Under load rally tests with port deletion

In performance test for nsxv, one test case failed in 2 iterations due to the below error

failed request ids
------------------
req-52e6ac64-223e-4967-a1c0-78cafa79c347
req-cd006124-67f5-4f4a-82e8-6476223d33d5

Test case details - concurrency/iteration - 25/15
-------------------------------------------------
1) create 1 tenant
2) create 1 user per tenant
3) create 3 networks per network
4) create 1 subnet per network
5) create 1 port per subnet
6) create 3 security groups
7) create 10 rules per one security group
8) create exclusive router (exclusive type)
9) add to 'external' network and subnets gateways to exclusive router
9) create three vms - app, db, web with above subnet ports
10) add floating ip to the web vm
11) verify ping from rally vm

neutron-server.log
------------------
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils [req-52e6ac64-223e-4967-a1c0-78cafa79c347 8590722fbc054e83b11db086234707ca f4d9fa3fab5044e8848b105fb3a72420 - - -] Failed to delete port: a6deeab0-ae54-49ae-9e35-16e3363da437
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils Traceback (most recent call last):
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils File "/usr/lib/python2.7/dist-packages/neutron/plugins/common/utils.py", line 194, in delete_port_on_error
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils l3_port_check=False)
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils File "/usr/lib/python2.7/dist-packages/vmware_nsx/plugins/nsx_v/plugin.py", line 2131, in delete_port
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils neutron_db_port = self.get_port(context, id)
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils File "/usr/lib/python2.7/dist-packages/neutron/db/api.py", line 166, in wrapped
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils return method(*args, **kwargs)
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils File "/usr/lib/python2.7/dist-packages/neutron/db/api.py", line 95, in wrapped
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils setattr(e, '_RETRY_EXCEEDED', True)
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils File "/usr/lib/python2.7/dist-packages/oslo_utils/excutils.py", line 220, in __exit__
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils self.force_reraise()
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils File "/usr/lib/python2.7/dist-packages/oslo_utils/excutils.py", line 196, in force_reraise
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils six.reraise(self.type_, self.value, self.tb)
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils File "/usr/lib/python2.7/dist-packages/neutron/db/api.py", line 91, in wrapped
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils return f(*args, **kwargs)
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils File "/usr/lib/python2.7/dist-packages/oslo_db/api.py", line 151, in wrapper
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils ectxt.value = e.inner_exc
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils File "/usr/lib/python2.7/dist-packages/oslo_utils/excutils.py", line 220, in __exit__
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils self.force_reraise()
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils File "/usr/lib/python2.7/dist-packages/oslo_utils/excutils.py", line 196, in force_reraise
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils six.reraise(self.type_, self.value, self.tb)
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils File "/usr/lib/python2.7/dist-packages/oslo_db/api.py", line 139, in wrapper
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils return f(*args, **kwargs)
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils File "/usr/lib/python2.7/dist-packages/neutron/db/api.py", line 131, in wrapped
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils traceback.format_exc())
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils File "/usr/lib/python2.7/dist-packages/oslo_utils/excutils.py", line 220, in __exit__
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils self.force_reraise()
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils File "/usr/lib/python2.7/dist-packages/oslo_utils/excutils.py", line 196, in force_reraise
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils six.reraise(self.type_, self.value, self.tb)
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils File "/usr/lib/python2.7/dist-packages/neutron/db/api.py", line 126, in wrapped
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils return f(*dup_args, **dup_kwargs)
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils File "/usr/lib/python2.7/dist-packages/neutron/db/db_base_plugin_v2.py", line 1304, in get_port
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils port = self._get_port(context, id)
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils File "/usr/lib/python2.7/dist-packages/neutron/db/db_base_plugin_common.py", line 220, in _get_port
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils raise n_exc.PortNotFound(port_id=id)
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils PortNotFound: Port a6deeab0-ae54-49ae-9e35-16e3363da437 could not be found.
2017-05-25 14:37:45.894 19756 ERROR neutron.plugins.common.utils
2017-05-25 14:37:45.896 19756 INFO neutron.api.v2.resource [req-52e6ac64-223e-4967-a1c0-78cafa79c347 8590722fbc054e83b11db086234707ca f4d9fa3fab5044e8848b105fb3a72420 - - -] add_router_interface failed (client error): The resource could not be found.
2017-05-25 14:37:45.897 19756 INFO neutron.wsgi [req-52e6ac64-223e-4967-a1c0-78cafa79c347 8590722fbc054e83b11db086234707ca f4d9fa3fab5044e8848b105fb3a72420 - - -] 172.18.2.228,172.17.66.14 - - [25/May/2017 14:37:45] "PUT /v2.0/routers/f2155c4d-c863-4b85-843b-fe8d1aab5756/add_router_interface.json HTTP/1.1" 404 333 1.251514