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 SNOWCAMP

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

3. MY DAY TO DAY WORK :
CLEVER CLOUD, THE IT
AUTOMATION COMPANY

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. SCALE OUT

12. CREATE PARALLEL
WORK UNIT

13. CPU:
MANY CORES

14. APPS:
CLUSTERING

15. TEAM:
MICROSERVICE

16. SYNCHRONIZE
ACCESS TO
THE DATA BY
THE ACTORS

17. DATA MANAGEMENT
IS MANDATORY

18. ACCESS TO THE DATA IN A MUTABLE
STATE

19. MAKE EVERYBODY WORKS

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

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

22. IS THE
DATA
READABLE?

23. FIX STATE OF
THE DATA TO
ENSURE
ACCESSIBILITY

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

25. FIX THE DATA
IN A
IMMUTABLE
STATE

26. AVOID HISTORY

27. EXAMPLE ON COLLECTIONS
MANAGEMENT

28. EPHEMERAL
COPY

29. DETERMINED
SCENARIO

30. RAM & SPACE

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

32. CONSIDER MORE
THINGS AS DATA
• User account
• Users data
• Files
• Sessions
• Events

33. DATA QUALIFICATION

34. Data
Process
data
Data
pipeline

35. IMMUTABILITY
FOR YOUR
CODE

36. IMMUTABILITY
AS A PATTERN

37. LET’S TALK ABOUT
INFRASTRUCTURE

38. 40 times in 5 years price drop of AWS
SERVERS COSTS ARE GOING DOWN

39. Google I/O 2015
“RACE TO ZERO”
I.E THE SERVER IS FREE

40. In fact, all you have is…
COOL.
YOU HAVE A SERVER.

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

42. CREATE HISTORY

43. DOCUMENTATION

44. SPECIFIC

45. TAYLOR MADE

46. NOT ABLE TO SCALE

47. DO NOT
CREATE
HISTORY

48. EPHEMERAL
SERVERS?

49. IMMUTABLE
INFRASTRUCTURE

50. THERE IS ONE PROCESS:
BUILD

51. THEN, REGISTER

52. AND LIVE WITHOUT DATA

53. AND DIE WHEN MORE
UPDATED VERSION IS THERE

54. TRASH OLD VERSION

55. HOW TO MANAGE
DATA?

56. VM, docker, kubernetes, puppet, ansible, vmware… This is not the problem
TECHNOLOGIES?

57. FULLY AUTOMATED HOSTING FACTORY

58. PRODUCTION HAS TO BE PERFECT

59. PEOPLE ARE NOT PERFECT

60. PEOPLE HAVE NOTHING TO DO ON
PRODUCTION STUFF

61. ULTRON

62. AT CLEVER CLOUD SSH CONNECTION
IS A RED ALERT

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

64. APP FAIL ?
REDEPLOY
NEW
INSTANCE

65. OPERATION
SYSTEM
UPDATE ?
REDEPLOY
NEW
INSTANCE

66. OPERATION
SYSTEM
UPDATE ?
REDEPLOY
NEW
INSTANCE

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

68. BECAUSE YOU WILL NOT RELY
ON A SERVER ANYMORE

69. CREATE A FACTORY OF INSTANCE

70. BE CONSISTENT AND PREDICTABLE

71. NO MORE OLYMPIC CONTEST ON
UPTIME

72. IMMUTABILITY

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

74. AND LOG ALL TO GET AN EVENT
STREAM ;-)

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