Background tasks and scheduled jobs

Your deployment runs a web process: uvicorn (or gunicorn) serving your Django app. Anything that runs inside that process, such as a thread or a scheduler started at import time, stops when the container restarts and runs once per instance.

Caution

DjangoCloud deploys one web service per project. Running a separate Celery worker or scheduler as part of the same project isn’t something it sets up for you today.

What works today

• Short work inside a request. Anything that finishes while the user waits.
• Work triggered from outside. For example a scheduled GitHub Action, or an external cron service calling a protected URL in your app that does the work.
• Work in another service. Run your worker where you like, for example as a second Lightsail container service in your own AWS account, using the same image and the same DATABASE_URL and broker settings.

Tips

• Make jobs idempotent. With more than one instance, or after a restart, the same job can be triggered twice.
• Don’t rely on local disk to pass data between a request and a job. See the ephemeral container.
• Keep the broker (such as Redis) outside the container.