SpringOne 2021 Session Title: Resilient and Adaptable Systems with Cloud Native APIs Speakers: Olga Maciaszek-Sharma, Senior Member of Technical Staff at VMware; Spencer Gibb, Spring Cloud Core Lead at VMware

1. Spencer Gibb @spencerbgibb
Olga Maciaszek-Sharma @olga_maciaszek
Resilient and Adaptable Systems
with Cloud Native APIs
Copyright © 2020 VMware, Inc. or its affiliates.
1

2. Cover w/ Image
Agenda
● What is a Cloud-Native API?
● Protocols
● Gateways
● Architecture
● Demo
● Q+A
2

3. What is a Cloud-Native API?
3

4. The API is the product
https://techcrunch.com/2019/09/06/apis-are-the-next-big-saas-wave/
API First
4

5. IoT devices
API First: The API is the product
WWW
Mobile Apps Web apps
5

6. API First: The API is the product
6

7. API First: The API is the product
Streaming Shopping Shipping
7

8. Systems Driven by the API
8

9. Systems Driven by the API
Apps Instances &
Networks
Load
Balancer
9

10. Systems Driven by the API
Resilience Fault
Tolerance
Rate
Limiting
10

11. The API is greater than the sum of its parts
11

12. Serverless
12

13. Server-side architecture run in
stateless, event-triggered, ephemeral
compute containers.*
* https://martinfowler.com/articles/serverless.html
13

14. Backend as a Service
14

15. Function as a Service
15

16. Event-Driven
16

17. Infrastructure management handled by
cloud providers
17

18. Automatic scaling
Built-in high availability
Pay-for-use billing model
18

19. Emphasis on short startup and low
memory footprint
19

20. Higher system complexity
Complex monitoring and tracing
Risk of vendor locks
Last 10% trap
20

21. Spring Cloud Function
@SpringBootApplication
public class Application {
[...]
@Bean
public Function<String, String> uppercase() {
return value -> value.toUpperCase();
}}
21

22. Tanzu Application Platform
22

23. Efficiency/Speed
23

24. Responsiveness is important
Optimize for availability and speed
24

25. Protocols
25

26. Infrastructure is Important.
Scaling and Resiliency
26

27. Spring Ecosystem
allows focus on core business.
Speed to market matters.
27

28. Evolving
28

29. Intra-service communication as part of
functionalities’ implementation
29

30. APIs within systems
30

31. Backward compatibility
Addition only
Tolerant consumers
Deferred updates
31

32. Consumer-Driven Contracts
Collaborative
Scenario-based
Integration testing
Backwards compatibility testing
32

33. 'Spring Cloud Contract
request {
method 'PUT'
url '/fraudcheck'
body([
"client.id": $(regex('[0-9]{10}')),
loanAmount : 99999
])
headers {
contentType('application/json')
}
}
response {
status OK()
body([
fraudCheckStatus : "FRAUD",
"rejection.reason": "Amount too high"
])
headers {
contentType('application/json')
}
}
33

34. Protocols
34

35. HTTP
35

36. Resource-oriented
36

37. Simple and straightforward
37

38. Client-Server/ Request-Response
Synchronous
Head-of-line blocking
38

39. Text-based
The internet is running in debug mode*
* http://java-is-the-new-c.blogspot.com/2014/10/why-protocols-are-messy-concept.html
39

40. HTTP/2
Binary
Multiplexed
Headers compression
Server Push
40

41. Upcoming: HTTP/3
QUIC-based
41

42. Messaging
42

43. Rabbitmq & Kafka
offer distributed message brokers
and streaming semantics
43

44. Topics & Queues
44

45. Durable or Ephemeral
45

46. Messaging allows separation of
concerns at the API level
46

47. Event Sourcing
Command Query Responsibility
Segregation (CQRS)
https://martinfowler.com/eaaDev/EventSourcing.html
https://martinfowler.com/bliki/CQRS.html
47

48. RSocket
48

49. Reactive Streams semantics on
protocol level
49

50. Message-driven
Asynchronous
50

51. Fire-and-Forget
Request/Response
Request/Stream
Channel
51

52. Flow Control
Backpressure
Leasing
52

53. Binary
53

54. TCP
WebSockets
Aeron
Upcoming: HTTP/3 (QUIC)
54

55. Gateways
55

56. Discoverability
56

57. Changing topology
57

58. Service Registration and Discovery
Service A
Service Registry
Service A
Service A
1. Register
Service B
2. Query for service A instances
3. Connect
58

59. Spring Cloud Gateway
59

60. Spring Cloud Gateway
Spring Cloud
Gateway
Service 1
Service 2
Service 3
Service 4
Mobile App
Web App
60

61. Spring Cloud Gateway
Load Balancing
Fault Tolerance
Rate Limiting
Security
61

62. RSocket Broker
62

63. RSocket Broker
Load Balancing
Fault Tolerance
Security
Service Discovery
63

64. RSocket Broker
RSocket
Broker
Service 1
Service 3
Service 2
Service 3
RSocket
Broker
RSocket
Broker
Service 1
Service 2
64

65. RSocket 💖 HTTP
65

66. RSocketHttpBridge
66

67. http POST
host:port/serviceId/rsocketEndpointId
< valid.json
67

68. POST
Service ID and RSocket endpoint from URI
byte[]
Tags passed as headers
Interaction mode from URI or default
WellKnownKey
68

69. Architecture
69

70. Greenfield
70

71. Allows builders to choose
the right tool for the job
71

72. Constraints are:
budget, personnel, time to market,
functional requirements.
72

73. Freedom of choice
73

74. Legacy/Heritage
74

75. Modernising architecture by areas/
components
75

76. Legacy Service + RSocket ecosystem
Legacy HTTP
Service
RSocket
Broker
RSocket Service
RSocket Service
RSocket Service
RSocket Service
76

77. Legacy Service + RSocket ecosystem
Legacy HTTP
Service
RSocket
Broker
RSocket Service
RSocket Service
RSocket Service
RSocket Service
HTTP RSocket
Bridge
77

78. Demo
78

79. Demo Flow
HTTP Loan Service RSocket Broker
RSocket
Verification
Service
Gateway
HTTP RSocket
Bridge
Verification Request
Verification Response
79

80. Resources
● https://github.com/OlgaMaciaszek/spring-one-2021-rsocket-http-sample
● https://github.com/rsocket-routing/rsocket-routing-broker
● https://github.com/spring-projects-experimental/spring-native
● https://spring.io/projects/spring-cloud-function
● https://spring.io/projects/spring-cloud-contract
● https://spring.io/projects/spring-cloud-gateway
● https://rsocket.io/
80

81. Thank you
@olga_maciaszek
@spencerbgibb
© 2020 Spring. A VMware-backed project.
81