Comment 3 for bug 1777968

@Brain,
We try to add such change [1] locally, and the port creating result looks better, 987 ports created successfully for 1000 API requests. Without such change, it will have 500+ API fail.
Yes, such change seems not the best way, we need to look deeper in [2], [3] and the [database] config.

[1] https://review.openstack.org/577739
[2] https://github.com/openstack/neutron/blob/master/neutron/ipam/drivers/neutrondb_ipam/driver.py#L170-#L173
[3] https://github.com/openstack/neutron/blob/master/neutron/db/api.py#L71-#L76