Celery "received unregistered task"

Question

I'm new to celery and was trying to use it in my app. Below is my basic app structure

 my_app
 |-run.py
 |-app
    |-mod1
    |-mod2
    |-tasks
       |-__init__.py
       |-email
       |-other_tasks_file

I want to confine all my background tasks to my tasks module . In the init.py of tasks i have

from celery import Celery

celery = Celery('my_app', broker='redis://localhost:6379/0')

within my tasks/email i have

from app.tasks import celery

@celery.task
def send_email():
    #do stuff

from the terminal i start a worker using

 celery -A app.tasks worker --loglevel=DEBUG

But my task does not show up in celery's task list . Also, once i run my task from the interpreter like so

>>from app.tasks import email
>>email_result = email.send_email.delay()

When i do this i get the following response in my celery terminal

Received unregistered task of type 'app.tasks.emails.send_email'.
The message has been ignored and discarded.

Did you remember to import the module containing this task?
Or maybe you are using relative imports?
Please see url for more information.

The full contents of the message body was:
{'kwargs': {}, 'taskset': None, 'id': '51e8f766-e772-4d85-bad0-5a6774ea541a', 'eta': None, 'timelimit': (None, None), 'args': [], 'retries': 0, 'task': 'app.tasks.emails.send_email', 'utc': True, 'errbacks': None, 'chord': None, 'expires': None, 'callbacks': None} (283b)
Traceback (most recent call last):
File "/usr/local/lib/python3.4/site-packages/celery/app/utils.py", line 235, in find_app
sym = symbol_by_name(app, imp=imp)
File "/usr/local/lib/python3.4/site-packages/celery/bin/base.py", line 492, in symbol_by_name
return symbol_by_name(name, imp=imp)
File "/usr/local/lib/python3.4/site-packages/kombu/utils/__init__.py", line 101, in symbol_by_name
return getattr(module, cls_name) if cls_name else module
AttributeError: 'module' object has no attribute 'tasks'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/usr/local/lib/python3.4/site-packages/celery/worker/consumer.py", line 456, in on_task_received
strategies[name](message, body,
KeyError: 'app.tasks.channels.send_email'

I am using python 3.4 and celery 3.1.23

Solution

If anyone needs it, I finally got it working . What I needed to do was run a celery worker for the actual file containing the task inorder for celery to register the task -

celery -A app.tasks.emails worker --loglevel=DEBUG  

because simply running

celery -A app.tasks worker --loglevel=DEBUG

(this is my wild guess) would not actually import my send_email() task . If anyone can give me an explanation for this please do.