Supavisor Demo

Mix.install([
  {:postgrex, "~> 0.16.3"},
  {:kino, "~> 0.10.0"}
])

Some more setup

child = {DynamicSupervisor, strategy: :one_for_one, name: SvDemo.DynamicSupervisor}

{:ok, _pid} = Kino.start_child(child)

Configure our connection

# :ssl.start()

# sni_host = "db.ybkqkhkptkgmnlqjwtta.supabase.co"

pass = System.fetch_env!("LB_SUPAVISOR_DEMO_PASS")

# Supavisor
opts = [
  hostname: "aws-0-us-west-1.pooler.supabase.com",
  port: 6543,
  # Include your project ref in the username
  username: "postgres.ybkqkhkptkgmnlqjwtta",
  password: pass,
  database: "postgres"
  # ssl: true,
  # ssl_opts: [
  #   verify: :verify_none,
  #   server_name_indication: to_charlist(sni_host)
  # ]
  # socket_options: [:inet6]
]

connections = 50

pool =
  for _c <- 1..connections do
    {:ok, _conn} = DynamicSupervisor.start_child(SvDemo.DynamicSupervisor, {Postgrex, opts})
  end

DynamicSupervisor.count_children(SvDemo.DynamicSupervisor)

{:ok, conn} = Enum.random(pool)

Postgrex.query(conn, "select 1 as one", [])

Postgrex.query(
  conn,
  "select count(*) from pg_stat_activity where application_name ilike '%Supavisor%'",
  []
)

for {:ok, conn} <- pool do
  Postgrex.query(
    conn,
    "select 1 as one",
    []
  )
end