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oban v2.9.0 Release Notes

Release Date: 2021-09-15 // over 2 years ago

  • 👷 Optionally Use Meta for Unique Jobs

    👷 It's now possible to use the meta field for unique jobs. Unique jobs have 👷 always supported worker, queue, and args fields. That was flexible, but 👮 forced applications to put ad-hoc unique values in args when they should really be in meta.

    👍 The meta field supports keys, just like args. That makes it possible to 💅 use highly efficient fingerprint style uniqueness (and possibly drop the index on args, if desired).

    🖨 Here's an example of using a single "fingerprint" key in meta for uniqueness:

    defmodule MyApp.FingerprintWorker do
  use Oban.Worker, unique: [fields: [:worker, :meta], keys: [:fingerprint]]

  @impl Worker
  def new(args, opts) do
    fingerprint = :erlang.phash2(args)

    super(args, Keyword.put(opts, :meta, %{fingerprint: fingerprint}))
  end
end

    0️⃣ For backward compatibility meta isn't included in unique fields by default.

    Expanded Start and Scale Options

    🔨 After extensive refactoring to queue option management and validation, now it's 👍 possible to start and scale queues with all supported options. Previously 👍 start/stop functions only supported the limit option for dynamic scaling, reducing runtime flexibility considerably.

    Now it's possible to start a queue in the paused state:

    Oban.start_queue(queue: :dynamic, paused: true)

    👍 Even better, for apps that use an alternative engine like the SmartEngine from Oban Pro, it's possible to start a dynamic queue with options like global concurrency or rate limiting:

    Oban.start_queue(queue: :dynamic, local_limit: 10, global_limit: 50)

    All options are also passed through scale_queue, locally or globally, even 👍 allowing you to reconfigure a feature like rate limiting at runtime:

    Oban.scale_queue(queue: :dynamic, rate_limit: [allowed: 50, period: 60])

    ➕ Added

    • [Oban] Add Oban.cancel_all_jobs/1,2 to cancel multiple jobs at once, within an atomic transaction. The function accepts a Job query for complete control over which jobs are cancelled.

    • [Oban] Add Oban.retry_all_jobs/1,2 to retry multiple jobs at once, within an atomic transaction. Like cancel_all_jobs, it accepts a query for fine-grained control.

    • [Oban] Add with_limit option to drain_queue/2, which controls the number of jobs that are fetched and executed concurrently. When paired with with_recursion this can drastically speed up interdependent job draining, i.e. workflows.

    • [Oban.Telemetry] Add telemetry span events for all engine and notifier actions. Now all database operations are covered by spans.

    • [Oban.Migrations] Add create_schema option to prevent automatic schema creation in migrations.

    🔄 Changed

    • [Oban] Consistently include a :snoozed count in drain_queue/2 output. Previously the count was only included when there was at least one snoozed job.

    • ✅ [Oban.Testing] Default to attempt: 1 for perform_job/3, as a worker's perform/1 would never be called with attempt: 0.

    🛠 Fixed

    • [Oban.Queue.Supervisor] Change supervisor strategy to :one_for_all.

    Queue supervisors used a :rest_for_one strategy, which allowed the task supervisor to keep running when a producer crashed. That allowed duplicate long-lived jobs to run simultaneously, which is a bug in itself, but could also cause attempt > max_attempts violations.

    • 🔌 [Oban.Plugins.Cron] Start step ranges from the minimum value, rather than for the entire set. Now the range 8-23/4 correctly includes [8, 12, 16, 20].

    • [Oban.Plugins.Cron] Correctly parse step ranges with a single value, e.g. 0 1/2 * * *

    • 📇 [Oban.Telemetry] Comply with :telemetry.span/3 by exposing errors as reason in metadata