How do you survive failure? You distribute. But distributed systems are distressingly complicated, everything from PAXOS to RAFT. Can we do better? Can we simplify things while still achieving reasonable results? This talk will explore a new method for conflict resolution that has been in the works for 5 years of R&D, and promises to mathematically ease the pain. All work is open source and has been implemented in the GUN database, a VC backed startup. We'll demonstrate some amazing recoveries from harsh failures and go into detail about how the fully peer-to-peer distributed algorithm works. We'll also discuss its weaknesses, where it fits in the CAP Theorem, and how it can be used as a building block for higher level consistency guarantees. You'll come out of the talk with a fresh perspective on concurrency that will help you make better decisions for your company's tough distributed problems. Ones based on mathematics and science, not hype of buzz words and marketing.

1. Conflict Resolution
with guns

2. Controversy

3. What is distributed?
time & space

4. Time

5. Space

6. Coordination

7. Failure

8. Master-Slave

9. Failure?

11. Leader-Election

12. or just not responding?
Dead?

23. CAP Theorem
Consistency, Availability, Partition tolerance

26. Can we do better?
PAXOS! RAFT!

27. Complexity

28. Challenge
Consistency

29. Challenge
Centralization

30. Conflict Resolution
with guns

31. In Space!

32. :(
or on the metro

33. Cause we Can’t Beat Light

35. 5

36. 2

37. -3

38. a quantifiable difference
Where “Quantum” Mechanics Comes From

39. The Universe
is not Strongly Consistent

41. Who Wins?
Hello: “Mars”
Hello: “Earth”

42. Divergence
Hello: “Mars” Hello: “Earth”

43. Terrible Timestamps
I’m from the future `yo!

44. Villainous Vectors
I catch your drift, but you lost me.

45. Alice says “Hello World” at 1
Alice says “Hello Mars” at 2
Bob says “Hello Jupiter” at 5
Alice says “Hello Pluto” at 6

46. I’m Carl and
I want to be
your friend!

47. c
No.

50. Can we do better?
or back to strong consistency?

51. Boundary Function

52. Operating State

53. Historical State

54. Deferred State

55. ?
?

56. state 8
state 4

57. Hello: “Mars”
state 9
state 8
state 4

58. Hello: “Mars”
state 9
state 8
state 4
✖ Process Later

59. Hello: “Sun”
state 3
state 8
state 4

60. Hello: “Sun”
state 3
state 8
state 4
✖ Record & Discard

61. Hello: “Venus”
state 5
state 8
state 4

62. Hello: “Venus”
state 5
state 8
state 4
✔ Process

63. state 8
state 5

64. state 9
state 5

65. state 9
state 5
Hello: “Earth”
state 9
✔ Process

66. state 9

67. state 9

68. Hello: “Mars”
state 9
state 9
state 12

69. State 9 === State 9
Conflict!

70. ?
value === value

71. Earth vs Mars
current value compared to incoming value

72. Naïve
lexical alphanumeric sort

73. Hello: “Mars”
state 9
state 12
Hello: “Earth”
state 9

74. Convergence
Hello: “Mars” Hello: “Mars”

75. Eventually

76. What Could Go Wrong?

77. function HAM(machineState, incomingState, currentState, incomingValue, currentValue){
if(machineState < incomingState){
return {amnesiaQuarantine: true};
}
if(incomingState < currentState){
return {quarantineState: true};
}
if(currentState < incomingState){
return {converge: true, incoming: true};
}
if(incomingState === currentState){
if(incomingValue === currentValue){
return {state: true};
}
if(String(incomingValue) < String(currentValue)){
return {converge: true, current: true};
}
if(String(currentValue) < String(incomingValue)){
return {converge: true, incoming: true};
}
}
return {err: "Invalid recursion"};
}

79. NTP

80. Linked Lists & Directed Acyclic Graphs
Causality

81. Conflict-free Replicated Data Types
X + Y - Z * A / B ^ C

82. Vulnerable to the Double Spending Problem
Math → Banking

83. Proof of Work
Blockchain Ledger

84. Extensible
Batteries Not Included

85. Your Business

86. Distributed Matters

87. Decentralized Matters

88. Math Matters

89. Science Matters
CRDTs, DAGs, Blockchains

90. c
Hey!

92. Will you
be my
friend?

94. People Matter
mark@gunDB.io