How to implement autoretry for Celery tasks

Question

In Celery, you can retry any task in case of exception. You can do it like so:

@task(max_retries=5)
def div(a, b):
    try:
        return a / b
    except ZeroDivisionError, exc:
        raise div.retry(exc=exc)

In this case, if you want to to divide by zero, task will be retied five times. But you have to check for errors in you code explicitly. Task will not be retied if you skip try-except block.

I want my functions to look like:

@celery.task(autoretry_on=ZeroDivisionError, max_retries=5)
def div(a, b):
    return a / b

Answer 1

Celery (since version 4.0) has exactly what you were looking for:

@app.task(autoretry_for=(SomeException,))
def my_task():
    ...

See: http://docs.celeryproject.org/en/latest/userguide/tasks.html#automatic-retry-for-known-exceptions