django-dbtasks 0.3.0

Database task backend and runner for Django tasks.

django-dbtasks

Database backend and runner for Django tasks (new in 6.0).

django-dbtasks is tested on PostgreSQL, SQLite, and MySQL for versions of Python back to 3.12, including the free-threading builds.

Note when using SQLite it is recommended to set OPTIONS["transaction_mode"] = "IMMEDIATE" - see https://forum.djangoproject.com/t/sqlite-and-database-is-locked-error/26994 for more information.

Quickstart

Install the django-dbtasks package from PyPI, and configure your TASKS setting as follows:

TASKS = {
    "default": {
        "BACKEND": "dbtasks.backend.DatabaseBackend",
        "OPTIONS": {
            # Set this to True to execute tasks immediately (no need for a runner).
            "immediate": False,
            # Whether to send `task_enqueued`, `task_started`, and `task_finished`.
            "signals": True,
            # How long to retain ScheduledTasks in the database. Forever if not set.
            "retain": datetime.timedelta(days=7),
            # Tasks to run periodically.
            "periodic": {
                # Runs at 3:30am every Monday through Friday.
                "myproject.tasks.maintenance": "30 3 * * 1-5",
            },
        },
    },
}

Runner

django-dbtasks includes a dedicated taskrunner management command:

usage: manage.py taskrunner [-h] [-w WORKERS] [-i WORKER_ID] [--backend BACKEND]
                            [--delay DELAY] [--no-periodic]

It is also straightforward to run the runner in a thread of its own:

runner = Runner(workers=4, worker_id="in-process")
t = threading.Thread(target=runner.run)
t.start()
...
runner.stop()
t.join()

django-dbtasks itself is tested on free-threading builds of Python 3.13 and 3.14, but compatibility will depend on your database driver and other packages.

Periodic Tasks

As shown in the quickstart, periodic tasks are specified as a mapping in the backend OPTIONS under the periodic key. The keys of the mapping should be dotted paths to the tasks, and the values should either be a string in crontab format, or an instance of dbtasks.Periodic. Using a dbtasks.Periodic allows you to specify args and kwargs (as values or callables) that will be passed to the task. For example, the Runner registers a periodic task to remove old tasks past the retention window, in a manner similar to:

# Convert the `timedelta` to seconds, so as to be JSON-serializable.
retain_secs = int(self.backend.options["retain"].total_seconds())
# Clear old tasks every hour, on a random minute.
self.periodic["dbtasks.runner.cleanup"] = Periodic("~ * * * *", args=[retain_secs])

Note that this allows you to specify a custom Periodic for the dbtasks.runner.cleanup task in your TASKS setting if necessary.

Logging

Be sure to add a dbtasks logger to your LOGGING setting:

LOGGING = {
    ...
    "loggers": {
        "dbtasks": {
            "handlers": ["console"],
            "level": "INFO",
        },
    },
}

Testing

There is a RunnerTestCase that starts a runner for the duration of a test suite. See test_tasks.py for example usage.

Extras

django-dbtasks comes with a number of optional features for integration into various environments.

dbtasks.contrib.serve

This is a Django app you can add to INSTALLED_APPS to enable a serve management command that runs your site in a Granian server, with options to also start an integrated task runner. For instance, the following command will serve your site on 127.0.0.1:8000, start a runner, and reload your server (and tasks!) on code changes:

manage.py serve -k -r

Running an integrated task runner (with -k/--tasks) is not a great idea in production, but is excellent for development. Granian is a production-caliber server, so you can also use serve in production alongside a separate taskrunner command.

You can install the django-dbtasks[serve] extra to include Granian automatically.

uWSGI mule

You can run a uWSGI mule that starts a task runner by passing --mule=dbtasks.contrib.mule:taskrunner or specifying <mule>dbtasks.contrib.mule:taskrunner</mule> in your XML config.