Let's create stateful systems, by Elixir

Transcript

1. Let's create stateful systems, by Elixir

2. . ｡oO( さっちゃんですよヾ( 〃l _ l) ﾉﾞ☆)

3. I'll show you a number.

4. 2

5. Two

6. Ⅱ

7. ⼆

8. 2 is a number of collison & collaboration.

9. I & you hot & ice stand up & lie

   down inside & outside

10. stateless & stateful

11. Function is stateless. f : x -> y e.g. Web

    server

12. Dialogue is stateful. Alice : X. Bob : Y. Alice

    : X. Bob : Z. Most of the system is stateful.

13. Elixir

14. Elixir is a functional programming language. Functional programming is stateless.

    All data of Elixir is immutable. [x, 3, x] = Enum.map([1,2,1], &(&1 + 1)) assert 2 == x // Many lines that don't reassign to `x`. assert 2 == x

15. Elixir has processes. 29 = Task.async(fn -> 29 end) |>

    Task.await

16. Process has state. agent = Agent.start_link(fn -> 29 end) 29

    = Agent.get(agent, &(&1)) Agent.update(agent, &(&1 + 13)) 42 = Agent.get(agent, &(&1))

17. State should be updated in a transaction. State shold interact

    & isolate each other. Accessing to state should be scaled in-out. Server with state should be updated gracefully. Elixir has all of these!

18. State should be updated in a transaction. (No shared state)

    State shold interact & isolate each other. (Application, Supervisor) Accessing to state should be scaled in-out. (GenStage, Task, Register, Erlang cluster) Server with state should be updated gracefully. (Hot code swap)

19. We can create stateful system easy, by constructing stateless parts.

20. How we can start Elixir? Let's create some applications. *

    Web application with Phoenix. * Slack bot.

21. Phoenix is a Web application framework that familiar with WebSocket.

    https://hexdocs.pm/phoenix/overview.html

22. React is available (✿ >ヮ ╹ )-♡ Let's create a

    realtime interaction ∩ (＞ ◡ ＜*)∩ ♡ https://speakerdeck.com/ne_sachirou/phoenix-livereact

23. Create a Slack bot. https://github.com/BlakeWilliams/Elixir-Slack (Easy, so no topic.)

24. Installing Elixir. asdf https://asdf-vm.com/ asdf plugin-add erlang asdf install erlang

    22.0.7 asdf plugin-add elixir asdf install elixir 1.9.1

25. Text editor? VSCode with mjmcloug.vscode-elixir works.

26. Format & lint. InnerCotton https://github.com/ne-sachirou/inner_cotton is a set of standard

    development tools. mix cotton.init mix cotton.lint --fix

27. Docker image (You need Docker :-) Fix major ver.s both

    Erlang & Elixir. docker run -it --rm nesachirou/elixir:1.9_erl22

28. Textbook & document. Official guide : https://elixir-lang.org/ Official document :

    https://hexdocs.pm/elixir/Kernel.html Online textbook : https://elixirschool.com/ja/ Textbook : https://tatsu-zine.com/books/programming-elixir-ja

29. https://speakerdeck.com/ne_sachirou/elixirwan-quan-nili-jie-sita

30. Advanced resources

31. Erlang in Anger https://ymotongpoo.github.io/erlang-in-anger/text-ja.pdf You want to read this… before

    production.

32. https://speakerdeck.com/ne_sachirou/sutetohurudeda-gui-mo- akusesufalsearusoft-realtimenagemusabawoeasynitukuru

33. https://speakerdeck.com/ne_sachirou/elixir-on-containers

34. https://speakerdeck.com/ne_sachirou/phoenix-at-scale

35. https://speakerdeck.com/ne_sachirou/ddd-data-driven-development