Django & Celery: How do I schedule a job to run only once using Celery(similar to "at" command in linux)?

Question

I looked at django-celery tutorial and I think it will really help me running the background tasks without letting the users to wait. However, I have a specific requirement in the program such that when user enters a date, django should be able to do the scheduling and defer the execution to a later time. I have used at program before but it gives a lot of permission issues. But when I read the documentation for Celery, I can only see that Celery supports cron like tasks called @periodic_task. I'm sure that it also provides at like mechanism, but I couldn't find any documentation. Can anybody point me to some resources or simply tell me how to achieve that? Thanks.

Answer 1

The docs state that you can schedule tasks to execute at a specific time, using the eta argument.

Answer 2

You can supply the countdown or ETA argument to the apply_async() function. By doing so, you can define the earliest time that the task is gonna be executed, but not the exact one (it depends on your queue). For more details see here.