1. Introduction to
Spring Cloud
Slack: #session-introduction-to-spring-cloud
Olga Maciaszek-Sharma @olga_maciaszek
Spencer Gibb @spencerbgibb

2. Safe Harbor Statement
The following is intended to outline the general direction of VMware's offerings. It is intended for
information purposes only and may not be incorporated into any contract. Any information regarding
pre-release of VMware offerings, future updates or other planned modifications is subject to ongoing
evaluation by VMware and is subject to change. This information is provided without warranty or any kind,
express or implied, and is not a commitment to deliver any material, code, or functionality, and should not
be relied upon in making purchasing decisions regarding VMware's offerings. These purchasing decisions
should only be based on features currently available. The development, release, and timing of any features
or functionality described for VMware's offerings in this presentation remain at the sole discretion of
VMware. VMware has no obligation to update forward looking information in this presentation.

3. Agenda
• Cloud Native
• Sample Architecture
• Spring Cloud Components
• Revisit Sample Architecture
• Demo
3


4. Cloud Native
• Distributed
• Scalable
• Resilient
• Automated
• Organizational (Conway’s Law)
• Replaceable
4


5. Fallacies of Distributed Computing
• The network is reliable.
• Latency is zero.
• Bandwidth is infinite.
• The network is secure.
• Topology doesn't change.
• There is one administrator.
• Transport cost is zero.
• The network is homogeneous.
https://web.archive.org/web/20071223073932/http://java.sys-con.com/read/38665.htm 5


6. 12 Factor Apps https://12factor.net
1.Code in VCS
2.Dependencies
3.Config in environment
4.Backing Services
5.Build, release, run
6.Process
6

7.Port binding
8.Concurrency
9.Disposability
10.Dev/prod parity
11.Logs
12.Admin processes
See also the 1 Factor App and 15 Factor Apps

7. User Service
Sample Architecture
API Gateway Metrics
Service
Discovery
Fraud
Verifier
Configuration
Card Application
Service

8. Distributed Configuration
Service
A
Config Server
Service
B

9. Spring Cloud Config Server
● Pluggable
○ Git
○ Vault
○ Credhub
○ JDBC
○ IaaS resource (S3, etc…)
● Retry
● Spring Boot compatible client
9

10. Spring Cloud Consul Config
● Bring your own Consul
● Uses key-value store
● Can be on value per key or a file per key
● Can be auto-refreshed
● Spring Boot compatible client
1
0

11. Others
● Spring Cloud Vault
● Spring Cloud Zookeeper Config
● Direct to IaaS
○ Spring Cloud Alibaba
○ Spring Cloud AWS
○ Spring Cloud Azure
○ Spring Cloud GCP
● Platform
○ K8s config maps
1
1

12. Service
A
Service
A
Service Registration and Discovery
Service
A
Service
Registry
Service
B
1. Registers 2. Query for Service A instances
3. Connect

13. Netflix Eureka
● Provided by Spring Cloud Netflix
● Highly Available
● Eventually Consistent
● Netflix uses Spring Cloud Netflix!
http://techblog.netflix.com/2012/09/eureka.html
1
3

14. Consul by Hashicorp
● Integration by Spring Cloud Consul
● Bring your own Consul Servers
● Can be strongly consistent
● Uses Services API
● Supports consul health checks
● Spring Boot compatible client
1
4

15. Others
● Spring Cloud Zookeeper Discovery
● Spring Cloud Alibaba (Nacos)
1
5

16. Client Side Load-balancer
Service
A
Service
A
Service
A
Service
Registry
Service
B
1. Query service A
instances 2. Select the service A instance to
send the request to
Service
A
Service
A
Service
A

17. Spring Cloud LoadBalancer
● Replaces Netflix Ribbon
● Pluggable algorithm
● Reactive support
● Extensible configuration
1
7

18. Failure Mitigation

19. Spring Cloud Circuit Breaker
● Protects from cascading failures
● Fallback
● Pluggable
○ Resilience4j
○ Spring Retry
○ Spring Cloud Alibaba (Sentinel)
● Pluggable algorithm
● Reactive support
1
9
Open
Closed
Half
Open
Failure
threshold
exceeded
Success
Timeout
Reset
Failure

20. Retry
● Retry failed requests
● Spring Retry
● Project Reactor
● Resilience4j
2
0

21. Distributed Tracing
Browser
API Gateway
User
Service
Mobile
App
Cart
Service
Inventory
Service
Inventory
DB
User
DB

22. Spring Cloud Sleuth
● Trouble-shooting across a distributed system
● Instruments for tracing
○ Spring Framework
○ Spring Boot
○ Spring Cloud
2
2

23. API Gateway
Browser
API Gateway
User
Service
Mobile
App
Cart
Service

24. Spring Cloud Gateway
● API Gateway
● Spring Boot App
● Focus on developer experience and customization
● Supports Spring Cloud
○ Configuration
○ Service Discovery
○ LoadBalancer
○ Retry/Circuit Breaker
○ Rate Limiting
○ Sleuth
2
4

25. User Service
(SC Circuit
Breaker)
Sample Architecture with Spring Cloud
Spring Cloud
Gateway
(SC CircuitBreaker,
Retry)
Metrics
Eureka
Service
Discovery
Fraud
Verifier
Spring Cloud
Config Server
Card Application
Service
(SC LoadBalancer)

26. Demo

27. What we did not talk about.

28. More to Spring Cloud
● Spring Cloud Bus
● Spring Cloud OpenFeign
● Spring Cloud Contract
● Spring Cloud Function
● Spring Cloud Stream
● Spring Cloud Task
● Spring Cloud Data Flow
● ...
2
8

29. Stay Connected.
Slack: #session-introduction-to-spring-cloud
https://github.com/spring-cloud-samples/spring-cloud-intro-demo
https://github.com/spring-cloud
https://spring.io/projects/spring-cloud
Olga Maciaszek-Sharma @olga_maciaszek
Spencer Gibb @spencerbgibb
#springone@s1p