django-celery PeriodicTask and eta field - celery

Question

I have a django project in combination with celery and my need is to be able to schedule tasks dynamically, at some point in the future, with recurrence or not. I need the ability to delete/edit already scheduled tasks
So to achieve this at the beginning I started using django-celery with DatabaseScheduler to store some PeriodicTasks (with expiration) to the database as it is described more or less here
In this way if I close my app and start it again my schedules are still there
My problem though still remains since I cannot utilize the eta and schedule a task at some point in the future. Is it possible somehow to dynamically schedule a task with eta?
A second question of mine is whether I can schedule a once off task, like schedule it to run e.g. at 2015-05-15 15:50:00 (that is why I'm trying to use eta)
Finally, I will be scheduling some thousants of notifications, is celery beat capable to handle this number of scheduled tasks? some of them once-off while others being periodic? Or do I have to go with a more advanced solution such as APScheduler
Thank you

Answer 1

I've faced the same problem yesterday. My ugly temporary solution is:
# tasks.py
from djcelery.models import PeriodicTask, IntervalSchedule
from datetime import timedelta, datetime
from django.utils.timezone import now
...
#app.task
def schedule_periodic_task(task='app.tasks.task', task_args=[], task_kwargs={},
interval=(1, 'minute'), expires=now()+timedelta(days=365*100)):
PeriodicTask.objects.filter(name=task+str(task_args)+str(task_kwargs)).delete()
task = PeriodicTask.objects.create(
name=task+str(task_args)+str(task_kwargs), task=task,
args=str(task_args),
kwargs=str(task_kwargs),
interval=IntervalSchedule.objects.get_or_create(
every=interval[0],
period=interval[1])[0],
expires=expires,
)
task.save()
So, if you want to schedule periodic task with eta, you shoud
# anywhere.py
schedule_periodic_task.apply_async(
kwargs={'task': 'grabber.tasks.grab_events',
'task_args': [instance.xbet_id], 'task_kwargs': {},
'interval': (10, 'seconds'),
'expires': instance.start + timedelta(hours=3)},
eta=instance.start,
)
schedule task with eta, which creates periodic task. Ugly:
deal with raw.task.name
strange period (n, 'interval')
Please, let me know, if you designed some pretty solution.