Microservices - not just with Java

This presentation show several options how to implement microservices: the Netflix stack, Consul, and Kubernetes. Also integration options like REST and UI integration are covered.

Transcript

1. Microservices – Implementations not only with Java Eberhard Wolff @ewolff Fellow
2. http://continuous-delivery-buch.de/ http://continuous-delivery-book.com/
3. http://microservices-buch.de/ http://microservices-book.com/
4. http://microservices-book.com/ primer.html http://microservices-buch.de/ ueberblick.html FREE!!!!
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. Micro Service Micro Service Link Sync Async
10. Synchronous REST Microservices
11. Customer Order Catalog REST internal HTTP external
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 Bott / Cloud & the Netflix Stack
14. https://github.com/ 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 > @EnableDiscoveryClient: generic > @EnableEurekaClient: specific > Dependency on spring-cloud-starter-eureka > Automatically registers application
18. Eureka Server @EnableEurekaServer @EnableAutoConfiguration public class EurekaApplication { public static void main(String[] args) { SpringApplication.run(EurekaApplication.class, args); } } Add dependency to spring-cloud-starter-eureka-server
20. Load Balancing Ribbon
21. Proxy Load Balancing > Centralized Load Balancing > Can become bottle neck > Single point of failure Load Balancer Server Client
22. Client Ribbon: Client Side Load Balancing > Decentralized Load Balancing > No bottle neck > Resilient > Can consider response time Load Balancer Server
23. Ribbon Example private LoadBalancerClient loadBalancer; … ServiceInstance instance = loadBalancer.choose("CATALOG"); String url = "http://" + instance.getHost() + ":” + instance.getPort() + "/catalog/"; Via Dependency Injection Eureka name Need dependency to spring-cloud-starter-ribbon
24. Resilience
25. Timeout > Do call in other thread pool > Won’t block request handler > Can implement timeout
26. Circuit Breaker > Called system fails -> open > Open -> do not forward call > Forward calls after a time window
27. Hystrix Configuration > Failure Percentage > Time window until open configurable > Time window to reject requests > … > https://github.com/Netflix/Hystrix/wiki/Con figuration
28. Hystrix & Spring Cloud > Annotation based approach > Annotations of javanica libraries > Simplifies Hystrix > No commands
29. @SpringBootApplication @EnableDiscoveryClient @EnableCircuitBreaker public class OrderApp { public static void main(String[] args) { SpringApplication.run(OrderApp.class, args); } } Enable Hystrix Need spring-cloud-starter-hystrix
30. @HystrixCommand(fallbackMethod = "getItemsCache", commandProperties = { @HystrixProperty(name = "circuitBreaker.requestVolumeThreshold", value = "2") } ) public Collection<Item> findAll() { … this.itemsCache = pagedResources.getContent(); return itemsCache; } private Collection<Item> getItemsCache() { return itemsCache; } Fallback
31. Zuul Routing
32. Routing > One URL to the outside > Internal: Many Microservices > REST > Or HTML GUI > Hides internal structure (sort of) > Might add filters
33. Customer Order Catalog Zuul Proxy Automatically maps route to server registered on Eureka i.e. /customer/** to CUSTOMER No configuration
34. Netflix Stack > Service Discovery: Eureka > Load Balancing: Ribbon > Routing: Zuul > Resilience: Hystrix > Non-Java microservice: specific clients or sidecar
35. 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
36. https://github.com/ ewolff/microservice-consul
37. Kubernetes
38. https://github.com/ ewolff/microservice- kubernetes
39. Kubernetes > Docker container on a single machine: Not resilient enough > Kubernetes: Run Docker container in cluster > …and much more!
40. Pods > Kubernetes runs Pods > Pods = 1..n Docker containers > Shared volumes > …and ports
41. Replica Sets > Deployment creates replica set > Replica sets ensure that a certain number of Pods run > ...for load balancing / fail over
42. Services > Services ensure access to the Pods > DNS entry > Cluster-wide unique IP address for internal access > Node port … > … or external load balancer for external access
43. Replica Set Pod Pod Service starts DNS Cluster IP address Load Balancer Deployment creates
44. Load Balancer Kubernetes Cluster Server Service 1 Service 2 Kubernetes Cluster Server Service 1 Service 2 Service adds a load balancer Load Balancer (e.g. Amazon Elastic Load Balancer)
45. Kubernetes > Service Discovery: DNS > Load Balancing: IP > Routing: Load Balancer or Node Port > Resilience: Hystrix? envoy proxy? > Can use any language
46. No code dependencies on Kubernetes!
47. UI Integration
48. UI Integration > Very powerful > Often overlooked > UI should be part of a microservices > Self-contained System emphasize UI > http://scs-architecture.org/
49. Hyperlinks to navigate between systems. System 1 System 2
50. Transclusion of content served by another application System 1 System 2
51. https://www.innoq.com/ en/blog/transclusion/
52. UI Integration > Extremely decoupled > Here is a link: http://ewolff.com > No need to know anything else about the system > What about more complex transclusion?
53. Server-side integration > Centralized aggregation > Bottleneck (runtime/development time) Browser UI 1 UI 2 Frontend Server Backend 1 Backend 2
54. Server-side Integration: Technologies > ESI (Edge Side Include) > E.g. Varnish cache > SSI (Server Side Include) > E.g. Apache httpd, Nginx
55. 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>
56. ESI (Edge Side Includes) ... <esi:include src="http://example.com/header" /> ... <div> ... a lot of static content and images ... </div> ... <esi:include src="http://example.com/dynamic" /> http://www.w3.org/TR/esi-lang
57. https://github.com/ ewolff/SCS-ESI
58. Client-side integration Browser UI 1 UI 2 Backend 1 Backend 2
59. Client-side Integration: Code $("a.embeddable").each(function(i, link) { $("<div />").load(link.href, function(data, status, xhr) { $(link).replaceWith(this); }); }); Replace <a href= " " class= "embeddable"> with content of document in a <div> (jQuery)
60. Transclusion > Tighter coupling than links > …but still very loose > Common CSS > (Avoid) common JavaScript > Layout > Look & Feel
61. https://github.com/ ewolff/SCS-jQuery
62. Morgen 11:20
63. Operational Complexity Extreme Decoupling
64. Can you simplify operations?
65. Reduce Operational Complexity > Go provides statically linked binaries > No additional binaries > No additional dynamic libraries > Docker container just contains one file > No Linux distribution > Simplest deployment
66. Amazon Lambda
67. Amazon Lambda > Service in the Amazon Cloud > Allows you to install individual functions > Java, JavaScript, Python, C#
68. Amazon Lambda > Upload code (web / command line) > Use S3 bucket (Simple Storage Service) > Edit in the browser
70. Lambda Function Command Line (Tests) Event from Amazon Service i.e. database trigger Monitoring Event API Gateway (e.g. REST)
71. Monitoring built-in!
74. Lambda simplifies operations and deployment.
75. Lambda allows many small services.
77. Bundles > Partition system into "bundles” > Bundles can be installed, started, stopped, uninstalled and updated > ...at runtime
78. Code Sharing > Bundles can export and import packages > Updating code requires other bundles to start fresh
79. Services > Bundles can publish services… dynamically! > Service = Java Object > Service Registry allows other bundles to consume services > Services come and go at runtime > Quite easy with OSGi Blueprints or OSGi Declarative Services
80. Calling Bundle Bundle (interface code) Bundle (implementation and service) Service Package (interface code) Package (interface code) Update to service in running application
81. Operational Complexity Extreme Decoupling
83. Deployment > JARs e.g. for EJBs > WARs e.g. for web application > EARs for JARs and WARs > Completely separated code
84. Microservices > Microservice = 1 WAR / JAR + application server (Spring / plain Java EE) > Microservice = Fat JAR (Spring Boot / Wildfly Swarm) > Per microservice decision > App server more complex and dead > https://www.slideshare.net/ewolff/java- application-servers-are-dead
85. Alternative > Might help: Deployment model > i.e. application server > More services per JVM
86. Tomcat Java EE Server order.war customer.war catalog.war Customer
87. Operational Complexity Extreme Decoupling
88. Conclusion
89. Operational Complexity Extreme Decoupling
90. Conclusion: Communication > Netflix: Java focus, code dependencies > Kubernetes: No code dependencies > UI Integration more decoupling
91. Conclusion: Operations > Go reduces deployment complexity > Java EE and OSGi: less operational complexity, less decoupling > UI Integration more decoupling
92. Links > List of microservices demos (sync, async, UI): http://ewolff.com/microservices-demos.html > REST vs. Messaging for Microservices https://www.slideshare.net/ewolff/rest-vs- messaging-for-microservices
93. EMail herbstcampus2017@ewolff.com to get: Slides + Microservices Primer + Sample Microservices Book + Sample of Continuous Delivery Book Powered by Amazon Lambda & Microservices