Elixir - Part 1

Transcript

1. Real-time Apps With Elixir Matthew Rudy Jacobs @ Codeaholics HK

2. THE PROBLEM SPACE

3. Line 100s of millions of online users Can’t lose a

   message Don’t want downtime

4. Uber 100,000s online users Can’t lose a message Don’t want

   downtime

5. GoGoVan ? online users Can’t lose a message Don’t want

   downtime

6. THE SOLUTION?

7. Erlang The Movie

8. Ericsson (in 1998) 99.9999999% UPTIME 32MS / YEAR

9. Ericsson (in 1998) 99.9999999% UPTIME < 1SECOND / 20 YEARS

10. None

11. Whatsapp 64 billion messages per day 700 million monthly active

    users 1000 servers doing the work

12. 4 Parts

13. Erlang Elixir OTP Phoenix

14. Part 1 Erlang

15. WHAT IS ERLANG?

16. Erlang • functional • concurrent • realtime

17. Erlang • pattern matching • message passing • actors •

    hot code reloading

18. -module(roman). -export([to_roman/1]). to_roman(0) -> []; to_roman(X) when X >= 1000

    -> [$M | to_roman(X - 1000)]; to_roman(X) when X >= 100 -> digit(X div 100, $C, $D, $M) ++ to_roman(X rem 100); to_roman(X) when X >= 10 -> digit(X div 10, $X, $L, $C) ++ to_roman(X rem 10); to_roman(X) when X >= 1 -> digit(X, $I, $V, $X). digit(1, X, _, _) -> [X]; digit(2, X, _, _) -> [X, X]; digit(3, X, _, _) -> [X, X, X]; digit(4, X, Y, _) -> [X, Y]; digit(5, _, Y, _) -> [Y]; digit(6, X, Y, _) -> [Y, X]; digit(7, X, Y, _) -> [Y, X, X]; digit(8, X, Y, _) -> [Y, X, X, X]; digit(9, X, _, Z) -> [X, Z]. Complex? Ugly?
19. None

20. Part 2 OTP

21. OTP IS A FRAMEWORK

22. OTP IS A SET OF CONVENTIONS

23. YOUR APPLICATION IS MADE OF “SERVERS” “AGENTS” AND “STATE MACHINES”

    KEPT ALIVE BY A COMPLICATED TREE OF SUPERVISORS
24. None

25. Part 3 Elixir

26. Jose Valim

27. #4 Rails Contributor

28. Creator of Devise

29. Creator of Elixir

30. “I felt the same way I felt when I first

    saw Ruby.”

31. ERLANG AND RUBY HAD A BABY

32. %%% erlang -module(recursve). -export([fac/1]). fac(N) when N == 0 ->

    1; fac(N) when N > 0 -> N*fac(N-1). # Ruby module Recursive def fac(n) return 1 if n == 0 fail ArgumentError unless n > 0 n*fac(n-1) end end

33. # Elixir defmodule Recursive do def fac(n) when n ==

    0, do: 1 def fac(n) when n > 0 do n*fac(n-1) end end

34. # Elixir - with tail call defmodule Recursive do def

    fac(0), do: 1 def fac(n) when n > 0 do fac(n, 1) end defp fac(1, acc), do: acc defp fac(n, acc) do fac(n-1, acc*n) end end

35. “str”<>”ings”

36. :atoms

37. "with #{:interpolation}"

38. [:list, “type”]

39. {:tuple, “type”}

40. [key: “word”, list: “…”]

41. %{map: “is”, like: “a hash”}

42. defmodule My.Module do def exported() do 42 end defp private()

    do 76 end end

43. [head|tail] = [:a, :b, :c]

44. defmodule Math do def sum([head|tail], acc) do sum(tail, head +

    acc) end def sum_list([], acc) do acc end end

45. bessy = %{ type: “cow”, name: “bessy” } %{name: name}

    = bessy name == “bessy”

46. fn x -> 2*x end

47. list = [1,3,3,7] Enum.sum( Enum.map(list, fn x -> x*x end)

    ) # 68

48. [1,3,3,7] |> Enum.map(fn x -> x*x end) |> Enum.sum #

    68

49. > iex

50. Part 4 Phoenix

51. Elixir on Phoenix

52. Phoenix Ecto for the database Plug for routing Channels for

    websockets

53. mix phoenix.new phoenix_play

54. MORE NEXT TIME

55. Appendix A Thoughts

56. Gateway Todos Users Auth SERVICES OVER HTTP Mailer Search •HTTP

    •Ports •Monitoring •Scaling •Logging Issues

57. Gateway Todos Users Auth A SINGLE OTP SYSTEM Mailer Search

    •HTTP •Ports •Monitoring •Scaling •Logging Issues

58. Ruby people finally with technology that can scale

59. PEPE Postgres Elixir Phoenix Ember

60. Appendix B Addendum

61. None

62. THANKS

63. None

64. COME WORK AT GOGOVAN!!!