{"action":"created","issue":{"url":"https://api.github.com/repos/celery/celery/issues/2757","labels_url":"https://api.github.com/repos/celery/celery/issues/2757/labels{/name}","comments_url":"https://api.github.com/repos/celery/celery/issues/2757/comments","events_url":"https://api.github.com/repos/celery/celery/issues/2757/events","html_url":"https://github.com/celery/celery/issues/2757","id":100288933,"number":2757,"title":"Celery Channel Error 406 with RabbitMQ","user":{"login":"nguyenhoan1988","id":2057220,"avatar_url":"https://avatars.githubusercontent.com/u/2057220?v=3","gravatar_id":"","url":"https://api.github.com/users/nguyenhoan1988","html_url":"https://github.com/nguyenhoan1988","followers_url":"https://api.github.com/users/nguyenhoan1988/followers","following_url":"https://api.github.com/users/nguyenhoan1988/following{/other_user}","gists_url":"https://api.github.com/users/nguyenhoan1988/gists{/gist_id}","starred_url":"https://api.github.com/users/nguyenhoan1988/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/nguyenhoan1988/subscriptions","organizations_url":"https://api.github.com/users/nguyenhoan1988/orgs","repos_url":"https://api.github.com/users/nguyenhoan1988/repos","events_url":"https://api.github.com/users/nguyenhoan1988/events{/privacy}","received_events_url":"https://api.github.com/users/nguyenhoan1988/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2015-08-11T11:08:20Z","updated_at":"2015-08-11T11:09:37Z","closed_at":null,"body":"I am using Celery workflow to generate a complex workflow with combination of chord, chain, group together.\r\n\r\nThen I keep running to this problem below, if I run multiple workers, multiple threads, I will hit this problem faster and my workers keep being killed.\r\n\r\nI use **Redis** as result backend, and **RabbitMQ** as broker.\r\n\r\n```\r\n[2015-08-11 10:49:11,613: ERROR/MainProcess] Unrecoverable error: ChannelError('channel error 406, message: PRECONDITION_FAILED - unknown delivery tag 2039',)\r\nTraceback (most recent call last):\r\n  File \"/myUser/anaconda/lib/python2.7/site-packages/celery/worker/__init__.py\", line 206, in start\r\n    self.blueprint.start(self)\r\n  File \"/myUser/anaconda/lib/python2.7/site-packages/celery/bootsteps.py\", line 123, in start\r\n    step.start(parent)\r\n  File \"/myUser/anaconda/lib/python2.7/site-packages/celery/bootsteps.py\", line 374, in start\r\n    return self.obj.start()\r\n  File \"/myUser/anaconda/lib/python2.7/site-packages/celery/worker/consumer.py\", line 278, in start\r\n    blueprint.start(self)\r\n  File \"/myUser/anaconda/lib/python2.7/site-packages/celery/bootsteps.py\", line 123, in start\r\n    step.start(parent)\r\n  File \"/myUser/anaconda/lib/python2.7/site-packages/celery/worker/consumer.py\", line 821, in start\r\n    c.loop(*c.loop_args())\r\n  File \"/myUser/anaconda/lib/python2.7/site-packages/celery/worker/loops.py\", line 70, in asynloop\r\n    next(loop)\r\n  File \"/myUser/anaconda/lib/python2.7/site-packages/kombu/async/hub.py\", line 324, in create_loop\r\n    cb(*cbargs)\r\n  File \"/myUser/anaconda/lib/python2.7/site-packages/kombu/transport/base.py\", line 162, in on_readable\r\n    reader(loop)\r\n  File \"/myUser/anaconda/lib/python2.7/site-packages/kombu/transport/base.py\", line 144, in _read\r\n    drain_events(timeout=0)\r\n  File \"/myUser/anaconda/lib/python2.7/site-packages/librabbitmq/__init__.py\", line 220, in drain_events\r\n    self._basic_recv(timeout)\r\nChannelError: channel error 406, message: PRECONDITION_FAILED - unknown delivery tag 2039\r\n```"},"comment":{"url":"https://api.github.com/repos/celery/celery/issues/comments/129836667","html_url":"https://github.com/celery/celery/issues/2757#issuecomment-129836667","issue_url":"https://api.github.com/repos/celery/celery/issues/2757","id":129836667,"user":{"login":"nguyenhoan1988","id":2057220,"avatar_url":"https://avatars.githubusercontent.com/u/2057220?v=3","gravatar_id":"","url":"https://api.github.com/users/nguyenhoan1988","html_url":"https://github.com/nguyenhoan1988","followers_url":"https://api.github.com/users/nguyenhoan1988/followers","following_url":"https://api.github.com/users/nguyenhoan1988/following{/other_user}","gists_url":"https://api.github.com/users/nguyenhoan1988/gists{/gist_id}","starred_url":"https://api.github.com/users/nguyenhoan1988/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/nguyenhoan1988/subscriptions","organizations_url":"https://api.github.com/users/nguyenhoan1988/orgs","repos_url":"https://api.github.com/users/nguyenhoan1988/repos","events_url":"https://api.github.com/users/nguyenhoan1988/events{/privacy}","received_events_url":"https://api.github.com/users/nguyenhoan1988/received_events","type":"User","site_admin":false},"created_at":"2015-08-11T11:09:37Z","updated_at":"2015-08-11T11:09:37Z","body":"I have tried with the default Python rabbitmq client and the **librabbitmq** library and still get the same issue."}}