Presentation from XP Days Ukraine (December, 2011) about establishing continuous delivery process in development team

1. CONTINUOUS DELIVERY
Mikalai Alimenkou
http://xpinjection.com
17.12.2011

2. Background
• Java Technical Lead/Scrum Master at Zoral
Labs
• 7+ years in software development
• 5+ years of working by Agile
methodologies
• Expert in Agile engineering practices
• Founder and coach at XP Injection
(http://xpinjection.com)
• Organizer of Selenium Camp, JEEConf and
XP Days Ukraine conferences

3. Every tool or practice should solve particular problems
WHY CONTINUOUS DELIVERY?

4. What changed in business?
It is faster now!
• Что изменилось в бизнесе? Он стал
быстрее.

5. How long?

6. Still afraid of releases?

7. Your typical release

9. !!!

10. Kanban promotes
continuous flow

11. XP style – if
it hurts, do it
more often

12. “How long would it take your organization to
deploy a change that involves just one single line
of code?
Do you do this on a repeatable reliable basis?”
- Mary and Tom Poppendieck

13. Continuous Delivery
Keeping systems production-
ready throughout
development, so that they can
be released to users at any time

14. ”Continuous delivery is about putting the release
schedule in the hands of the business, not in the hands
of IT.
Implementing continuous delivery means making sure
your software is always production ready throughout
its entire lifecycle – that any build could potentially be
released to users at the touch of a button using a fully
automated process in a matter of seconds or minutes.”
- Jez Humble

15. Nobody tell you it is easy, but many people practice it
REQUIRED STEPS FOR SUCCESS

16. 1. Select version Release should
2. Select environment be simple
3. Push the button

17. WTF?!?
What about QA?
Risk Management?
Team Policies?

18. Automate
everything!
Upgrade
Tests
Build
Deployment

19. Stable releasable trunk

20. How is it possible?
Small features
Slicing development
Don’t show UI
Feature flags

21. Global Continuous
Integration

22. TDD at all levels
ATDD TDD
Customer’s Tests Programmers’ Tests
Acceptance Fixtures Production Unit Integration
Tests Code Tests Tests

23. Detailed static code analysis

24. 1. Plan
2. Prepare
3. Test
Always think
about rollback

25. Deployment
Load balancer sample
X
App Server
X
DB Server

26. Deployment
Load balancer sample
X X 1. Start new App Server
2. Use slave DB
App Server App Server
X X
DB Server DB Server

27. Deployment
Load balancer sample
X X 1. Start new App Server
2. Use slave DB
3. Deploy in read only mode
App Server App Server
4. Switch load balancer
X X
DB Server DB Server

28. Deployment
Load balancer sample
Y X 1. Start new App Server
2. Use slave DB
3. Deploy in read only mode
App Server App Server
4. Switch load balancer
5. Update master DB
6. Deploy new code
Y X
DB Server DB Server

29. Deployment
Load balancer sample
Y X 1. Start new App Server
2. Use slave DB
3. Deploy in read only mode
App Server App Server
4. Switch load balancer
5. Update master DB
6. Deploy new code
7. Switch load balancer
Y X
DB Server DB Server

30. Deployment
Load balancer sample
Y 1. Start new App Server
2. Use slave DB
3. Deploy in read only mode
App Server 4. Switch load balancer
5. Update master DB
6. Deploy new code
7. Switch load balancer
Y Y 8. Release old App Server
9. Synchronize slave DB
DB Server DB Server

31. Don’t forget about…
Monitoring Smoke testing
5 whys technique Retrospective

32. How to start?
Start with walking skeleton Automate step by step
Reduce deploy batch size Reduce deployment cycle

33. Visualize path of your code from developers to end users
BUILD PIPELINES

34. Performance
Dev Testing
Testing
Staging Demo UAT
Production
Different
environments
on code path

35. Build Pipeline sample

37. Build pipeline sequence

38. Jenkins Build
Pipeline Plugin

39. TeamCity
Build Chain

40. Cruise Pipelines

41. Do nothing before benefits are not clear for you
CONTINUOUS DELIVERY BENEFITS

42. Reduce errors in manual
repeatable tasks

43. Fail early with deployment

44. Small changes
reduce risks

45. Short feedback cycle

46. Everybody can deploy to
production

47. Before After
Dev Commit
Monitor Test
Release QA
Deploy
• 2 week release cycles
• code freeze • multiple releases a day
• big events • non-events
• large code changes • small number of changes

48. Books to read

49. @xpinjection
http://xpinjection.com
mikalai.alimenkou@xpinjection.com