- Microservices are small, independent services that each perform a single function. They communicate through well-defined interfaces using protocols like HTTP. This allows for independent development and scaling of each service. - The advantages of microservices include increased flexibility, scalability, and allowing a system to evolve more easily. However, they also introduce more complex infrastructure requirements and can result in fragmented data. - The presentation provides examples of how microservices can be implemented incrementally by starting with high-level services and extracting smaller ones over time as needed. It also emphasizes the importance of testing, automation, and other DevOps practices for managing microservices architectures.

1. Adventures
with
micro-Services
Mohit Thatte (@mohitthatte)
Anand Agrawal (@anand_agrawal)
ThoughtWorks Inc.

2. Enough about us.
What’s in it for you?

3. What?
Why?
How?
When?

4. What are micro services?services?micro

5. What are micro services?
services?
micro

6. What are micro services?
A real thing that does some thing!
services?
micro

7. What are micro services?
A real thing that does some thing!Implementation Contract
services?
micro

8. What are micro services?
small independent composable
services
that do one thing well

9. Unix philosophy
Write programs that do one thing well.
Write programs that work together.
cat | grep | sed | awk | ...
HTTP is the new pipe!

10. Single responsibility
Low coupling, high cohesion
Small, well defined interfaces
Object Oriented philosophy

11. use micro services?Why we

12. Once upon a time...

13. lots of legacy, no reuse
not flexible, high cost of change
no one knows how it works
concentrated complexity
90 year old business

14. lots of legacy, no reuse
not flexible, high cost of change
no one knows how it works
concentrated complexity
independent small that do one thingcomposable
90 year old business

15. “A 100k loc app is
just 100 1k loc apps
waiting to happen”
- Jeff Bay

16. Adventure so far
25 VM’s in production
10 micro-services
one click deployment
60+ VM’s across environments

17. µService
DB
µService
DB
µService
DB
µService
DB

18. How did we start?

19. Solve small, valuable problems

20. Start with high level services

21. When a service starts doing too much,
extract a smaller one

22. Orders PaymentsCustomers
Catalog
(Games)

23. Orders PaymentsCustomers
Legacy
Catalog
(Games)

24. Orders PaymentsCustomers
Legacy
Order
Processing
Catalog
(Games)

25. Orders PaymentsCustomers
Legacy Results
Order
Processing
Catalog
(Games)

26. Looks like plain old services,
what makes them ‘micro’?

27. single responsibility
1 service = 1 ‘resource’
(maybe 2!)

28. I can haz code of conduct?

29. respect service boundaries
focus on contracts
avoid coupling
extract cross cutting concerns

30. Orders PaymentsCustomers
Communications
Legacy Results
Order
Processing
Scheduled
Jobs
Error
reporting
Catalog
(Games)

31. So many repos,
how do you stay productive?

32. automate, automate, automate...

33. DevOps #ftw
15 minute dev box setup
spin up a new service in minutes*
Vagrant + Puppet = AWESOME!

34. feature toggles over branches

35. client gems

36. Is that all captain?

37. add health checks + circuit breaker

38. logging
can you trace a request through?

39. Avoid / Defer
versioning services
manual tinkering on VM’s

40. How do I make a change
and still stay sane?

41. Test It!

42. Unit Tests

43. Contract Tests
is my service doing what it should?
out of container
strictly black box

44. Integration Tests
are all my services playing nicely together?
testing distributed effects
testing async actions

45. Continuous Integration
Integration
Tests
UAT Performance
Production
Service
Tests

46. Ok, so you tested it, now
release it!

47. Step 1: Set up ze VM’s

48. Puppet Solo + SSH in a loop
Puppet goes through CI just like app code
Our ideal : ImmutableServer
deploy all or nothing

49. Step 2: Deploy ze code

50. Continuous Integration
Integration
Tests
UAT Performance
Production
Service
Tests

51. CI + DevOps
enables
single-click deployment
so easy, our product owner does it!
it just works™
3 mins to production (~25 servers)

52. “we’re effectively pushing the
complexity from the application
into the infrastructure...”
- James Lewis

53. When to use micro-services?

54. Tradeoffs
benefit cost
small units of reuse/maintain complex infrastructure
grow independently learning curve
scale independently network overhead
independent DB fragmented data
Polyglot

55. Thanks!

56. Questions?