ModelError: 'NoneType' object has no attribute 'closed'

[evgenkisel]

We use the Gofer as a part of the Katello installation.

Sometimes on many boxes I see the exception:

`
Oct 30 09:33:36 example.host goferd: [INFO][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.connect:28 - connecting: proton+amqps://foreman-proxy.pac.nhl.com:5647
Oct 30 09:33:36 example.host goferd: [INFO][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.connect:30 - connected: proton+amqps://foreman-proxy.pac.nhl.com:5647
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 - 'NoneType' object has no attribute 'closed'
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 - Traceback (most recent call last):
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -   File "/usr/lib/python2.7/site-packages/gofer/messaging/adapter/model.py", line 40, in _fn
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -     return fn(*args, **keywords)
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -   File "/usr/lib/python2.7/site-packages/gofer/messaging/adapter/model.py", line 584, in open
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -     self._impl.open()
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -   File "/usr/lib/python2.7/site-packages/gofer/messaging/adapter/proton/reliability.py", line 45, in _fn
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -     return fn(messenger, *args, **kwargs)
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -   File "/usr/lib/python2.7/site-packages/gofer/messaging/adapter/proton/consumer.py", line 73, in open
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -     self.receiver = self.connection.receiver(self.node.address)
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -   File "/usr/lib/python2.7/site-packages/gofer/messaging/adapter/proton/connection.py", line 121, in receiver
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -     return self._impl.create_receiver(address, name=name, dynamic=dynamic, options=options)
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -   File "/usr/lib64/python2.7/site-packages/proton/_utils.py", line 415, in create_receiver
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -     options=options), fetcher, credit=prefetch)
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -   File "/usr/lib64/python2.7/site-packages/proton/_utils.py", line 202, in __init__
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -     super(BlockingReceiver, self).__init__(connection, receiver)
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -   File "/usr/lib64/python2.7/site-packages/proton/_utils.py", line 41, in __init__
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -     msg="Opening link %s" % link.name)
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -   File "/usr/lib64/python2.7/site-packages/proton/_utils.py", line 475, in wait
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -     self.container.process()
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -   File "/usr/lib64/python2.7/site-packages/proton/_reactor.py", line 239, in process
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -     event.dispatch(self._global_handler)
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -   File "/usr/lib64/python2.7/site-packages/proton/_events.py", line 162, in dispatch
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -     _dispatch(handler, type.method, self)
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -   File "/usr/lib64/python2.7/site-packages/proton/_events.py", line 125, in _dispatch
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -     handler.on_unhandled(method, *args)
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -   File "/usr/lib64/python2.7/site-packages/proton/_reactor.py", line 856, in on_unhandled
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -     event.dispatch(self.base)
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -   File "/usr/lib64/python2.7/site-packages/proton/_events.py", line 162, in dispatch
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -     _dispatch(handler, type.method, self)
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -   File "/usr/lib64/python2.7/site-packages/proton/_events.py", line 123, in _dispatch
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -     m(*args)
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -   File "/usr/lib64/python2.7/site-packages/proton/_handlers.py", line 1292, in on_selectable_expired
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -     self.update(t, s, r.now)
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -   File "/usr/lib64/python2.7/site-packages/proton/_handlers.py", line 1351, in update
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 -     if transport.closed:
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.adapter.model:44 - AttributeError: 'NoneType' object has no attribute 'closed'
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.consumer:79 - pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.consumer:79 - Traceback (most recent call last):
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.consumer:79 -   File "/usr/lib/python2.7/site-packages/gofer/messaging/consumer.py", line 72, in open
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.consumer:79 -     self.reader.open()
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.consumer:79 -   File "/usr/lib/python2.7/site-packages/gofer/messaging/adapter/model.py", line 45, in _fn
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.consumer:79 -     raise ModelError(*e.args)
Oct 30 09:33:36 example.host goferd: [ERROR][pulp.agent.2777c01c-ef54-4937-aaff-0aafaacd9693] gofer.messaging.consumer:79 - ModelError: 'NoneType' object has no attribute 'closed'

CentOS Linux release 7.8.2003 (Core)
-----
gofer.noarch                    2.12.5-3.el7               @foreman
python-gofer.noarch             2.12.5-3.el7               @foreman
python-gofer-proton.noarch      2.12.5-3.el7               @foreman
-----
python-gofer-proton.noarch      2.12.5-3.el7               @foreman
python2-qpid-proton.x86_64      0.31.0-3.el7               @epel-7
qpid-proton-c.x86_64            0.31.0-3.el7               @epel-7