1. Zero to 1 Billion Records
Kiril Savino @holacrat

2. 2
GC.com/about/product-team

3. 3
• have a sense of humor
• know what use cases work best
• remember that databases are hard
• don’t understate the difficulty in scaling up

4. 4
• 1,480,808,857 events
• 8 terabytes of primary data
• 35 nodes
• 420GB RAM on primaries
• 21TB SSD storage
• 14TB EBS storage
• 120,000 ops/s

5. • Model
• Scale
• Grow
• Extend
5

6. 6
Model

7. November 2009 — MongoDB 1.2
• More indexes per collection
• Faster index creation
• Map/Reduce
• Stored JavaScript functions
• Configurable fsync time
• Several small features and fixes
7
{.}

8. 8
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9. 9
Decoding/Unmarshalling
Django ORM
{.}
[---]
business logic
RESTAPI
MySQL

10. 10
Decoding/Unmarshalling
Django ORM
RESTAPI {.}
[---]
business logic
MySQL

11. 11
Inning
Outs
Balls
Strikes
Pitcher
Batter

12. 12
Inning
Outs
Balls
Strikes
Pitcher
Batter
Period
Minute
Location
Shooter
Rebounder
Assist

13. 13
[play]
[participant]
[role]
[sport]
[play_property]

14. 14
[play]
[participant]
[role]
[sport]
[play_property]

15. 15
{_id: ObjectId(),
code: “1B”,
participants: [{player_id: ObjectId(),
roles: [“batter”, “out”]},
{player_id: ObjectId(),
roles: [“pitcher”]}],
situation: {outs: 1,
balls: 2,
strikes: 0},
properties: {location: [0.45, 0.721]}}

16. 16
{_id: ObjectId(),
code: “shot”,
participants: [{player_id: ObjectId(),
roles: [“shooter”]},
{player_id: ObjectId(),
roles: [“rebounder”]}],
situation: {period: 1,
time: 5:29},
properties: {location: [0.45, 0.721]}}

17. 17
Decoding/Unmarshalling
Django ORM
RESTAPI {.}
business logic
{.}MongoDB

18. 18
Decoding/Unmarshalling
Django ORM
RESTAPI {.}
business logic
{.}MongoDB
👏

19. 19

20. Modeling data in MongoDB
20
• JSON won the internet
• Don’t write your own JSON storage engine
• Flexible schemas promote app simplicity
• Validation is your responsibility
• Invest in schema design early

21. 21
Scale

22. 22

23. 23

24. 24

25. 25
$$$

26. 26
$$$
😱

27. 27
User Load
System Latency

28. 28
User Load
System Latency

29. 29
User Load
System Latency

30. 30
Scaling is the process of decoupling
load from latency.

31. Latency comes from
31
• Writing data to your database
• Reading data from your database
• Aggregating data from multiple locations
• Running complex calculations

32. 32
{.}
This is a document.

33. 33
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API MongoDB Browser

34. 34
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API MongoDB Browser

35. 35
{.} {.}
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API MongoDB Browser
+/-*

36. 36
Read Load
System Latency

37. 37
{.} {.}
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{.}
API MongoDB Browser

38. 38
{.} {.}
{.}
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{.}
API MongoDB Browser
+/-*

39. 39
Write Load
System Latency

40. 40
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{.}
API MongoDB Browser
Background+/-*

41. 41
{.} {.}
{.}
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{.}
API MongoDB Browser
Background+/-*

42. 42
User Load
System Latency

43. 43
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44. 44
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}

45. 45
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}

46. 46

47. Scaling data access
47
• Decouple load from latency
• Queries are expensive
• Aggregation is expensive
• Do calculation in the background
• Serve content from single* documents

48. 48
Grow

49. 49

50. 50

51. 51

52. 52
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53. 53
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54. 54
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55. 55
{.}

56. 56

57. 57
{.} {$addToSet: {a: 2}}

58. 58
{.} {$addToSet: {a: 2}}
{.} {v: 2}, {$set: {v: 3}}

59. 59
{.}

60. 60

61. 61
{.} {.}

62. 62
{a}
{abc}{b}
{c}
}

63. 63
{.}

64. 64
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65. 65
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66. 66
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67. 67
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68. 68
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69. 69
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70. 70
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71. 71
<id>
<id>
<id>
<id>
<id>
<id>
<id>
To Propagate

72. 72
<id>
<id>
<id>
<id>
<id>
<id>
<id>
To Propagate Propagating…

73. 73
<id>
<id>
<id>
<id>
<id>
<id>
<id>
To Propagate Propagating…
<id> {.}
{.}
{.}

74. 74
{$} {$} {$} {$} {$}

75. Growing load
75
• Denormalize for constant access time
• Use MongoDB atomic operators
• Check out optimistic locking and MVCC
• Leverage external concurrency control
• Watch your oplog

76. 76
Extend

77. 77
{.} +

78. 78

79. 79

80. 80

81. So there we have it
• Design your schema to MongoDB’s strengths
• Use monolithic documents
• Don’t do (live) querying
• You can still do transactional things
• You may need to denormalize & propagate
• Think about your overall architecture
81

82. 82
• have a sense of humor
• know what use cases work best
• remember that databases are hard
• don’t understate the difficulty in scaling up
@holacrat