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Version:	2.8.1
Web:	http://django-celery-beat.readthedocs.io/
Download:	http://pypi.python.org/pypi/django-celery-beat
Source:	http://github.com/celery/django-celery-beat
DeepWiki:
Keywords:	django, celery, beat, periodic task, cron, scheduling

This extension enables you to store the periodic task schedule in thedatabase.

The periodic tasks can be managed from the Django Admin interface, where youcan create, edit and delete periodic tasks and how often they should run.

Usage and installation instructions for this extension are availablefrom theCelery documentation.

>>>fromdjango_celery_beat.modelsimportPeriodicTask,PeriodicTasks>>>PeriodicTask.objects.all().update(last_run_at=None)>>>PeriodicTasks.update_changed()

• django_celery_beat.models.PeriodicTask

This model defines a single periodic task to be run.

It must be associated with a schedule, which defines how often the task shouldrun.

• django_celery_beat.models.IntervalSchedule

A schedule that runs at a specific interval (e.g. every 5 seconds).

• django_celery_beat.models.CrontabSchedule

A schedule with fields like entries in cron:minute hour day-of-week day_of_month month_of_year.

• django_celery_beat.models.PeriodicTasks

This model is only used as an index to keep track of when the schedule haschanged.

Whenever you update aPeriodicTask a counter in this table is alsoincremented, which tells thecelery beat service to reload the schedulefrom the database.

If you update periodic tasks in bulk, you will need to update the countermanually:

>>>fromdjango_celery_beat.modelsimportPeriodicTasks>>>PeriodicTasks.update_changed()

To create a periodic task executing at an interval you must firstcreate the interval object:

>>>fromdjango_celery_beat.modelsimportPeriodicTask,IntervalSchedule# executes every 10 seconds.>>>schedule,created=IntervalSchedule.objects.get_or_create(...every=10,...period=IntervalSchedule.SECONDS,... )

That's all the fields you need: a period type and the frequency.

You can choose between a specific set of periods:

• IntervalSchedule.DAYS
• IntervalSchedule.HOURS
• IntervalSchedule.MINUTES
• IntervalSchedule.SECONDS
• IntervalSchedule.MICROSECONDS

There's also a "choices tuple" available should you need to present thisto the user:

>>>IntervalSchedule.PERIOD_CHOICES

Now that we have defined the schedule object, we can create the periodic taskentry:

>>>PeriodicTask.objects.create(...interval=schedule,# we created this above....name='Importing contacts',# simply describes this periodic task....task='proj.tasks.import_contacts',# name of task.... )

Note that this is a very basic example, you can also specify the argumentsand keyword arguments used to execute the task, thequeue to send itto[*], and set an expiry time.

Here's an example specifying the arguments, note how JSON serialization isrequired:

>>>importjson>>>fromdatetimeimportdatetime,timedelta>>>PeriodicTask.objects.create(...interval=schedule,# we created this above....name='Importing contacts',# simply describes this periodic task....task='proj.tasks.import_contacts',# name of task....args=json.dumps(['arg1','arg2']),...kwargs=json.dumps({...'be_careful':True,...     }),...expires=datetime.utcnow()+timedelta(seconds=30)... )

A crontab schedule has the fields:minute,hour,day_of_week,day_of_month andmonth_of_year, so if you want the equivalentof a30 * * * * (execute 30 minutes past every hour) crontab entry you specify:

>>>fromdjango_celery_beat.modelsimportCrontabSchedule,PeriodicTask>>>schedule,_=CrontabSchedule.objects.get_or_create(...minute='30',...hour='*',...day_of_week='*',...day_of_month='*',...month_of_year='*',...timezone=zoneinfo.ZoneInfo('Canada/Pacific')... )

The crontab schedule is linked to a specific timezone using the 'timezone' input parameter.

Then to create a periodic task using this schedule, use the same approach asthe interval-based periodic task earlier in this document, but insteadofinterval=schedule, specifycrontab=schedule:

>>>PeriodicTask.objects.create(...crontab=schedule,...name='Importing contacts',...task='proj.tasks.import_contacts',... )

You can use theenabled flag to temporarily disable a periodic task:

>>>periodic_task.enabled=False>>>periodic_task.save()

The periodic tasks still need 'workers' to execute them.So make sure the defaultCelery package is installed.(If not installed, please follow the installation instructionshere:https://github.com/celery/celery)

Both the worker and beat services need to be running at the same time.

1. Start a Celery worker service (specify your Django project name):

   $ celery -A [project-name] worker --loglevel=info

2. As a separate process, start the beat service (specify the Django scheduler):

   $ celery -A [project-name] beat -l info --scheduler django_celery_beat.schedulers:DatabaseScheduler

   OR you can use the -S (scheduler flag), for more options seecelery beat --help):

   $ celery -A [project-name] beat -l info -S django

   Also, as an alternative, you can run the two steps above (worker and beat services)with only one command (recommended fordevelopment environment only):

   $ celery -A [project-name] worker --beat --scheduler django --loglevel=info

3. Now you can add and manage your periodic tasks from the Django Admin interface.

You can install django-celery-beat either via the Python Package Index (PyPI)or from source.

To install usingpip:

$ pip install --upgrade django-celery-beat

Download the latest version of django-celery-beat fromhttp://pypi.python.org/pypi/django-celery-beat

You can install it by doing the following :

$ python3 -m venv .venv$source .venv/bin/activate$ pip install --upgrade build pip$ tar xvfz django-celery-beat-0.0.0.tar.gz$cd django-celery-beat-0.0.0$ python -m build$ pip install --upgrade.

After installation, adddjango_celery_beat to Django's settings module:

INSTALLED_APPS= [    ...,'django_celery_beat',]

Run thedjango_celery_beat migrations using:

$ python manage.py migrate django_celery_beat

You can install the latest main version of django-celery-beat using the followingpip command:

$ pip install git+https://github.com/celery/django-celery-beat#egg=django-celery-beat

To spin up a local development copy of django-celery-beat with Django admin athttp://127.0.0.1:58000/admin/ run:

$ docker-compose up --build

Log-in as useradmin with passwordadmin.

If you have a project that is time zone naive, you can setDJANGO_CELERY_BEAT_TZ_AWARE=False in your settings file.

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