Hướng dẫn openstack lost connection to mysql server during query - openstack bị mất kết nối với máy chủ mysql trong khi truy vấn

Charms 18.05, Xenial and upgrading from Pike to Queens.

We ran the steps in https://docs.openstack.org/project-deploy-guide/charm-deployment-guide/latest/app-upgrade-openstack.html to upgrade.

After the upgrade, the logs were filled with mysql errors after any operation using the database:

2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines [-] Database connection was found disconnected; reconnecting: DBConnectionError: (pymysql.err.OperationalError) (2013, 'Lost connection to MySQL server during query') [SQL: u'SELECT 1']
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines Traceback (most recent call last):
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines File "/usr/lib/python2.7/dist-packages/oslo_db/sqlalchemy/engines.py", line 73, in _connect_ping_listener
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines connection.scalar(select([1]))
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 877, in scalar
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines return self.execute(object, *multiparams, **params).scalar()
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 945, in execute
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines return meth(self, multiparams, params)
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines File "/usr/lib/python2.7/dist-packages/sqlalchemy/sql/elements.py", line 263, in _execute_on_connection
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines return connection._execute_clauseelement(self, multiparams, params)
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1053, in _execute_clauseelement
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines compiled_sql, distilled_params
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1189, in _execute_context
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines context)
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1398, in _handle_dbapi_exception
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines util.raise_from_cause(newraise, exc_info)
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines File "/usr/lib/python2.7/dist-packages/sqlalchemy/util/compat.py", line 203, in raise_from_cause
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines reraise(type(exception), exception, tb=exc_tb, cause=cause)
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1182, in _execute_context
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines context)
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/default.py", line 470, in do_execute
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines cursor.execute(statement, parameters)
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines File "/usr/lib/python2.7/dist-packages/pymysql/cursors.py", line 165, in execute
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines result = self._query(query)
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines File "/usr/lib/python2.7/dist-packages/pymysql/cursors.py", line 321, in _query
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines conn.query(q)
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines File "/usr/lib/python2.7/dist-packages/pymysql/connections.py", line 860, in query
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines self._affected_rows = self._read_query_result(unbuffered=unbuffered)
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines File "/usr/lib/python2.7/dist-packages/pymysql/connections.py", line 1061, in _read_query_result
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines result.read()
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines File "/usr/lib/python2.7/dist-packages/pymysql/connections.py", line 1349, in read
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines first_packet = self.connection._read_packet()
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines File "/usr/lib/python2.7/dist-packages/pymysql/connections.py", line 991, in _read_packet
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines packet_header = self._read_bytes(4)
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines File "/usr/lib/python2.7/dist-packages/pymysql/connections.py", line 1037, in _read_bytes
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines CR.CR_SERVER_LOST, "Lost connection to MySQL server during query")
2018-06-28 05:34:16.223 84669 ERROR oslo_db.sqlalchemy.engines DBConnectionError: (pymysql.err.OperationalError) (2013, 'Lost connection to MySQL server during query') [SQL: u'SELECT 1']