Unable to delete an instance when publicURL is not reachable from nova-compute

Issue

• Unable to delete an instance when publicURL is not reachable from nova-compute because nova-compute cannot connect to cinder volume catalog

• The following error is shown in /var/log/nova/nova-compute.log

2015-09-07 01:28:53.161 44693 ERROR nova.compute.manager [req-1dd4d15a-4de2-432d-bd3f-15e12f40b6f7 487d5d3692fc4a678ca5012f3b1e3878 e7d35ba74a894b9bad6df1ee82d7d383] [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42] Failed to attach 8b8de33d-d3ab-4a01-ad7a-92f439789157 at /dev/vdb
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42] Traceback (most recent call last):
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42]   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 4262, in _attach_volume
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42]     do_check_attach=False, do_driver_attach=True)
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42]   File "/usr/lib/python2.7/site-packages/nova/virt/block_device.py", line 45, in wrapped
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42]     ret_val = method(obj, context, *args, **kwargs)
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42]   File "/usr/lib/python2.7/site-packages/nova/virt/block_device.py", line 224, in attach
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42]     volume = volume_api.get(context, self.volume_id)
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42]   File "/usr/lib/python2.7/site-packages/nova/volume/cinder.py", line 174, in wrapper
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42]     res = method(self, ctx, volume_id, *args, **kwargs)
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42]   File "/usr/lib/python2.7/site-packages/nova/volume/cinder.py", line 207, in get
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42]     item = cinderclient(context).volumes.get(volume_id)
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42]   File "/usr/lib/python2.7/site-packages/cinderclient/v1/volumes.py", line 196, in get
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42]     return self._get("/volumes/%s" % volume_id, "volume")
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42]   File "/usr/lib/python2.7/site-packages/cinderclient/base.py", line 145, in _get
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42]     resp, body = self.api.client.get(url)
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42]   File "/usr/lib/python2.7/site-packages/cinderclient/client.py", line 220, in get
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42]     return self._cs_request(url, 'GET', **kwargs)
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42]   File "/usr/lib/python2.7/site-packages/cinderclient/client.py", line 212, in _cs_request
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42]     raise exceptions.ConnectionError(msg)
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42] ConnectionError: Unable to establish connection: ('Connection aborted.', error(110, 'ETIMEDOUT'))
2015-09-07 01:28:53.161 44693 TRACE nova.compute.manager [instance: cb0f85ab-633c-46ef-bd5e-df043f470b42] 
2015-09-07 01:28:53.164 44693 DEBUG nova.volume.cinder [req-1dd4d15a-4de2-432d-bd3f-15e12f40b6f7 487d5d3692fc4a678ca5012f3b1e3878 e7d35ba74a894b9bad6df1ee82d7d383] Cinderclient connection created using URL: http://10.10.10.10:8776/v1/e7d35ba74a894b9bad6df1ee82d7d383 cinderclient /usr/lib/python2.7/site-packages/nova/volume/cinder.py:94
2015-09-07 01:28:53.166 44693 INFO requests.packages.urllib3.connectionpool [-] Starting new HTTP connection (1): 10.10.10.10