stevedomin/backstage

Backstage

Backstage is a simple Elixir background job processing library backed by PostgreSQL.

Usage

defmodule MyApp.Jobs.WelcomeNotification do
  use Backstage.Job, repo: MyApp.Repo

  def run(%{user_id: user_id}) do
    user = Repo.get!(MyApp.User, user_id)
    UserEmail.welcome(user) |> Mailer.deliver!
  end
end

iex> {:ok, job} = MyApp.Jobs.WelcomeNotification.new(%{user_id: user.id}) |> Repo.insert

Installation

If available in Hex, the package can be installed as:

1. Add backstage to your list of dependencies in mix.exs:

```elixir
def deps do
  [{:backstage, "~> 0.1.0"}]
end
```

2. Ensure backstage is started before your application:

```elixir
def application do
  [applications: [:backstage]]
end
```

3. Start the backstage supervisor:

```elixir
def start(_type, _args) do
  import Supervisor.Spec

  children = [
    supervisor(Backstage.Supervisor, [])
  ]

  opts = [strategy: :one_for_one, name: MyApp.Supervisor]
  Supervisor.start_link(children, opts)
end
```

TODO

• Logging
• #1 (comment)
• Currently polling Postgres for new jobs every X ms. Could we use LISTEN/NOTIFY?
• Think about the implications of gen_stage events buffering
• Make it possible to destroy the job as part of a transaction in "userland"
• Retries/backoff
• Vacuum the failed jobs?
• UI to list jobs, failures, retry, etc.
  • Separate package
• scheduler
• benchmarking