Looks like https://review.openstack.org/#/c/9510/ introduced a bug during instance spawn on nova-network.
Configured on a multi-node install using multi_host network config, FlatDHCPManager, auto_assign_floating_ips=True.
2012-07-26 21:07:31 DEBUG nova.openstack.common.rpc.amqp [-] unpacked context: {'project_name': None, 'user_id': None, 'roles': [u'admin'], 'timestamp': u'2012-07-27T01:07:23.872859', 'auth_token': '<SANITIZED>', 'remote_address': None, 'quota_class': None, 'is_admin': True, 'service_catalog': None, 'request_id': u'req-7fc46266-e08f-4ab4-a7f4-10e8eb5a5fbd', 'project_id': None, 'user_name': None, 'read_deleted': u'no'} from (pid=8724) _safe_log /usr/lib/python2.7/dist-packages/nova/openstack/common/rpc/common.py:199
2012-07-26 21:07:31 DEBUG nova.utils [req-7fc46266-e08f-4ab4-a7f4-10e8eb5a5fbd None None] Attempting to grab semaphore "get_dhcp" for method "_get_dhcp_ip"... from (pid=8724) inner /usr/lib/python2.7/dist-packages/nova/utils.py:661
2012-07-26 21:07:31 DEBUG nova.utils [req-7fc46266-e08f-4ab4-a7f4-10e8eb5a5fbd None None] Got semaphore "get_dhcp" for method "_get_dhcp_ip"... from (pid=8724) inner /usr/lib/python2.7/dist-packages/nova/utils.py:665
2012-07-26 21:07:31 ERROR nova.openstack.common.rpc.amqp [-] Exception during message handling
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp Traceback (most recent call last):
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/openstack/common/rpc/amqp.py", line 275, in _process_data
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp rval = self.proxy.dispatch(ctxt, version, method, **args)
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/openstack/common/rpc/dispatcher.py", line 145, in dispatch
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp return getattr(proxyobj, method)(ctxt, **kwargs)
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/network/manager.py", line 262, in wrapped
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp return func(self, context, *args, **kwargs)
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/network/manager.py", line 1028, in get_instance_nw_info
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp rxtx_factor, host)
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/network/manager.py", line 1049, in build_network_info_model
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp instance_host)
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/network/manager.py", line 1137, in _get_subnets_from_network
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp instance_host)
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/utils.py", line 679, in inner
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp retval = f(*args, **kwargs)
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/network/manager.py", line 812, in _get_dhcp_ip
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp host=host)
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/db/api.py", line 440, in fixed_ip_associate_pool
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp instance_uuid, host)
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/db/sqlalchemy/api.py", line 113, in wrapper
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp return f(*args, **kwargs)
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/db/sqlalchemy/api.py", line 1035, in fixed_ip_associate_pool
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp raise exception.InvalidUUID(uuid=instance_uuid)
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp InvalidUUID: Expected a uuid but received None.
2012-07-26 21:07:31 TRACE nova.openstack.common.rpc.amqp
Fix proposed to branch: master /review. openstack. org/10390
Review: https:/