CHANGELOG.md

Changelog for Oban v2.18

🌟 Looking for changes to Web or Pro? Check the Oban.Pro Changelog or the Oban.Web Changelog. 🌟

🔭 Queue Shutdown Telemetry

A new queue shutdown event, [:oban, :queue, :shutdown], is emitted by each queue when it terminates. The event originates from the watchman process, which tracks the total ellapsed time from when termination starts to when all jobs complete or the allotted period is exhausted.

Any jobs that take longer than the :shutdown_grace_period (by default 15 seconds) are brutally killed and left as orphans. The ids of jobs left in an executing state are listed in the event's orphaned meta.

This also adds queue:shutdown logging to the default logger. Only queues that shutdown with orphaned jobs are logged, which makes it easier to detect orphaned jobs and which jobs were affected:

[
  message: "jobs were orphaned because they didn't finish executing in the allotted time",
  queue: "alpha",
  source: "oban",
  event: "queue:shutdown",
  ellapsed: 500,
  orphaned: [101, 102, 103]
]

🚚 Distributed PostgreSQL Support

It's now possible to run Oban in distributed PostgreSQL databases such as Yugabyte. This is made possible by a few simple changes to the Basic engine, and a new unlogged migration option.

Some PostgreSQL compatible databases don't support unlogged tables. Making oban_peers unlogged isn't a requirement for Oban to operate, so it can be disabled with a migration flag:

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

  def up do
    Oban.Migration.up(version: 12, unlogged: false)
  end
end

🧠 Job Observability

Job stop and exception telemetry now includes the reported memory and total reductions from the job's process. Values are pulled with Process.info/2 after the job executes and safely fall back to 0 in the event the process has crashed. Reductions are a rough proxy for CPU load, and the new measurements will make it easier to identify computationally expensive or memory hungry jobs.

In addition, thanks to the addition of Process.set_label in recent Elixir versions, the worker name is set as the job's process label. That makes it possible to identify which job is running in a pid via observer or live dashboard.

v2.18.2 — 2024-08-16

Bug Fixes

• [Repo] Prevent debug noise by ensuring default opts for standard transactions.

  Without default opts each transaction is logged. Many standard operations execute each second, which makes for noisy logs. Now transaction opts are passed as a third argument to ensure defaults are applied.

• [Repo] Increase transaction retry delay and increase with each attempt.

  Bump the base transaction retry from 100ms to 500ms, and increase linearly between each successive attempt to provide deeper backoff. This alleviates pressure on smaller connection pools and gives more time to recover from contentions failures.

v2.18.1 — 2024-08-15

Enhancements

• [Repo] Automatically retry all transactions with backoff.

  Avoid both expected and unexpected database errors by automatically retrying transactions. Some operations, such as serialization and lock not available errors, are likely to occur during standard use depending on how a database is configured. Other errors happen infrequently due to pool contention or flickering connections, and those should also be retried for increased safety.

  This change is applied to Oban.Repo.transaction/3 itself, so it will apply to every location that uses transactions.

• [Migration] Declare tags as an array of text rather than varchar.

  We don't provide a limit on the size of tags and they could conceivably be larger than 256 characters. Externally the types are interchangeable, but internally there are minor advantages to using the text type.

  There isn't a new migration; this change is only for new tables.

Bug Fixes

• [Repo] Correctly dispatch query!/4 to query! rather than query without a bang.

v2.18.0 — 2024-07-26

Enhancements

• [Job] Support simple unique: true and unique: false declarations

  Uniqueness can now be enabled with unique: true and disabled with unique: false from job options or a worker definition. The unique: true option uses all the standard defaults, but sets the period to :infinity for compatibility with Oban Pro's new simple unique mode.

• [Cron] Remove forced uniqueness when inserting scheduled jobs.

  Using uniqueness by default prevents being able to use the Cron plugin with databases that don't support uniqueness because of advisory locks. Luckily, uniqueness hasn't been necessary for safe cron insertion since leadership was introduced and scheduling changed to top-of-the-minute many versions ago.

• [Engine] Introduce check_available/1 engine callback

  The check_available/1 callback allows engines to customize the query used to find jobs in the available state. That makes it possible for alternative engines, such Oban Pro's Smart engine, to check for available jobs in a fraction of the time with large queues.

• [Peer] Add Oban.Peer.get_leader/2 for checking leadership

  The get_leader/2 function makes it possible to check which node is currently the leader regardless of the Peer implementation, and without having to query the database.

• [Producer] Log a warning for unhandled producer messages.

  Some messages are falling through to the catch-all handle_info/2 clause. Previously, they were silently ignored and it degraded producer functionality because inactive jobs with dead pids were still tracked as running in the producer.

• [Oban] Use structured messages for most logger warnings.

  A standard structure for warning logs makes it easier to search for errors or unhandled messages from Oban or a particular module.

Bug Fixes

• [Job] Include all fields in the unique section of Job.t/0.

  The unique spec lacked types for both keys and timestamp keys.

• [Basic] Remove materialized option from fetch_jobs/3.

  The MATERIALIZED clause for CTEs didn't make a meaningful difference in job fetching accuracy. In some situations it caused a performance regression (which is why it was removed from Pro's Smart engine a while ago).