ExBreak

ExBreak is a circuit breaker implementation for Elixir.

When making function calls that may fail, you may find that you want to stop making those calls for a period of time after an error threshold is hit. This package provides a way to do that.

defmodule GitHub do
  @moduledoc """
  Makes calls to the GitHub API
  """

  @base_url "https://api.github.com"

  @doc """
  Make a GET request to the GitHub API.

  This request is wrapped in a circuit breaker—after 10 calls that return an
  error tuple (`{:error, any}`), the circuit breaker will trip, and the
  function will immediately return `{:error, :circuit_breaker_tripped}` for
  the next two minutes (120 seconds).
  """
  def get(path, token: token) do
    ExBreak.call(&do_get/2, [path, token], threshold: 10, timeout_sec: 120)
  end

  defp do_get(path, token) do
    HTTPoison.get("#{@base_url}#{path}", authorization: "Bearer #{token}")
  end
end

Installation

If available in Hex, the package can be installed by adding ex_break to your list of dependencies in mix.exs:

def deps do
  [
    {:ex_break, "~> 0.1.0"}
  ]
end

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/ex_break.