Parallel processing

parallel.ex

defmodule Worker do
  def work(num) do
    "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat."
    |> String.split
    |> Enum.map(&String.upcase/1)
    |> Enum.join
  end
end

iterations = 100000

{us, :ok} = :timer.tc fn ->
  0..iterations |>
    Stream.map(&Task.async(Worker, :work, [&1])) |>
    Enum.each(&Task.await(&1))
end

IO.puts "Time executing #{iterations} jobs in parallel: #{us/1000}ms"

{us, :ok} = :timer.tc fn ->
  0..iterations |>
    Enum.each(&Worker.work(&1))
end

IO.puts "Time executing #{iterations} jobs sequentially: #{us/1000}ms"

In this version, sequential is, indeed faster:

Time executing 100000 jobs in parallel: 7767.314ms
Time executing 100000 jobs sequentially: 5176.606ms