A PG/PG2 based notifier implementation that runs with Distributed Erlang.

Out of the box, Oban uses PostgreSQL's LISTEN/NOTIFY for PubSub. For most applications, that is fine, but Postgres-based PubSub isn't sufficient in some circumstances. In particular, Postgres notifications won't work when your application connects through PGbouncer in transaction or statement mode.

Note: You must be using Distributed Erlang to use the PG notifier.

usage

Usage

Specify the PG notifier in your Oban configuration:

config :my_app, Oban,
  notifier: Oban.Notifiers.PG,
  ...

implementation-notes

Implementation Notes

• The notifier will use pg if available (OTP 23+) or fall back to pg2 for older OTP releases.

• Like the Postgres implementation, notifications are namespaced by prefix.

• For compatibility, message payloads are always serialized to JSON before broadcast and deserialized before relay to local processes.

migrating-from-oban-notifiers-postgres

Migrating from Oban.Notifiers.Postgres

After switching from Oban.Notifiers.Postgres, you may remove the unused oban_notify trigger. Use the following migration to drop the trigger while retaining the oban_jobs_notify function:

defmodule MyApp.Repo.Migrations.DropObanJobsNotifyTrigger do
  use Ecto.Migration

  def change do
    execute(
      "DROP TRIGGER IF EXISTS oban_notify ON public.oban_jobs",
      "CREATE TRIGGER oban_notify AFTER INSERT ON public.oban_jobs FOR EACH ROW EXECUTE PROCEDURE public.oban_jobs_notify()"
    )
  end
end