The document presents an overview of microservice architecture as implemented by Ctrip, discussing the advantages of system decoupling for deployability and scalability and the challenges of monolithic architectures. It highlights the migration process from a monolithic mobile backend to microservices, focusing on best practices, lessons learned, and the infrastructure required for successful implementation. The author emphasizes the importance of architecture design principles and acknowledges the operational overhead and complexities associated with microservices.

1. MicroService Architecture
@Ctrip
William Yang(杨波)
Dev Manager & Architect
@Ctrip.com

2. Problem Domain
• System decoupling for deployability and
scalability
• Evolutionary architecture and adaptive
organization
• Mobile Backend Architecture

3. Agenda
• The curse of the monolith
• Case study – decomposing Ctrip mobile
backend into microservice
• Microservice best practice
• What we have learned

4. Initial Ctrip Mobile Backend
Architecture
Monolithic Mobile Service
SBU A SBU B SBU C SBU D
SOA/ESB

5. Pros & Cons
• At the beginning …
simple to develop, test, deploy and scale
• Later …
huge, complex, monolithic mobile service

6. The Curse of the Monolith
• Bloated codebase
• Communication and coordination cost
• Obstacle for frequent deployments
• Little resilience to failure
• Commitment to a single technology stack
• Hindering innovation

7. MicroService Architecture Style
• Decomposing a single app as a suite of services
• Communicating with lightweight mechanism
• Built around business capabilities
• Independently deployable
• Minimum of centralized management
• May be written in different programming
languages and use different storages
http://martinfowler.com/articles/microservices.html

8. Who has Migrated to MicroService
http://microservices.io/patterns/microservices.html

9. New Mobile Backend Arch @Ctrip

10. Key MicroService Infrastructure
• Service
– Service framework, gateway, registry
• Monitoring
– Logging, tracing, metrics
• Deployment
– TEST/UAT/PROD environments
– CI/CD
• Push common concerns to technical
infrastructure

11. MicroService Framework @Ctrip

12. Service Metrics Monitoring

13. MicroService Availability
• Assume a monolithic service with 99.99%
availability, what if you have ~30 microservices
each with 99.99% availability??
• Combined effective availability
== 2 HOURS of downtime per month
== 99.7% uptime!!

14. Service Dependency

15. Single Dependency Delay

16. Cascading Failure at Peak Hour

17. Basics of Service Fault Tolerance
• Circuit Breaker(Fuse Blow)
• Isolation
• Rate Limiting
• Fallback

18. Hystrix Circuit Breaker
http://github.com/netflix/hystrix

19. Ctrip Gateway Hystrix Dashboard

20. MicroService Gateway

21. Gateway Filtering Mechanism
“pre” filters “routing” filter(s) “post” filters
Origin Server
“error” filters
HTTP Request
Http Request Http Response
https://github.com/Netflix/zuul

22. Filter Management

23. Advanced Usage of Gateway
• Surgical debugging
• Stress testing
• Canary testing
• Service migration
• Load shedding
• Active/Active traffic management

24. Migration to MicroService
Achievement @Ctrip
• System decoupled and domain ownership
clarified
• Business innovation speed accelerated
• Overall system reliability improved
• Decentralized architecture w/o SPOF
• Develop, test, deploy and scale independently
• Evolutionary architecture

25. What We Have Learned One
• Smooth Migration
– Give buffer to user for migration

26. What We Have Learned Two
• Follow Architecture & Design Best Practice
– Single responsibility & separation of concerns
– Dependency inversion
– Dependency isolation
– Rate limiting & circuit breaker
– Dynamic deployable & re-configurable
• Top-Level Design
– Fit service into infra, not fit infra into service

27. What We Have Learned Three
• Conway’s Law
– “Any organization that design a system(defined
broadly) will produce a design whose structure is a
copy of the organization’s communication
structure” – Melvin Conway, 1968
– “Those system then constrain the options for
organizational change” – Dan North

28. Caveat
• MicroService is not a Free Lunch
– Significant operations overhead
– Substantial DevOps skills required
– Implicit interface
– Duplication of effort
– Distributed system complexity
– Testability challenges
http://highscalability.com/blog/2014/4/8/microservices-not-a-free-lunch.html

29. Future – Soft Load Balancing

30. Future – Cross Data Centers

31. About Me
• William Yang(杨波)
• Dev Manager & Architect @Ctrip Middleware
Team @Shanghai
We are
hiring!

32. 谢谢