Simplifying systems with Elixir - Belgrade

Transcript

1. Simplifying systems
   with Elixir
   @sasajuric
   aircloak.com
   

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2. Elixir
   functional
   concurrent
   

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3. process
   ...
   foo(...)
   bar(...)
   ...
   

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4. functional Elixir
   modules and functions
   immutable data
   first-class functions
   

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5. ...
   spawn(fn -> ... end)
   ...
   

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6. process A
   ...
   foo(...)
   bar(...)
   ...
   process B
   ...
   baz(...)
   qux(...)
   ...
   

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7. send(
   process_b,
   some_message
   )
   receive do
   message ->
   handle(message)
   end
   process a process b
   

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8. BEAM (Erlang VM)
   

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9. BEAM (Erlang VM)
   

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10. scheduler scheduler scheduler scheduler
    BEAM (Erlang VM)
    CPU CPU CPU CPU
    

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11. concurrent
    functional
    

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12. activities
    incoming requests
    background jobs
    in-memory state
    load control
    …
    

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13. managing activities
    multiple OS processes
    3rd party products
    service managers
    

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16. uniformity
    simpler development
    simpler testing
    simpler deployment
    simpler maintenance
    improved collaboration
    

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18. theerlangelist.com
    

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19. git clone https://github.com/sasa1977/erlangelist.git
    mix deps.get && pushd assets && npm install && popd
    iex -S mix phx.server
    

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21. serving requests
    

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22. http listener https listener
    

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23. http listener https listener
    handler 1 handler 2 handler n
    …
    

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24. usage stats
    

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25. stats collector
    handler
    handler handler
    

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26. stats collector
    disk writer
    

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27. def store(path, data) do
    File.write!(
    path,
    :erlang.term_to_binary(data)
    )
    end
    

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28. def read(path, default) do
    path
    |> File.read!()
    |> :erlang.binary_to_term()
    rescue ArgumentError ->
    default
    end
    

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29. cleanup
    

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30. scheduler cleanup job
    periodically starts
    

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31. HTTPS
    

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32. our system CA server
    certificate request
    challenge info
    challenge
    

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33. certifier
    http server
    usage stats
    

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34. dev CA server
    

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35. service management
    

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36. defmodule StatsCollector do
    def start_link() do
    # ...
    end
    # ...
    end
    

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37. Supervisor.start_link(
    [
    StatsCollector,
    Cleanup
    ],
    # ..
    )
    

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38. supervisor
    stats collector cleanup
    

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39. supervisor
    worker
    

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42. 1
    2
    3 4 5
    

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43. 1
    2 6 9
    7 8
    3 4 5
    

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44. erlangelist
    usage stats web
    

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45. usage stats
    stats collector cleanup
    

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46. web
    ACME server main site certifier
    

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48. technical feature built-in options
    services GenServer, Task
    service manager Supervisor
    service registry Registry
    k-v ets, mnesia
    web server phoenix, plug, cowboy
    periodical jobs :timer, quantum, periodic
    load regulation jobs, safetyvalve, sbroker
    concurrent flows Flow, GenStage
    

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49. Elixir in a nutshell
    start simple
    go far
    

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50. Elixir guides
    Phoenix guides
    Learning resources
    Elixir forum
    

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51. 40% off using code
    ctwelixirbg18 at
    manning.com
    slides available at
    bit.ly/elixirbg102018
    

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