floatingip-create on a subnet with exhausted IPs throws internal server error

Build 1.10 10

root@nodec22:~# neutron floatingip-create public_vn
Request Failed: internal server error while processing your request.
root@nodec22:~#

contrail-api log :
===============
<class 'cfgm_common.exceptions.HttpError'>
Python 2.7.3: /usr/bin/python
Sun Aug 10 12:04:49 2014

A problem occurred in a Python script. Here is the sequence of
function calls leading up to the error, in the order they occurred.

 /usr/lib/python2.7/dist-packages/vnc_openstack/neutron_plugin_interface.py in plugin_create_floatingip(self=<vnc_openstack.neutron_plugin_interface.NeutronPluginInterface object>, context={u'is_admin': True, u'operation': u'CREATE', u'roles': [u'Member', u'_member_', u'admin'], u'tenant': u'3088e9aba97b4f2ea6050275fc890f5c', u'tenant_id': u'3088e9aba97b4f2ea6050275fc890f5c', u'type': u'floatingip', u'user_id': u'b0cfcb54022b4f6d81fecbd339fb1f8a'}, floatingip={u'fields': None, u'filters': None, u'resource': {u'fixed_ip_address': None, u'floating_network_id': u'e376dbda-8ce7-40c8-983b-03beec6ae131', u'port_id': None, u'tenant_id': u'3088e9aba97b4f2ea6050275fc890f5c'}})
  496 try:
  497 cfgdb = self._get_user_cfgdb(context)
  498 net_info = cfgdb.floatingip_create(floatingip['resource'])
  499 return net_info
  500 except Exception as e:
net_info undefined
cfgdb = <vnc_openstack.neutron_plugin_db.DBInterface object>
cfgdb.floatingip_create = <bound method DBInterface.floatingip_create of <vnc_openstack.neutron_plugin_db.DBInterface object>>
floatingip = {u'fields': None, u'filters': None, u'resource': {u'fixed_ip_address': None, u'floating_network_id': u'e376dbda-8ce7-40c8-983b-03beec6ae131', u'port_id': None, u'tenant_id': u'3088e9aba97b4f2ea6050275fc890f5c'}}

 /usr/lib/python2.7/dist-packages/vnc_openstack/neutron_plugin_db.py in floatingip_create(self=<vnc_openstack.neutron_plugin_db.DBInterface object>, fip_q={u'fixed_ip_address': None, u'floating_network_id': u'e376dbda-8ce7-40c8-983b-03beec6ae131', u'port_id': None, u'tenant_id': u'3088e9aba97b4f2ea6050275fc890f5c'})
 3256 exc_info = {'type': 'BadRequest', 'message': msg}
 3257 bottle.abort(400, json.dumps(exc_info))
 3258 fip_uuid = self._vnc_lib.floating_ip_create(fip_obj)
 3259 fip_obj = self._vnc_lib.floating_ip_read(id=fip_uuid)
 3260
fip_uuid undefined
self = <vnc_openstack.neutron_plugin_db.DBInterface object>
self._vnc_lib = <vnc_api.vnc_api.VncApi object>
self._vnc_lib.floating_ip_create = <bound method VncApi.floating_ip_create of <vnc_api.vnc_api.VncApi object>>
fip_obj = <vnc_api.gen.resource_client.FloatingIp object>

 /usr/lib/python2.7/dist-packages/vnc_api/gen/vnc_api_client_gen.py in floating_ip_create(self=<vnc_api.vnc_api.VncApi object>, obj=<vnc_api.gen.resource_client.FloatingIp object>)
  994 content = self._request_server(rest.OP_POST,
  995 vnc_api.gen.resource_client.FloatingIp.create_uri,
  996 data = json_body)
  997
  998 floating_ip_dict = json.loads(content)['floating-ip']
data undefined
json_body = '{"floating-ip":{"project_refs": [{"to": ["defaul...refs": [], "floating_ip_fixed_ip_address": null}}'

 /usr/lib/python2.7/dist-packages/vnc_api/vnc_api.py in _request_server(self=<vnc_api.vnc_api.VncApi object>, op=1, url=u'/floating-ips', data='{"floating-ip":{"project_refs": [{"to": ["defaul...refs": [], "floating_ip_fixed_ip_address": null}}', retry_on_error=True, retry_after_authn=False)
  353 continue
  354 else: # Unknown Error
  355 raise HttpError(status, content)
  356 # end while True
  357
global HttpError = <class 'cfgm_common.exceptions.HttpError'>
status = 500
content = u"Virtual-Network([u'default-domain', u'public', u'public_vn']) has exhausted subnet(all)"
<class 'cfgm_common.exceptions.HttpError'>: HTTP Status: 500 Content: Virtual-Network([u'default-domain', u'public', u'public_vn']) has exhausted subnet(all)
    __class__ = <class 'cfgm_common.exceptions.HttpError'>
    __delattr__ = <method-wrapper '__delattr__' of HttpError object>
    __dict__ = {'content': u"Virtual-Network([u'default-domain', u'public', u'public_vn']) has exhausted subnet(all)", 'status_code': 500}
    __doc__ = None
    __format__ = <built-in method __format__ of HttpError object>
    __getattribute__ = <method-wrapper '__getattribute__' of HttpError object>
    __getitem__ = <method-wrapper '__getitem__' of HttpError object>
    __getslice__ = <method-wrapper '__getslice__' of HttpError object>
    __hash__ = <method-wrapper '__hash__' of HttpError object>
    __init__ = <bound method HttpError.__init__ of HttpError()>
    __module__ = 'cfgm_common.exceptions'
    __new__ = <built-in method __new__ of type object>
    __reduce__ = <built-in method __reduce__ of HttpError object>
    __reduce_ex__ = <built-in method __reduce_ex__ of HttpError object>
    __repr__ = <method-wrapper '__repr__' of HttpError object>
    __setattr__ = <method-wrapper '__setattr__' of HttpError object>
    __setstate__ = <built-in method __setstate__ of HttpError object>
    __sizeof__ = <built-in method __sizeof__ of HttpError object>
    __str__ = <bound method HttpError.__str__ of HttpError()>
    __subclasshook__ = <built-in method __subclasshook__ of type object>
    __unicode__ = <built-in method __unicode__ of HttpError object>
    __weakref__ = None
    args = ()
    content = u"Virtual-Network([u'default-domain', u'public', u'public_vn']) has exhausted subnet(all)"
    message = ''
    status_code = 500

The above is a description of an error in a Python program. Here is
the original traceback:

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/vnc_openstack/neutron_plugin_interface.py", line 498, in plugin_create_floatingip
    net_info = cfgdb.floatingip_create(floatingip['resource'])
  File "/usr/lib/python2.7/dist-packages/vnc_openstack/neutron_plugin_db.py", line 3258, in floatingip_create
    fip_uuid = self._vnc_lib.floating_ip_create(fip_obj)
  File "/usr/lib/python2.7/dist-packages/vnc_api/gen/vnc_api_client_gen.py", line 996, in floating_ip_create
    data = json_body)
  File "/usr/lib/python2.7/dist-packages/vnc_api/vnc_api.py", line 355, in _request_server
    raise HttpError(status, content)
HttpError: HTTP Status: 500 Content: Virtual-Network([u'default-domain', u'public', u'public_vn']) has exhausted subnet(all)

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/bottle.py", line 764, in _handle
    return route.call(**args)
  File "/usr/lib/python2.7/dist-packages/bottle.py", line 1575, in wrapper
    rv = callback(*a, **ka)
  File "/usr/lib/python2.7/dist-packages/vnc_openstack/neutron_plugin_interface.py", line 574, in plugin_http_post_floatingip
    return self.plugin_create_floatingip(context, floatingip)
  File "/usr/lib/python2.7/dist-packages/vnc_openstack/neutron_plugin_interface.py", line 502, in plugin_create_floatingip
    raise e
HttpError: HTTP Status: 500 Content: Virtual-Network([u'default-domain', u'public', u'public_vn']) has exhausted subnet(all)
10.204.217.108 - - [2014-08-10 12:04:49] "POST /neutron/floatingip HTTP/1.1" 500 156 0.109285