博主你好，我是按照你的书来学习OpenStack的学生，在安装计算节点的时候遇到下面的这个问题，请问怎么解决？
--os-region RegionOne compute service list --host wenfeng-virtual-machine --service nova-compute -c ID -f value
Unable to establish connection to http://192.168.116.153:8774/v2.1/os-services?host=wenfeng-virtual-machine&binary=nova-compute: HTTPConnectionPool(host='192.168.116.153', port=8774): Max retries exceeded with url: /v2.1/os-services?host=wenfeng-virtual-machine&binary=nova-compute (Caused by NewConnectionError('<requests.packages.urllib3.connection.HTTPConnection object at 0x7fd087924190>: Failed to establish a new connection: [Errno 111] Connection refused',))
+:: ID=
+:: [[ '' == '' ]]
+:: sleep 1
++:: openstack --os-cloud devstack-admin
十分感谢！