celery start multiple workers and one beat as daemon crash - django

Question

i try to start multiple workers with celery multi and celery beat simultaneously.
I start the workers as daemon with this command:
celery multi start 2 -A djangoproj -Q:1 longtaskqueue -Q:2 shorttaskqueue -c:1 1 -c:2 1
Now if i start the beat as daemon with:
celery multi start -A djangoproj workerbeat1 --beat
the workers crash with this error in the log file:
[2019-11-06 13:00:51,641: WARNING/MainProcess] /usr/local/lib/python3.7/dist-packages/celery/fixups/django.py:202: 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 leak, never '
[2019-11-06 13:01:16,722: ERROR/MainProcess] Control command error: OperationalError("\nCannot route message for exchange 'reply.celery.pidbox': Table empty or key no longer exists.\nProbably the key ('_kombu.binding.reply.celery.pidbox') has been removed from the Redis database.\n")
Traceback (most recent call last):
File "/usr/local/lib/python3.7/dist-packages/kombu/connection.py", line 439, in _reraise_as_library_errors
yield
File "/usr/local/lib/python3.7/dist-packages/kombu/connection.py", line 518, in _ensured
return fun(*args, **kwargs)
File "/usr/local/lib/python3.7/dist-packages/kombu/messaging.py", line 203, in _publish
mandatory=mandatory, immediate=immediate,
File "/usr/local/lib/python3.7/dist-packages/kombu/transport/virtual/base.py", line 605, in basic_publish
message, exchange, routing_key, **kwargs
File "/usr/local/lib/python3.7/dist-packages/kombu/transport/virtual/exchange.py", line 70, in deliver
for queue in _lookup(exchange, routing_key):
File "/usr/local/lib/python3.7/dist-packages/kombu/transport/redis.py", line 877, in _lookup
exchange, redis_key))
kombu.exceptions.InconsistencyError:
Cannot route message for exchange 'reply.celery.pidbox': Table empty or key no longer exists.
Probably the key ('_kombu.binding.reply.celery.pidbox') has been removed from the Redis database.
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/local/lib/python3.7/dist-packages/celery/worker/pidbox.py", line 46, in on_message
self.node.handle_message(body, message)
File "/usr/local/lib/python3.7/dist-packages/kombu/pidbox.py", line 145, in handle_message
return self.dispatch(**body)
File "/usr/local/lib/python3.7/dist-packages/kombu/pidbox.py", line 115, in dispatch
ticket=ticket)
File "/usr/local/lib/python3.7/dist-packages/kombu/pidbox.py", line 151, in reply
serializer=self.mailbox.serializer)
File "/usr/local/lib/python3.7/dist-packages/kombu/pidbox.py", line 285, in _publish_reply
**opts
File "/usr/local/lib/python3.7/dist-packages/kombu/messaging.py", line 181, in publish
exchange_name, declare,
File "/usr/local/lib/python3.7/dist-packages/kombu/connection.py", line 551, in _ensured
errback and errback(exc, 0)
File "/usr/lib/python3.7/contextlib.py", line 130, in __exit__
self.gen.throw(type, value, traceback)
File "/usr/local/lib/python3.7/dist-packages/kombu/connection.py", line 444, in _reraise_as_library_errors
sys.exc_info()[2])
File "/usr/local/lib/python3.7/dist-packages/vine/five.py", line 194, in reraise
raise value.with_traceback(tb)
File "/usr/local/lib/python3.7/dist-packages/kombu/connection.py", line 439, in _reraise_as_library_errors
yield
File "/usr/local/lib/python3.7/dist-packages/kombu/connection.py", line 518, in _ensured
return fun(*args, **kwargs)
File "/usr/local/lib/python3.7/dist-packages/kombu/messaging.py", line 203, in _publish
mandatory=mandatory, immediate=immediate,
File "/usr/local/lib/python3.7/dist-packages/kombu/transport/virtual/base.py", line 605, in basic_publish
message, exchange, routing_key, **kwargs
File "/usr/local/lib/python3.7/dist-packages/kombu/transport/virtual/exchange.py", line 70, in deliver
for queue in _lookup(exchange, routing_key):
File "/usr/local/lib/python3.7/dist-packages/kombu/transport/redis.py", line 877, in _lookup
exchange, redis_key))
kombu.exceptions.OperationalError:
Cannot route message for exchange 'reply.celery.pidbox': Table empty or key no longer exists.
Probably the key ('_kombu.binding.reply.celery.pidbox') has been removed from the Redis database.
My celery config in django looks like this:
djangoproj/djangoproj/settings.py:
CELERY_BROKER_URL = 'redis://localhost:6379'
CELERY_RESULT_BACKEND = 'redis://localhost:6379'
CELERY_ACCEPT_CONTENT = ['application/json']
CELERY_RESULT_SERIALIZER = 'json'
CELERY_TASK_SERIALIZER = 'json'
CELERY_TIMEZONE = 'Europe/Berlin'
CELERY_TASK_QUEUES = (
Queue('shorttaskqueue', Exchange('shorttaskqueue'), routing_key='shorttaskqueue'),
Queue('longtaskqueue', Exchange('longtaskqueue'), routing_key='longtaskqueue'),
)
CELERY_ROUTES = {
'api.tasks.shorttaskqueue': {'queue': 'shorttaskqueue'},
'api.tasks.longtaskqueue': {'queue': 'longtaskqueue'},
}
I use Redis 5.0.3, Django 2.2.3 and Celery 4.3.0.
Why it crashes and is there a way to start one beat and multiple workers with one command?
Thanks for help!