In Juno, the error is 


<class 'heatclient.exc.HTTPInternalServerError'>: ERROR: Remote error: DBConnectionError (OperationalError) (2006, 'MySQL server has gone away') 'SELECT stack.status_reason AS stack_status_reason, stack.created_at AS stack_created_at, stack.deleted_at AS stack_deleted_at, stack.action AS stack_action, stack.status AS stack_status, stack.id AS stack_id, stack.name AS stack_name, stack.raw_template_id AS stack_raw_template_id, stack.username AS stack_username, stack.tenant AS stack_tenant, stack.parameters AS stack_parameters, stack.user_creds_id AS stack_user_creds_id, stack.owner_id AS stack_owner_id, stack.timeout AS stack_timeout, stack.disable_rollback AS stack_disable_rollback, stack.stack_user_project_id AS stack_stack_user_project_id, stack.backup AS stack_backup, stack.updated_at AS stack_updated_at \nFROM stack \nWHERE stack.deleted_at IS NULL AND stack.owner_id IS NULL AND stack.tenant = %s ORDER BY stack.created_at DESC, stack.id DESC' ('137b98f5d1974edb81700d97a4c423b0',)

[u'Traceback (most recent call last):\n', u'  File "/usr/lib/python2.7/dist-packages/oslo/messaging/rpc/dispatcher.py", line 134, in _dispatch_and_reply\n    incoming.message))\n', u'  File "/usr/lib/python2.7/dist-packages/oslo/messaging/rpc/dispatcher.py", line 177, in _dispatch\n    return self._do_dispatch(endpoint, method, ctxt, args)\n', u'  File "/usr/lib/python2.7/dist-packages/oslo/messaging/rpc/dispatcher.py", line 123, in _do_dispatch\n    result = getattr(endpoint, method)(ctxt, **new_args)\n', u'  File "/usr/lib/python2.7/dist-packages/heat/engine/service.py", line 69, in wrapped\n    return func(self, ctx, *args, **kwargs)\n', u'  File "/usr/lib/python2.7/dist-packages/heat/engine/service.py", line 499, in list_stacks\n    return [api.format_stack(stack) for stack in stacks]\n', u'  File "/usr/lib/python2.7/dist-packages/heat/engine/stack.py", line 268, in load_all\n    show_deleted, show_nested) or []\n', u'  File "/usr/lib/python2.7/dist-packages/heat/db/api.py", line 130, in stack_get_all\n    show_deleted, show_nested)\n', u'  File "/usr/lib/python2.7/dist-packages/heat/db/sqlalchemy/api.py", line 368, in stack_get_all\n    marker, sort_dir, filters).all()\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/orm/query.py", line 2300, in all\n    return list(self)\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/orm/query.py", line 2412, in __iter__\n    return self._execute_and_instances(context)\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/orm/query.py", line 2427, in _execute_and_instances\n    result = conn.execute(querycontext.statement, self._params)\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 729, in execute\n    return meth(self, multiparams, params)\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/sql/elements.py", line 321, in _execute_on_connection\n    return connection._execute_clauseelement(self, multiparams, params)\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 826, in _execute_clauseelement\n    compiled_sql, distilled_params\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 958, in _execute_context\n    context)\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1156, in _handle_dbapi_exception\n    util.raise_from_cause(newraise, exc_info)\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/util/compat.py", line 199, in raise_from_cause\n    reraise(type(exception), exception, tb=exc_tb)\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 951, in _execute_context\n    context)\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/default.py", line 436, in do_execute\n    cursor.execute(statement, parameters)\n', u'  File "/usr/lib/python2.7/dist-packages/MySQLdb/cursors.py", line 174, in execute\n    self.errorhandler(self, exc, value)\n', u'  File "/usr/lib/python2.7/dist-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler\n    raise errorclass, errorvalue\n', u"DBConnectionError: (OperationalError) (2006, 'MySQL server has gone away') 'SELECT stack.status_reason AS stack_status_reason, stack.created_at AS stack_created_at, stack.deleted_at AS stack_deleted_at, stack.action AS stack_action, stack.status AS stack_status, stack.id AS stack_id, stack.name AS stack_name, stack.raw_template_id AS stack_raw_template_id, stack.username AS stack_username, stack.tenant AS stack_tenant, stack.parameters AS stack_parameters, stack.user_creds_id AS stack_user_creds_id, stack.owner_id AS stack_owner_id, stack.timeout AS stack_timeout, stack.disable_rollback AS stack_disable_rollback, stack.stack_user_project_id AS stack_stack_user_project_id, stack.backup AS stack_backup, stack.updated_at AS stack_updated_at \\nFROM stack \\nWHERE stack.deleted_at IS NULL AND stack.owner_id IS NULL AND stack.tenant = %s ORDER BY stack.created_at DESC, stack.id DESC' ('137b98f5d1974edb81700d97a4c423b0',)\n"].