/demo_system

Primary LanguageElixir

Demo system

https://www.youtube.com/watch?v=JvBT4XBdoUE

Getting started

Requires Erlang, Elixir, and node.js, as specified in the .tool-versions file. You can use asdf for that.

load_control folder is a library directly being used by the example_system mix project, which is the demo app.

Building:

cd example_system
mix deps.get &&
pushd assets &&
npm install &&
popd &&
mix compile

Starting for development with live reload (recommended for following with youtube):

iex -S mix phx.server

Then, you can visit the following links:

Demo

Building and starting for production (in the background):

cd example_system
./rebuild.sh
./_build/prod/rel/system/bin/system start

Open the remote console:

./_build/prod/rel/system/bin/system remote_console

Hot upgrade with no downtime:

mix system.upgrade

Processes structure overview

Load

Application start

  1. ExampleSystem.Metrics.init/1
  • calls LoadControl.subscribe_to_stats/0
  1. LoadControl.subscribe_to_stats/0
  • is a defdelegate to LoadControl.Stats.subscribe/0
  1. LoadControl.Stats.subscribe/0
  • stores LoadControl pid to its subscribers list in state
  • because this was called via defdelegate, this function is viewed as if a public function of LoadControl

Routing to /load in browser

  1. ExampleSystemWeb.Load.Dashboard.mount/3
  • calls ExampleSystem.Metrics.subscribe/0
  1. ExampleSystem.Metrics.subscribe/0
  • gets the calling pid (Dashboard LiveView), stores into its list of subscribes in state