load_tester.ex

defmodule LoadTester do
  @table_name :http_results
  @url "https://example.com"

  def test() do
    tab =
      :ets.new(table_name, [
        :set,
        :named_table,
        :public,
        read_concurrency: true,
        write_concurrency: true
      ])

    for i <- 1..100_000, do: Task.async(&make_request/0)

    :ets.tab2list(@table_name)
    |> Enum.sort(fn {s, _} -> s end)
    |> Enum.each(fn {s, c} -> IO.puts("Encountered #{s} #{c} times") end)
  end

  def make_request() do
    case :hackney.request(:get, @url, [], "", with_body: true) do
      {:ok, status, _, _} ->
        :ets.update_counter(@table_name, status, {2, 1}, {status, 0})

      {:error, _} ->
        :ets.update_counter(@table_name, :error, {2, 1}, {:error, 0})
    end
  end
end