Celery receives tasks from rabbitmq, but not executing them - django

Question

I have a Django project and have setup Celery + RabbitMQ to do heavy tasks asynchronously. When I call the task, RabbitMQ admin shows the task, Celery prints that the task is received, but the task is not executed.
Here is the task's code:
#app.task
def dummy_task():
print("I'm Here")
User.objects.create(username="User1")
return "User1 Created!"
In this view I send the task to celery:
def task_view(request):
result = dummy_task.delay()
return render(request, 'display_progress.html', context={'task_id': result.task_id})
I run celery with this command:
$ celery -A proj worker -l info --concurrency=2 --without-gossip
This is output of running Celery:
-------------- celery#DESKTOP-8CHJOEG v5.2.7 (dawn-chorus)
--- ***** -----
-- ******* ---- Windows-10-10.0.19044-SP0 2022-08-22 10:10:04
*** --- * ---
** ---------- [config]
** ---------- .> app: proj:0x23322847880
** ---------- .> transport: amqp://navid:**#localhost:5672//
** ---------- .> results:
*** --- * --- .> concurrency: 2 (prefork)
-- ******* ---- .> task events: OFF (enable -E to monitor tasks in this worker)
--- ***** ----- -------------- [queues]
.> celery exchange=celery(direct) key=celery
[tasks] .proj.celery.debug_task .
entitymatching.tasks.create_and_learn_machine .
entitymatching.tasks.dummy_task
[2022-08-22 10:10:04,068: INFO/MainProcess] Connected to
amqp://navid:**#127.0.0.1:5672// [2022-08-22 10:10:04,096:
INFO/MainProcess] mingle: searching for neighbors [2022-08-22
10:10:04,334: INFO/SpawnPoolWorker-1] child process 6864 calling
self.run() [2022-08-22 10:10:04,335: INFO/SpawnPoolWorker-2] child
process 12420 calling self.run() [2022-08-22 10:10:05,134:
INFO/MainProcess] mingle: all alone [2022-08-22 10:10:05,142:
WARNING/MainProcess]
C:\Users\Navid\PycharmProjects\proj\venv\lib\site-packages\celery\fixups\django.py:203:
UserWarning: Using settings.DEBUG leads to a memory
leak, never use this setting in production environments! warnings.warn('''Using settings.DEBUG leads to a memory
[2022-08-22 10:10:05,142: INFO/MainProcess] celery#DESKTOP-8CHJOEG
ready. [2022-08-22 10:10:05,143: INFO/MainProcess] Task
entitymatching.tasks.dummy_task[97f8a2eb-0006-4d53-ba6a-7b9f8649c84a]
received [2022-08-22 10:10:05,144: INFO/MainProcess] Task
entitymatching.tasks.dummy_task[17190479-0784-46b1-8dc6-870ead41e9c6]
received [2022-08-22 10:11:36,384: INFO/MainProcess] Task
proj.celery.debug_task[af3d633f-7b9a-4441-b375-9ce217a40ab3]
received
But "I'm Here" is not printed, and User1 is not created.
RabbitMQ shows that there are 3 "unack" messages in the queue:

Answer 1

You did not provide enough info although I think you have problem with your worker pools.
try adding
--pool=solo
at the end of your run command.
it will be like
celery -A proj worker -l info --concurrency=2 --without-gossip --pool=solo
although on production I recommend using gevent as your pool.
celery -A proj worker -l info --concurrency=2 --without-gossip --pool=gevent