sorentwo/oban v2.7.0

on GitHub

Pluggable Notifier

The PubSub functionality Oban relies on for starting, stopping, scaling, and pausing queues is now pluggable. The previous notifier was hard-coded to use Postgres for PubSub via LISTEN/NOTIFY. Unfortunately, LISTEN/NOTIFY doesn't work for PG Bouncer in "Transaction Mode." While relatively few users run in "Transaction Mode," it is increasingly common and deserved a work-around.

Oban.Notifier defines a minimal behaviour and Oban ships with a default implementation, Oban.PostgresNotifier, based on the old LISTEN/NOTIFY module. You can specify a different notifier in your Oban configuration:

config :my_app, Oban,
  notifier: MyApp.CustomNotifier,
  repo: MyApp.Repo,
  ...

An alternate pg/pg2 based notifier is available in Oban Pro.

Replacing Opts on Unique Conflict

The replace_args option for updating args on unique conflict is replaced with a highly flexible replace option. Using replace, you can update any job field when there is a conflict. Replace works for any of the following fields: args, max_attempts, meta, priority, queue, scheduled_at, tags, worker.

For example, to change the priority to 0 and increase max_attempts to 5 when there is a conflict:

BusinessWorker.new(
  args,
  max_attempts: 5,
  priority: 0,
  replace: [:max_attempts, :priority]
)

Another example is bumping the scheduled time to 1 second in the future on conflict. Either scheduled_at or schedule_in values will work, but the replace option is always scheduled_at.

UrgentWorker.new(args, schedule_in: 1, replace: [:scheduled_at])

Added

• [Oban.Job] A new conflict? field indicates whether a unique job conflicted with an existing job on insert.

• [Oban.Telemetry] Always populate the unsaved_error field for error or discard events. Previously, the field was empty for discard events.

• [Oban.Queue.Engine] Define a cancel_job/2 callback in the engine and move cancellation from the query module to the BasicEngine.

Changed

• [Oban.Testing] Thanks to a slight refactoring, the perform_job/3 helper now emits the same telemetry events that you'd have in production. The refactoring also exposed and fixed an inconsistency around invalid snooze handlers.

• [Oban.Testing] Expose Testing.all_enqueued/0, an alternate clause that doesn't require any options. This new clause makes it possible to check for any enqueued jobs without filters.

• [Oban.Plugins.Stager] Limit the number of jobs staged at one time to prevent timeout errors while staging a massive number of jobs.

Fixed

• [Oban.Repo] Respect ongoing transactions when using get_dynamic_repo. Prior to this fix, calls that use Oban.Repo, such as Oban.insert/2, could use a different repo than the one used in the current transaction.