Simplifying systems with Elixir - Belgrade

Transcript

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   Simplifying systems with Elixir @sasajuric aircloak.com

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   Elixir functional concurrent

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

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   functional Elixir modules and functions immutable data first-class functions

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

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

   qux(...) ...
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   send( process_b, some_message ) receive do message -> handle(message) end

   process a process b
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   BEAM (Erlang VM)

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   BEAM (Erlang VM)

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    scheduler scheduler scheduler scheduler BEAM (Erlang VM) CPU CPU CPU

    CPU
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    concurrent functional

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

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    managing activities multiple OS processes 3rd party products service managers

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    None
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    None
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    uniformity simpler development simpler testing simpler deployment simpler maintenance improved

    collaboration
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    None
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    theerlangelist.com

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    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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    None
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    serving requests

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    http listener https listener

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    http listener https listener handler 1 handler 2 handler n

    …
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    usage stats

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    stats collector handler handler handler

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    stats collector disk writer

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

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

    ArgumentError -> default end
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    cleanup

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    scheduler cleanup job periodically starts

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    HTTPS

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    our system CA server certificate request challenge info challenge

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    certifier http server usage stats

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    dev CA server

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    service management

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

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

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    supervisor stats collector cleanup

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    supervisor worker

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    1

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    1 2

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    1 2 3 4 5

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    1 2 6 9 7 8 3 4 5

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    erlangelist usage stats web

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    usage stats stats collector cleanup

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    web ACME server main site certifier

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    None
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    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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    Elixir in a nutshell start simple go far

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    Elixir guides Phoenix guides Learning resources Elixir forum

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    40% off using code ctwelixirbg18 at manning.com slides available at

    bit.ly/elixirbg102018