The all functional programming world, Docker, Clever Cloud, micro service architecture, logs append only DB… All of this rely on the immutability at some point: infrastructure immutability, data immutability, append only. This is the way we now build some of the best scalable applications and infrastructure. The talk is made to understand why Immutability rules the scalability and why it’s important.

1. IMMUTABILITY, FROM
CODE TO
INFRASTRUCTURE,
THE WAY OF
SCALABILITY
@WAXZCE
QUENTIN ADAM AT PARIS OPEN SOURCE SUMMIT

2. Quentin ADAM from the Clever Cloud
@waxzce on twitter – github- soundcloud – instagram ….
WHO AM I ?

3. MY DAY TO DAY WORK :
CLEVER CLOUD, MAKE YOUR
APP RUN ALL THE TIME

4. And learn a lot of things about your code, apps, and good/bad design…
KEEP YOUR APPS ONLINE. MADE WITH
NODE.JS, SCALA, JAVA, RUBY, PHP,
PYTHON, GO…

5. AND LEARN A LOT OF THINGS ABOUT
YOUR CODE, APPS, AND GOOD/BAD
DESIGN…

6. WHEN YOU
NEED TO
SCALE
THERE ARE 2 WAYS

7. GROWING AND GROWING
UNTIL YOU EXPLODE OR
BECOME WEIRD

8. OR SPLIT THE WORK AND
MAKE YOUR SOFTWARE
WORK AS A TEAM

9. Build an army of fat app
YOU CAN DO BOTH

10. SO WE NEED TO BE ABLE
TO DISPATCH THE WORK
SCALE OUT
• Many workers
doing the same
thing
• No SPOF
• Growing is more
easy
• Introduce best
practice
SCALE UP
• 1 Fat instance
• 1 Fat application
• SPOF (single point
of failure)
• Hard to maintain
• Always has a limit
• Short term
meaning

11. CLUSTER &
MANY
CORES IN
CPU

12. ACCESS TO THE DATA IN A MUTABLE
STATE

13. MAKE EVERYBODY WORKS

14. CONSIDER
VARIABLE OR
VM AS A
“DATA BOX”

15. POSSIBLE STATE IN A
MUTABLE STATE
reading
value
updating
value at a
particular
version
nothing
lock by a
editor
History …

16. POSSIBLE STATE IN
AN IMMUTABLE STATE
defined
undefined
Very simple to predicate

17. FIX THE DATA
IN A
IMMUTABLE
STATE

18. LET’S TALK ABOUT
INFRASTRUCTURE

19. HOSTING
Backup Updates Certification
Agreement Process Provisioning
Security
Hardware
maintenance

20. CREATE HISTORY

21. DOCUMENTATION

22. SPECIFIC

23. TAYLOR MADE

24. NOT ABLE TO SCALE

25. IMMUTABLE
INFRASTRUCTURE

26. FULLY AUTOMATED HOSTING FACTORY

27. PRODUCTION HAS TO BE PERFECT

28. PEOPLE ARE NOT PERFECT

29. PEOPLE HAVE NOTHING TO DO ON
PRODUCTION STUFF

30. ULTRON

31. AT CLEVER CLOUD SSH CONNECTION
IS A RED ALERT

32. AN INSTANCE IS DEAD OR ALIVE AND
THAT’S ALL

33. APP FAIL ?
REDEPLOY
NEW
INSTANCE

34. OPERATION
SYSTEM
UPDATE ?
REDEPLOY
NEW
INSTANCE

35. OPERATION
SYSTEM
UPDATE ?
REDEPLOY
NEW
INSTANCE

36. Picking one instance or another doesn’t matter
STATELESSNESS IS THE KEY

37. SPLIT PROCESS AND
STORAGE
Storage
• Databases
• Files
• Sessions
• Events
• …
Code
• Can be replicated
• Stateless
• Process

38. BECAUSE YOU WILL NOT RELY
ON A SERVER ANYMORE

39. CREATE A FACTORY OF INSTANCE

40. IMMUTABILITY : NEVER DELETE,
ALWAYS CLONE, BE STATELESS

41. I’m on twitter : @waxzce
quentin.adam@clever-cloud.com
THANK YOU !
ANY QUESTIONS ?