The document discusses the development of reactive microservices using Quarkus, highlighting technologies such as Vert.x and MicroProfile for building responsive systems. It emphasizes the benefits of reactive programming for scalable applications, while outlining an example architecture and components involved in a typical application setup. Additionally, it encourages the exploration of a cloud-native starter project for hands-on experience.

1. Developing reactive
Microservices with Quarkus
Niklas Heidloff
Developer Advocate, IBM
@nheidloff

2. Reactive Manifesto
Reactive Systems
Reactive Programming
Functional Programming
Asynchronous Programming
Reactive Streams
Reactive Operators
Buzzword Bingo
#IBMDeveloper github.com/ibm/cloud-native-starter@nheidloff

3. ?

4. Reactive REST EndpointsReactive Web Application
Let’s make it concrete
#IBMDeveloper github.com/ibm/cloud-native-starter@nheidloff

5. Reactive Web Application

6. Reactive REST Endpoints

7. Reactive Manifesto
Responsive
Message Driven
Elastic Resilient
#IBMDeveloper github.com/ibm/cloud-native-starter@nheidloff

8. Reactive Systems
!=
Reactive Programming
#IBMDeveloper github.com/ibm/cloud-native-starter@nheidloff

9. Reactive Programming is …

10. Reactive Programming is ‘unusual’

11. Reactive Programming is ‘unusual’

12. Reactive Programming is ‘unusual’

13. Javadoc to the Rescue?

14. Reactive programming is
extremely powerful, but
not the right tool for
all jobs!
#IBMDeveloper github.com/ibm/cloud-native-starter@nheidloff

15. Technologies to build reactive Applications
Quarkus
Vert.x
MicroProfile
Kubernetes
#IBMDeveloper github.com/ibm/cloud-native-starter@nheidloff

16. Quarkus – Supersonic Subatomic Java

17. Quarkus using OpenJ9

18. “Optimizing Enterprise Java
for a Microservices
Architecture.“
“[...] by innovating [...] with a
goal of standardization.”
microprofile.io
#IBMDeveloper github.com/ibm/cloud-native-starter@nheidloff

19. “Eclipse Vert.x is a tool-kit for
building reactive applications
on the JVM.”
“Eclipse Vert.x is event
driven and non blocking [...]
and lets your app scale with
minimal hardware.”
vertx.io
#IBMDeveloper github.com/ibm/cloud-native-starter@nheidloff

20. “Kubernetes (K8s) is an open-
source system for automating
deployment, scaling, and
management of containerized
applications.”
kubernetes.io
#IBMDeveloper github.com/ibm/cloud-native-starter@nheidloff

21. Example Application

22. Architecture
Web-App
KafkaWeb-API
Articles
Authors
Web-App
Postgres
Clients
Microservices Infrastructure Components
Kubernetes
API Client

23. Reactive Web Application

24. Notifications for Web Applications
Web-App
KafkaWeb-API
Articles
Clients
Microservices Infrastructure Components
Kubernetes
API Client
1.
4. 3.
2.
Web-App
Postgres
Authors

25. MicroProfile Reactive Messaging
Web-App
KafkaWeb-API
Articles
Authors
Web-App
Postgres
Clients
Microservices Infrastructure Components
Kubernetes
API Client

26. MicroProfile Reactive Messaging

27. MicroProfile Reactive Messaging

28. Reactive Streams is an
initiative to provide a
standard for asynchronous
stream processing [...] aimed
at runtime environments
(JVM and JavaScript).”
reactive-streams.org
#IBMDeveloper github.com/ibm/cloud-native-starter@nheidloff
Components:
1. Subscriber
2. Publisher
3. Processor
Java:
• JDK9: java.util.concurrent.Flow
• MicroProfile: org.reactivestreams

29. MicroProfile Reactive Messaging
Subscriber
Publisher
Processor

30. Server Sent Events
Web-App
KafkaWeb-API
Articles
Authors
Web-App
Postgres
Clients
Microservices Infrastructure Components
Kubernetes
API Client

31. Server Sent Events

32. Server Sent Events

33. Server Sent Events
Java JavaScript

34. Server Sent Events

35. Vert.x Event Bus
Web-App
KafkaWeb-API
Articles
Authors
Web-App
Postgres
Clients
Microservices Infrastructure Components
Kubernetes
API Client

36. @nheidloff
Clean Architecture
1. APIs
REST endpoints and messaging
2. Business
Logic of services and entities
3. Data
Access to databases or other services

37. Vert.x Event Bus
Business Layer
API Layer

38. Vert.x Event Bus

39. Vert.x Event Bus

40. Vert.x Event Bus

41. Kafka API
Web-App
KafkaWeb-API
Articles
Authors
Web-App
Postgres
Clients
Microservices Infrastructure Components
Kubernetes
API Client

42. Kafka API

43. Kafka API

44. Kafka API

45. Reactive REST Endpoints

46. Reactive REST Endpoint
Web-App
KafkaWeb-API
Articles
Authors
Web-App
Postgres
Clients
Microservices Infrastructure Components
Kubernetes
API Client

47. Reactive REST Endpoint

48. Completion Stage

49. Completion Stage

50. Completion Stage and Completable Future

51. Completion Stage and Completable Future

52. Chained Completion Stages

53. Chained Completion Stages

54. Chained Completion Stages

55. Chained Completion Stages

56. Exception Handling with imperative Code

57. Exception Handling with reactive Code

58. Exception Handling with reactive Code

59. Exception Handling with reactive Code

60. Exception Handling with reactive Code

61. Exception Handling with reactive Code

62. Timeouts

63. Timeouts

64. Invoking REST APIs asynchronously
Web-App
KafkaWeb-API
Articles
Authors
Web-App
Postgres
Clients
Microservices Infrastructure Components
Kubernetes
API Client

65. MicroProfile Client

66. MicroProfile Client

67. MicroProfile Client

68. MicroProfile Client

69. MicroProfile Client

70. MicroProfile Client

71. Try out the end-to-end
microservices example
cloud-native-starter!
#IBMDeveloper github.com/ibm/cloud-native-starter@nheidloff

72. Focus on Developer Experience

73. Several Kubernetes Environments

74. IBM Cloud Kubernetes Service including Istio and Knative

75. IBM Developer
developer.ibm.com
IBM Cloud Lite account
ibm.biz/nheidloff
IBM loves open source
Kubernetes
OpenJ9
MicroProfile
Quarkus
Reactive systems improve
user experiences and are
more efficient
Summary
Get the code à
@nheidloff #IBMDeveloper github.com/ibm/cloud-native-starter