timeout

25 Circuit Breaker > Called system fails -> open > Open -> do not forward call > Forward calls after a time window

26 Hystrix Configuration > Failure Percentage > Time window until open configurable > Time window to reject requests > > figuration

27 Hystrix & Spring Cloud > Annotation based approach > Annotations of javanica libraries > Simplifies Hystrix > No commands

28 @EnableCircuitBreaker public class OrderApp { public static void main(string[] args) { SpringApplication.run(OrderApp.class, args); } } Need spring-cloud-starter-hystrix

29 @HystrixCommand(fallbackMethod = "getitemscache", commandproperties = = "circuitbreaker.requestvolumethreshold", value = "2") } ) public Collection<Item> findall() { } this.itemscache = pagedresources.getcontent(); return itemscache; Fallback private Collection<Item> getitemscache() { } return itemscache;

30 Zuul Routing

31 Routing > One URL to the outside > Internal: Many Microservices > REST > Or HTML GUI > Hides internal structure (sort of) > Might add filters

32 Automatically maps route to server registered on Eureka i.e. /customer/** to CUSTOMER No configuration Zuul Proxy Customer Order Catalog

33 Netflix Stack > Service Discovery: Eureka > Load Balancing: Ribbon > Routing: Zuul > Resilience: Hystrix > Non-Java microservice: specific clients or sidecar

34 Consul > Service Discovery by Hashicorp > DNS interface > Platform independent > Consul Template can fill out config file templates > e.g. for load balancer > unaware of service discovery

35 ewolff/microservice-consul

36 Kubernetes

37 ewolff/microservicekubernetes

38 Kubernetes > Docker container on a single machine: Not resilient enough > Kubernetes: Run Docker container in cluster > and much more!

39 Pods > Kubernetes runs Pods > Pods = 1..n Docker containers > Shared volumes > and ports

40 Replica Sets > Deployment creates replica set > Replica sets ensure that a certain number of Pods run >...for load balancing / fail over

41 Services > Services ensure access to the Pods > DNS entry > Cluster-wide unique IP address for internal access > External load balancer for external access

42 Pod starts Service Replica Set DNS Cluster IP address Load Balancer Pod creates Deployment

43 Load Balancer Service 1 Service 2 Load Balancer (e.g. Amazon Kubernetes Cluster Server Elastic Load Balancer) Service adds a load balancer Service 1 Service 2 Kubernetes Cluster Server

44 Kubernetes > Service Discovery: DNS > Load Balancing: IP > Routing: Load Balancer or Node Port > Resilience: Hystrix? envoy proxy? > Can use any language

45 No code dependencies on Kubernetes!

46 UI Integration

47 UI Integration > Very powerful > Often overlooked > UI should be part of a microservices > Self-contained System emphasize UI >

48 System 1 System 2 Hyperlinks to navigate between systems.

49 System 1 System 2 Transclusion of content served by another application

50 en/blog/transclusion/

51 Server-side integration Browser Backend 1 UI 1 Frontend Server UI 2 Backend 2 > Centralized aggregation > Bottleneck (runtime/development time)

52 Server-side Integration: Technologies > ESI (Edge Side Include) > E.g. Varnish cache > SSI (Server Side Include) > E.g. Apache httpd, Nginx

53 ESI (Edge Side Includes)... <header>... Logged in as: Ada Lovelace... </header>... <div>... a lot of static content and images... </div>... <div> some dynamic content </div>

54 ESI (Edge Side Includes)... <esi:include src=" />... <div>... a lot of static content and images... </div>... <esi:include src=" />

55 ewolff/scs-esi

56 Client-side integration Browser UI 1 Backend 1 UI 2 Backend 2

57 Client-side Integration: Code Replace <a href= " " class= "embeddable"> with content of document in a <div> (jquery) $("a.embeddable").each(function(i, link) { $("<div />").load(link.href, function(data, status, xhr) { $(link).replacewith(this); }); });

58 Transclusion > Tighter coupling than links > but still very loose > Common CSS > (Avoid) common JavaScript > Layout > Look & Feel

59 ewolff/scs-jquery

60 ewolff/ crimson-assurance-demo

61 Conclusion

62 Operational Complexity Extreme Decoupling

63 Conclusion: Communication > Netflix: Java focus, code dependencies > Kubernetes: No code dependencies > UI Integration more decoupling

64 Links > List of microservices demos (sync, async, UI): > REST vs. Messaging for Microservices

65 to get: Slides + Microservices Primer + Sample Microservices Book + Sample of Continuous Delivery Book Powered by Amazon Lambda & Microservices