Elixir Recurrent Jobs

Recurrent Jobs

Runtime jobs are first-party supervised processes, not Oban workers.

Shape

Domain jobs live under the owning context's jobs/, and the context module supervises them:

defmodule Emisar.Runs.Jobs.DispatchTimeout do
  use Emisar.Jobs.Job,
    otp_app: :emisar,
    every: :timer.minutes(1),
    executor: Emisar.Jobs.Executors.GloballyUnique

  @impl Emisar.Jobs.Executors.GloballyUnique
  def execute(config) do
    # Poll durable rows and make idempotent transitions.
    :ok
  end
end

The owning context starts its jobs:

defmodule Emisar.Runs do
  use Supervisor

  def start_link(opts), do: Supervisor.start_link(__MODULE__, opts, name: __MODULE__.Supervisor)

  @impl Supervisor
  def init(_opts) do
    Supervisor.init([Jobs.DispatchTimeout], strategy: :one_for_one)
  end
end

Emisar.Jobs is infrastructure only: declaration macro + executors. Do not put domain sweep engines in top-level Emisar.Jobs and do not recreate lib/emisar/workers/.

Iron Law IL-13

1. Idempotent. A tick may run more than once after restarts, failover, or a crash. Check current row state before acting.
2. Durable rows, not scheduler memory. The scheduler has no persistent queue; each tick polls rows with durable state and bounded queries.
3. No overlapping-work assumptions. GloballyUnique elects one leader per job across the cluster, but the job logic must still be safe if a previous tick's side effects partially completed.

Wiring

• Keep the job under the owning context's jobs/.
• Add that context to Emisar.Application if it is not already a supervised child.
• Disable job modules explicitly in config/test.exs; tests call execute/1 directly so all DB work stays inside the test sandbox checkout.
• If a job needs another context's table shape, add a narrow internal function on the owning context instead of building a sibling context's Query pipeline.

Testing

• Run the job directly: JobModule.execute([]) or with keyword config.
• Cover the idempotency path: run execute/1 twice, assert the second is a no-op.
• For a sweep, cover happy, nothing-to-do, cross-account scoping, and bounded pagination/batch behavior.

Finish

Run ./run gate portal --changed from the repository root. Run the complete ./run gate portal before pushing.