If a VM with a floating IP is deleted while concurrently deleting the floating IP (i.e. "nova delete" and "neutron floatingip-delete") the VM may go into error state.
Nova receives a 500 error code from neutron because neutron fails to delete the port and the following stack is observed:
2015-11-04 21:48:37.447 17275 ERROR neutron.api.v2.resource [req-764172bc-4938-440d-9e6a-dd4c0f120f1b ] delete failed
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource Traceback (most recent call last):
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/neutron/api/v2/resource.py", line 83, in resource
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource result = method(request=request, **args)
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/neutron/api/v2/base.py", line 490, in delete
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource obj_deleter(request.context, id, **kwargs)
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/oslo_db/api.py", line 131, in wrapper
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource return f(*args, **kwargs)
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/neutron/plugins/ml2/plugin.py", line 1272, in delete_port
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource context, id, do_notify=False)
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/neutron/db/l3_dvr_db.py", line 274, in disassociate_floatingips
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource do_notify=do_notify)
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/neutron/db/l3_db.py", line 1361, in disassociate_floatingips
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource context, port_id)
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/neutron/db/l3_db.py", line 1088, in disassociate_floatingips
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource 'router_id': None})
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/sqlalchemy/orm/session.py", line 483, in __exit__
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource self.rollback()
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/sqlalchemy/util/langhelpers.py", line 60, in __exit__
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource compat.reraise(exc_type, exc_value, exc_tb)
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/sqlalchemy/orm/session.py", line 480, in __exit__
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource self.commit()
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/sqlalchemy/orm/session.py", line 385, in commit
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource self._prepare_impl()
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/sqlalchemy/orm/session.py", line 365, in _prepare_impl
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource self.session.flush()
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/sqlalchemy/orm/session.py", line 1986, in flush
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource self._flush(objects)
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/sqlalchemy/orm/session.py", line 2104, in _flush
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource transaction.rollback(_capture_exception=True)
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/sqlalchemy/util/langhelpers.py", line 60, in __exit__
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource compat.reraise(exc_type, exc_value, exc_tb)
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/sqlalchemy/orm/session.py", line 2068, in _flush
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource flush_context.execute()
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/sqlalchemy/orm/unitofwork.py", line 372, in execute
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource rec.execute(self)
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/sqlalchemy/orm/unitofwork.py", line 526, in execute
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource uow
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/sqlalchemy/orm/persistence.py", line 61, in save_obj
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource mapper, table, update)
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource File "/opt/neutron/lib/python2.7/site-packages/sqlalchemy/orm/persistence.py", line 537, in _emit_update_statements
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource (table.description, len(update), rows))
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource StaleDataError: UPDATE statement on table 'floatingips' expected to update 1 row(s); 0 were matched.
2015-11-04 21:48:37.447 17275 TRACE neutron.api.v2.resource
Version: stable/kilo
Thanks for the bug report! Is there a way you could try this on Liberty or master to verify it's existence there? Kilo is in security only mode at this time.