The document summarizes a presentation given on microservices architecture using Spring Cloud and Netflix OSS. It defines microservices as structuring an application as loosely coupled services organized by business capabilities. Key benefits include faster deployments, independent scalability, and greater resiliency. Challenges include overall complexity in distributed systems with latency, faults, and operational overhead. The presentation demonstrates how to create microservices using Spring Boot and leverage Netflix OSS libraries for service discovery, load balancing, and resiliency patterns. Best practices emphasized testing services for resiliency under various error conditions.

1. SPRING CLOUD
MICROSERVICES WITH
NETFLIX OSS
BOSTON JAVA MEETUP, CAMBRIDGE, MA
NOVEMBER 12, 2019
Miya W Longwe
Founder of Ezcloud Technologis Inc,
mlongwe@gmail.com

2. @mlongwe
PRESENTATION GOAL
Define the Microservice Architecture
Explain what that means and why it
matters
Review implementation using Spring
Cloud and Neflix OSS

3. @mlongwe
ABOUT MIYA

4. @mlongwe
ABOUT MIYA
Consultant and developer
focusing on modern
application architectures
including microservices
Technology evangelist

5. AGENDA
A brief refresher on software architecture
The journey monolith to microservices
Microservices != silver bullet
Applying the microservice pattern language
@mlongwe

6. ABOUT SOFTWARE
ARCHITECTURE
“The software architecture of a computing system is the
set of structures needed to reason about the system,
which comprise software elements, relations among
them, and properties of both.”
Documenting Software Architectures, Bass et al

7. Architecture
=
(elements, relations, properties)
@mlongwe

8. @crichardson
The monolithic architecture
is an architectural style
that structures the application
as a single executable
component
Implementation view

9. @crichardson
Tomcat/App. Server
Traditional: Monolithic
architecture
Browser/
Client
WAR/EAR
MySQL
Database
Review
Management
Catalog
Management
Recommendation
Management
StoreFrontUI
Order
Management
HTML
REST/JSON
Logical view
Implementation view

10. But successful applications keep
growing….
Development
Team
Application
@crichardson

11. … and growing
Development
Team A
ApplicationDevelopment
Team B
Development
Team C
@longwe

12. Technology stack becomes
increasingly obsolete
BUT
Arewrite is not feasible
@crichardson

13. TIPPING POINT
& &
Organizational Growth Diverse Functionality Bottleneck in
Monolithic stack

14. MONOLITHIC APPS – FAILURE & AVAILABILITY

15. MicroServices
You Think??

16. MONOLITHIC APP (VARIOUS COMPONENTS LINKED TOGETHER)
Comparing Monolithic to Micro-Services

17. The microservice architecture
is an architectural style
that structures an
application as a
set of loosely coupled,
services organized around
business capabilities

18. MICRO-SERVICES – SEPARATE SINGLE PURPOSE SERVICES

19. Monolithic Architecture (Revisiting)
Load Balancer
Monolithic App
Account
Component
Catalog
Component
Recommendation
Component
Customer Service
Component
Database

20. Micro-services Architecture
Load Balancer
Account Service Catalog
Service
Recommendation
Service
Customer Service
Service
Catalog DB
API Gateway
Customer DB

21. Concept -> Service Dependency Graph
Your
App/Service
Service X
Service Y
Service Z
Service L
Service M

22. CHARACTERISTICS
 Many smaller (fine grained), clearly scoped services
 Single Responsibility Principle
 Domain Driven Development
 Bounded Context
 Independently Managed
 Clear ownership for each service
 Typically need/adopt the “DevOps” model
Attribution: Adrian Cockroft, Martin Fowler …

23. WHY?
 Faster and simpler deployments and rollbacks
 Independent Speed of Delivery (by different teams)
 Right framework/tool/language for each domain
 Recommendation component using Python?, Catalog Service in Java ..
 Greater Resiliency
 Fault Isolation
 Better Availability
 If architected right 

24. Micro-Services
- Challenges

25. CHALLENGES
Can lead to chaos if not designed right …

26. OVERALL COMPLEXITY
• Distributed Systems are inherently Complex
• Latency, Fault Tolerance, Retry storms ..
• Operational Overhead
• TIP: Embrace DevOps Model

27. CREATING MICRO-SERVICES

28. SPRING CLOUD

29. CREATING MICRO-SERVICES– SPRING BOOT

30. SERVICE ARCHITECTURE
SPRING BOOT & SPRING CLOUD NETFLIX OSS

31. SERVICE DISCOVERY
• 100s of Micro-Services
• Need a Service Metadata Registry (Discovery Service)
Account Service Catalog
Service
Recommendation
Service
Customer Service
Service
X
Service Y
Service
Z
Service
Registry
Service
(e.g. Netflix Eureka)

32. Central (Proxy) Loadbalancer
Account Service Load
Balancer
Account Service 1
Recommendation
Service 1
Customer Service
Service 1
API Gateway
Account Service N
Recommendation
Service N
Customer Service
Service N
Customer Service Load
Balancer
Reco Service
Load Balancer

33. Resiliency/Availability

34. NO SILVER BULLETS
http://en.wikipedia.org/wiki/Fred_Brooks
@crichardson

35. * Benjamin Franklin

36. * Inspired by Benjamin Franklin
three

37. CHALLENGES - SUMMARY
• Service Discovery
• Operational Overhead (100s of services; DevOps model absolutely required)
• Distributed Systems are inherently Complex
• N/W Latency, Fault Tolerance, Serialization overhead ..
• Service Interface Versioning, Mismatches?
• Testing (Need the entire ecosystem to test)
• Fan out of Requests -> Increases n/w traffic

38. Best Practices/Tips

39. Best Practices contd..
• Test Services for Resiliency
• Latency/Error tests (via Simian Army)
• Dependency Service Unavailability
• Network Errors

40. DEMO

41. Takeaways

42. Takeaways
• Monolithic apps – good for small organizations
• MicroServices – have its challenges, but the benefits are many
• Consider adopting when your organization scales
• Leverage Best Practices
• An Elastic Cloud provides the ideal environment (Auto Scaling etc.)
• NetflixOSS has many libraries/samples to aid you

43. Questions?