Comment 12 for bug 1695746

I test newton 5.10.2, and in ceilometer agent notification, the log shows
2017-10-21 03:33:19.779 225636 ERROR root [-] Unexpected exception occurred 60 time(s)... retrying.
2017-10-21 03:33:19.779 225636 ERROR root Traceback (most recent call last):
2017-10-21 03:33:19.779 225636 ERROR root File "/usr/lib/python2.7/site-packages/oslo_utils/excutils.py", line 250, in wrapper
2017-10-21 03:33:19.779 225636 ERROR root return infunc(*args, **kwargs)
2017-10-21 03:33:19.779 225636 ERROR root File "/usr/lib/python2.7/site-packages/oslo_messaging/_drivers/base.py", line 203, in _runner
2017-10-21 03:33:19.779 225636 ERROR root batch_size=self.batch_size, batch_timeout=self.batch_timeout)
2017-10-21 03:33:19.779 225636 ERROR root File "/usr/lib/python2.7/site-packages/oslo_messaging/_drivers/base.py", line 52, in wrapper
2017-10-21 03:33:19.779 225636 ERROR root msg = func(in_self, timeout=timeout_watch.leftover(True))
2017-10-21 03:33:19.779 225636 ERROR root File "/usr/lib/python2.7/site-packages/oslo_messaging/_drivers/amqpdriver.py", line 286, in poll
2017-10-21 03:33:19.779 225636 ERROR root self._message_operations_handler.process()
2017-10-21 03:33:19.779 225636 ERROR root File "/usr/lib/python2.7/site-packages/oslo_messaging/_drivers/amqpdriver.py", line 89, in process
2017-10-21 03:33:19.779 225636 ERROR root task()
2017-10-21 03:33:19.779 225636 ERROR root File "/usr/lib/python2.7/site-packages/oslo_messaging/_drivers/impl_rabbit.py", line 251, in acknowledge
2017-10-21 03:33:19.779 225636 ERROR root self._raw_message.ack()
2017-10-21 03:33:19.779 225636 ERROR root File "/usr/lib/python2.7/site-packages/kombu/message.py", line 88, in ack
2017-10-21 03:33:19.779 225636 ERROR root self.channel.basic_ack(self.delivery_tag)
2017-10-21 03:33:19.779 225636 ERROR root File "/usr/lib/python2.7/site-packages/amqp/channel.py", line 1583, in basic_ack
2017-10-21 03:33:19.779 225636 ERROR root self._send_method((60, 80), args)
2017-10-21 03:33:19.779 225636 ERROR root File "/usr/lib/python2.7/site-packages/amqp/abstract_channel.py", line 50, in _send_method
2017-10-21 03:33:19.779 225636 ERROR root raise RecoverableConnectionError('connection already closed')
2017-10-21 03:33:19.779 225636 ERROR root RecoverableConnectionError: connection already closed