Oban Pro v1.4 is out!
Streamlined Workflows
Workflows now use automatic scheduling to run workflow jobs in order, without any polling or
snoozing. Jobs with upstream dependencies are automatically marked as on_hold and scheduled far
into the future. After the upstream dependency executes they’re made available to run, with
consideration for retries, cancellations, and discards.
-
An optimized, debounced query system uses up to 10x fewer queries to execute slower workflows.
-
Queue concurrency limits don’t impact workflow execution, and even complex workflows can quickly
run in parallel with global_limit: 1 and zero snoozing.
-
Cancelled, deleted, and discarded dependencies are still handled according to their respective
ignore_* policies.
All of the previous workflow “tuning” options like waiting_limit and waiting_snooze are gone,
as they’re not needed to optimize workflow execution. Finally, older “in flight” workflows will
still run with the legacy polling mechanism to ensure backwards compatibility.
Job Execution Deadlines
Jobs that shouldn’t run after some period of time can be marked with a deadline. After the
deadline has passed the job will be pre-emptively cancelled on its next run, or optionally
during its next run if desired.
defmodule DeadlinedWorker do
use Oban.Pro.Worker, deadline: {1, :hour}
@impl true
def process(%Job{args: args}) do
# If this doesn't run within an hour, it's cancelled
end
end
Deadlines may be set at runtime as well:
DeadlinedWorker.new(args, deadline: {30, :minutes})
In either case, the deadline is always relative and computed at runtime. That also allows the
deadline to consider scheduling—a job scheduled to run 1 hour from now with a 1 hour deadline will
expire 2 hours in the future.
Automatic Crontab Syncing
Synchronizing persisted entries manually required two deploys: one to flag it with deleted: true
and another to clean up the entry entirely. That extra step isn’t ideal for applications that
don’t insert or delete jobs at runtime.
To delete entries that are no longer listed in the crontab automatically set the sync_mode
option to :automatic:
[
sync_mode: :automatic,
crontab: [
{"0 * * * *", MyApp.BasicJob},
{"0 0 * * *", MyApp.OtherJob}
]
]
To remove unwanted entries, simply delete them from the crontab:
crontab: [
{"0 * * * *", MyApp.BasicJob},
- {"0 0 * * *", MyApp.OtherJob}
]
With :automatic sync, the entry for MyApp.OtherJob will be deleted on the next deployment.
Upgrading to v1.4 {: .warning}
Changes to DynamicCron require a migration to add the new insertions column. You must
re-run the Oban.Pro.Migrations.DynamicCron migration when upgrading.
defmodule MyApp.Repo.Migrations.UpdateObanCron do
use Ecto.Migration
defdelegate change, to: Oban.Pro.Migrations.DynamicCron
end
v1.4.0 — 2024-03-21
Enhancements
-
[DynamicCron] Add :sync_mode for automatic entry management.
Most users expect that when they delete an entry from the crontab it won’t keep running after
the next deploy. A new sync_mode option allows selecting between automatic and manual
entry management.
In addition, this moves cron entry management into the evaluate handler. Inserting and deleting
at runtime can’t leverage leadership, because in rolling deployments the new nodes are never
the leader.
-
[DynamicCron] Use recorded job insertion timestamps for guaranteed cron.
A new field on the oban_crons table records each time a cron job is inserted up to a
configurable limit. That field is then used for guaranteed cron jobs, and optionally for
historic inspection beyond a job’s retention period.
-
[DynamicCron] Stop adding a unique option when inserting jobs, regardless of the guaranteed
option.
There’s no need for uniqueness checks now that insertions are tracked for each entry. Inserting
without uniqueness is significantly faster.
-
[DynamicCron] Inject cron information into scheduled job meta.
This change mirrors the addition of cron: true and cron_expr: expression added to Oban’s
Cron in order to make cron jobs easier to identify and report on through tools like Sentry.
-
[Worker] Add :deadline option for auto cancelling jobs
Jobs that shouldn’t run after some period of time can be marked with a deadline. After the
deadline has passed the job will be pre-emptively cancelled on its next run, or optionally
during its next run if desired.
-
[Workflow] Invert workflow execution to avoid bottlenecks caused by polling and snoozing.
Workflow jobs no longer poll or wait for upstream dependencies while executing. Instead, jobs with dependencies are “held” until they’re made available by a facilitator function. This nverted flow makes fewer queries, doesn’t clog queues with jobs that aren’t ready, avoids snoozing, and is generally more efficient.
-
[Workflow] Expose functions and direct callback docs to function docs.
Most workflow functions aren’t true callbacks, and shouldn’t be overwritten. Now all callbacks point to the public function they wrap. Exposing workflow functions makes it easier to find and link to documentation.
Bug Fixes
-
[DynamicCron] Don’t consider the node rebooted until it is leader
With rolling deploys it is frequent that a node isn’t the leader the first time it evaluates. However, the :rebooted flag was set to true on the first run, which prevented reboots from being inserted when the node ultimately acquired leadership.
-
[DynamicQueues] Accept streamline partition syntax for global_limit and rate_limit options.
DynamicQueues didn’t normalize the newer partition syntax before validation. This was an oversight, and a sign that validation had drifted between the Producer and Queue schemas. Now schemas use the same changesets to ensure compatibility.
-
[Smart] Handle partitioning by :worker and :args regardless of order.
The docs implied partitioning by worker and args was possible, but there wasn’t a clause that handled any order correctly.
-
[Smart] Explicitly cast transactional advisory lock prefix to integer.
Postgres 16.1 may throw an error that it’s unable to determine the argument type while taking bulk unique locks.
-
[Smart] Preserve recorded values between retries when sync acking failed.
Acking a recorded value for a batch or workflow is synchronous, and a crash or timeout failure
would lose the recorded value on subsequent attempts. Now the value is persisted between retries
to ensure values are always recorded.
-
[Smart] Revert “Force materialized CTE in smart fetch query”.
Forcing a materialized CTE in the fetch query was added for reliability, but it can cause performance regressions under heavy workloads.
-
[Testing] Use configured queues when ensuring all started.
Starting a supervised Oban in manual mode with tests specified would fail because in :manual testing mode the queues option is overridden to be empty.
DynamicPartitioner
Scheduling Guarantees
UUIDv7 for Binary Ids
Async Tracking
