AttributeError: 'DisabledBackend' object has no attribute '_get_task_meta_for'

[ralfeus]

I use RabbitMQ as a message broker, for which as far as I understand RPC backend can be used. If I specify CELERY_RESULT_BACKEND = 'rpc://' and try to get result I gen an error:

Traceback (most recent call last): File "/var/www/order/lib/python3.6/site-packages/flask/app.py", line 2464, in call return self.wsgi_app(environ, start_response) File "/var/www/order/lib/python3.6/site-packages/flask/app.py", line 2450, in wsgi_app response = self.handle_exception(e) File "/var/www/order/lib/python3.6/site-packages/flask/app.py", line 1867, in handle_exception reraise(exc_type, exc_value, tb) File "/var/www/order/lib/python3.6/site-packages/flask/_compat.py", line 39, in reraise raise value File "/var/www/order/lib/python3.6/site-packages/flask/app.py", line 2447, in wsgi_app response = self.full_dispatch_request() File "/var/www/order/lib/python3.6/site-packages/flask/app.py", line 1952, in full_dispatch_request rv = self.handle_user_exception(e) File "/var/www/order/lib/python3.6/site-packages/flask/app.py", line 1821, in handle_user_exception reraise(exc_type, exc_value, tb) File "/var/www/order/lib/python3.6/site-packages/flask/_compat.py", line 39, in reraise raise value File "/var/www/order/lib/python3.6/site-packages/flask/app.py", line 1950, in full_dispatch_request rv = self.dispatch_request() File "/var/www/order/lib/python3.6/site-packages/flask_debugtoolbar/init.py", line 125, in dispatch_request return view_func(**req.view_args) File "/var/www/order/app/routes/client.py", line 111, in test result = {'state': task.state} File "/var/www/order/lib/python3.6/site-packages/flask_execute/futures.py", line 32, in getattr return getattr(self.proxy, key) File "/var/www/order/lib/python3.6/site-packages/celery/result.py", line 477, in state return self._get_task_meta()['status'] File "/var/www/order/lib/python3.6/site-packages/celery/result.py", line 416, in _get_task_meta return self._maybe_set_cache(self.backend.get_task_meta(self.id)) File "/var/www/order/lib/python3.6/site-packages/celery/backends/base.py", line 519, in get_task_meta meta = self._get_task_meta_for(task_id) AttributeError: 'DisabledBackend' object has no attribute '_get_task_meta_for'

I read this error occurs when no backend is specified. So I've ensured it is. If I start celery manually I get this:

(order) ralfeus@sandlet /v/w/order> celery -A flask_execute.ext.celery worker INFO:app:<class 'app.config.Config'> INFO:app:None INFO:app:Blueprints are registered

-------------- celery@sandlet v5.0.1 (singularity) --- * ----- -- *** ---- Linux-5.4.0-51-generic-x86_64-with-Ubuntu-18.04-bionic 2020-10-19 14:08:14

• ** --- ---
• ** ---------- [config]
• ** ---------- .> app: app:0x7fa63503f198
• ---------- .> transport: amqp://guest:@localhost:5672//
• ---------- .> results: rpc://**
• --- --- .> concurrency: 4 (prefork) -- **** ---- .> task events: OFF (enable -E to monitor tasks in this worker) --- ----- -------------- [queues] .> celery exchange=celery(direct) key=celery

So it's obvious the results backend is registered. Same happens when I specify Redis as a message broker and a result backend.

[bprinty]

Thanks for the heads up! I'll try to reproduce this locally and let you know what I find.

[bprinty]

Can you post the part of your app config that contains the CELERY... variables and how you're setting up the plugin in your app? I'm not having issues locally using a different backend. Thanks!