The document outlines 11 design principles for developing applications in a DevOps manner: manageability, resilience, and transparency. Manageability principles include one-click deployment, configuration management, and backup strategies. Resilience principles involve bulkheads, redundancy, loose coupling, and fallbacks. Transparency principles cover monitoring and logging. The design principles aim to satisfy an operations administrator's needs for peace of mind, easy use, visibility into problems, and guidance on resolutions.

1. ROME 11-12 april 2014ROME 11-12 april 2014
DevOps for Developers
or how to put a smile on your admin’s face
uwe.friedrichsen@codecentric.de - codecentric AG
Uwe Friedrichsen

2. ROME 11-12 april 2014 - Speaker’s name
All slides of this presentation are available under a
Creative Commons licence
“http://creativecommons.org/licenses/by-nc-sa/3.0/”

3. @ufried
Uwe Friedrichsen | uwe.friedrichsen@codecentric.de | http://slideshare.net/ufried | http://ufried.tumblr.com

4. DevOps

5. DevOps
DevQA
DevPO
DevRE
DevPM
DevDev
DevDevPO
DevDevDev

6. It‘s all about production!

7. Operations
Developers Point of View

8. Admin
Developers Point of View

9. Admin
Closer to Reality Point of View

10. Top 5 Needs of an Admin
1. Give me my peace and quiet!
2. Don‘t make me think!
3. Let me see that everything is fine!
4. Show me the problem – now!
5. Tell me what to do!

11. Top 5 Needs of an Admin (translated)
1. Give me my peace and quiet!
(The application should just run smoothly)
2. Don‘t make me think!
(Rollout, setup and operation of the application should be easy)
3. Let me see that everything is fine!
(The application should show its state)
4. Show me the problem – now!
(The application should provide concise error messages and enable easy root cause drilldown)
5. Tell me what to do!
(The application should be documented properly – including error handling instructions)

12. Top 3 Dev Challenges
1. Manageability
2. Resilience
3. Transparency
4. Documentation

13. 11 Design Principles
for DevOps-ready Applications
• Manageability (4)
• Resilience (5)
• Transparency (2)

14. Manageability

15. Deployment
(Manageability)

16. • One-click deployment
• Preserve settings
• Provide rollbacks (or roll-forward)

17. Configuration
(Manageability)

18. • Avoid multiple configuration procedures
• Define default value handling
• Organize change traceability
• Notification about new parameters

19. Configuration Parameter Types
(Manageability)

20. • Context-related parameters
Do not stage – managed by stage admin
• Application-related parameters
Must be staged – managed by application admin
• Business-related parameters
Must be staged – managed by business admin

21. Backup
(Manageability)

22. • Think about backup purpose
• Define backup strategy
• Provide tooling

23. Resilience

24. Bulkheads
(Resilience)

25. • Divide system in failure units
• Isolate failure units
• Define fallback strategy

26. Redundancy
(Resilience)

27. • Elaborate use case
Minimize MTTR / scale transactions / handle response errors / …
• Define routing & balancing strategy
Round robin / master-slave / fan-out & quickest one wins / …
• Consider admin involvement
Automatic vs. manual / notification – monitoring / …

28. Loose Coupling
(Resilience)

29. • Isolate failure units (complements bulkheads)
• Go asynchronous wherever possible
• Use timeouts & circuit breakers
• Make actions idempotent

30. Fallbacks
(Resilience)

31. • What will you do if a request fails?
• Consider failure handling from the very beginning
• Supplement with general failure handling strategies

32. Scalability
(Resilience)

33. • Define scaling strategy
• Think full stack
• Apply D-I-D rule
• Design for elasticity

34. Transparency

35. Monitoring
(Transparency)

36. • Think about required metrics
• Design hook or event mechanism
• Plan for changing metrics
• Consider event sourcing

37. Logging
(Transparency)

38. • Consider log message structure
All required information / human readable / machine readable
• Define logging policy
Debug and less: developers perspective / Info and more: operations perspective

39. 11 Design Principles
• Manageability
• Deployment
• Configuration
• Configuration Parameter Types
• Backup
• Resilience
• Bulkheads
• Redundancy
• Loose Coupling
• Fallbacks
• Scalability
• Transparency
• Monitoring
• Logging

40. Wrap-up
• It’s all about production!
• Know the needs of an admin
• Face the challenges for a developer
• Apply the design principles
… and then you‘re ready for DevOps

41. @ufried
Uwe Friedrichsen | uwe.friedrichsen@codecentric.de | http://slideshare.net/ufried | http://ufried.tumblr.com