hi:i change the code by you ,but still get the error:
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host [req-9f0f7a12-5947-4d8d-be12-904376ab13cc f78cc871fb804d548b956ca8971dbf32 500ef1d3e27a410daad8075fd915087e - - -] Connection to libvirt failed: Failed to connect socket to '/var/run/libvirt/libvirt-sock': Connection refused
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host Traceback (most recent call last):
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host   File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/host.py", line 411, in get_connection
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host     conn = self._get_connection()
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host   File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/host.py", line 398, in _get_connection
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host     wrapped_conn = self._get_new_connection()
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host   File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/host.py", line 350, in _get_new_connection
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host     wrapped_conn = self._connect(self._uri, self._read_only)
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host   File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/host.py", line 204, in _connect
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host     libvirt.openAuth, uri, auth, flags)
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host   File "/usr/lib/python2.7/site-packages/eventlet/tpool.py", line 144, in proxy_call
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host     rv = execute(f, *args, **kwargs)
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host   File "/usr/lib/python2.7/site-packages/eventlet/tpool.py", line 125, in execute
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host     six.reraise(c, e, tb)
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host   File "/usr/lib/python2.7/site-packages/eventlet/tpool.py", line 83, in tworker
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host     rv = meth(*args, **kwargs)
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host   File "/usr/lib64/python2.7/site-packages/libvirt.py", line 105, in openAuth
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host     if ret is None:raise libvirtError('virConnectOpenAuth() failed')
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host libvirtError: Failed to connect socket to '/var/run/libvirt/libvirt-sock': Connection refused
2016-12-29 05:14:24.367 2371 ERROR nova.virt.libvirt.host
2016-12-29 05:14:24.371 2371 WARNING nova.compute.manager [req-9f0f7a12-5947-4d8d-be12-904376ab13cc f78cc871fb804d548b956ca8971dbf32 500ef1d3e27a410daad8075fd915087e - - -] Could not clean up failed build, not rescheduling. Error: Connection to the hypervisor is broken on host: OS-N-Compute-1
2016-12-29 05:14:24.729 2371 ERROR nova.compute.manager [req-9f0f7a12-5947-4d8d-be12-904376ab13cc f78cc871fb804d548b956ca8971dbf32 500ef1d3e27a410daad8075fd915087e - - -] [instance: b40d05c9-5616-433b-9333-bca270f5873e] Build of instance b40d05c9-5616-433b-9333-bca270f5873e aborted: internal error: client socket is closed
2016-12-29 05:14:24.729 2371 ERROR nova.compute.manager [instance: b40d05c9-5616-433b-9333-bca270f5873e] Traceback (most recent call last):
2016-12-29 05:14:24.729 2371 ERROR nova.compute.manager [instance: b40d05c9-5616-433b-9333-bca270f5873e]   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 1779, in _do_build_and_run_instance
2016-12-29 05:14:24.729 2371 ERROR nova.compute.manager [instance: b40d05c9-5616-433b-9333-bca270f5873e]     filter_properties)
2016-12-29 05:14:24.729 2371 ERROR nova.compute.manager [instance: b40d05c9-5616-433b-9333-bca270f5873e]   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 1939, in _build_and_run_instance
2016-12-29 05:14:24.729 2371 ERROR nova.compute.manager [instance: b40d05c9-5616-433b-9333-bca270f5873e]     'create.error', fault=e)
2016-12-29 05:14:24.729 2371 ERROR nova.compute.manager [instance: b40d05c9-5616-433b-9333-bca270f5873e]   File "/usr/lib/python2.7/site-packages/oslo_utils/excutils.py", line 220, in __exit__
2016-12-29 05:14:24.729 2371 ERROR nova.compute.manager [instance: b40d05c9-5616-433b-9333-bca270f5873e]     self.force_reraise()
2016-12-29 05:14:24.729 2371 ERROR nova.compute.manager [instance: b40d05c9-5616-433b-9333-bca270f5873e]   File "/usr/lib/python2.7/site-packages/oslo_utils/excutils.py", line 196, in force_reraise
2016-12-29 05:14:24.729 2371 ERROR nova.compute.manager [instance: b40d05c9-5616-433b-9333-bca270f5873e]     six.reraise(self.type_, self.value, self.tb)
2016-12-29 05:14:24.729 2371 ERROR nova.compute.manager [instance: b40d05c9-5616-433b-9333-bca270f5873e]   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 1923, in _build_and_run_instance
2016-12-29 05:14:24.729 2371 ERROR nova.compute.manager [instance: b40d05c9-5616-433b-9333-bca270f5873e]     instance=instance)
2016-12-29 05:14:24.729 2371 ERROR nova.compute.manager [instance: b40d05c9-5616-433b-9333-bca270f5873e]   File "/usr/lib64/python2.7/contextlib.py", line 35, in __exit__
2016-12-29 05:14:24.729 2371 ERROR nova.compute.manager [instance: b40d05c9-5616-433b-9333-bca270f5873e]     self.gen.throw(type, value, traceback)
2016-12-29 05:14:24.729 2371 ERROR nova.compute.manager [instance: b40d05c9-5616-433b-9333-bca270f5873e]   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 2105, in _build_resources
2016-12-29 05:14:24.729 2371 ERROR nova.compute.manager [instance: b40d05c9-5616-433b-9333-bca270f5873e]     reason=six.text_type(exc))
2016-12-29 05:14:24.729 2371 ERROR nova.compute.manager [instance: b40d05c9-5616-433b-9333-bca270f5873e] BuildAbortException: Build of instance b40d05c9-5616-433b-9333-bca270f5873e aborted: internal error: client socket is closed
2016-12-29 05:14:24.729 2371 ERROR nova.compute.manager [instance: b40d05c9-5616-433b-9333-bca270f5873e]