Comment 0 for bug 1809447

With rally tests i have noticed a generic performance drop in production on neutron from 100% to 10% in all components after migration to Ocata from Mitaka.
I'm able to reproduce the problem with isolated VM using ubuntu 16.04 packages with related repo and use create port as a test because seems the more relevant. Here below the times of 40 serial create port using curl direct to neutron:

mitaka 0m 21s
newton 0m 31s
ocata 0m 50s

I have done more tests with the next releases with devstack to check if the problem was solved, but unfortunately seems not.

I have also done a bit of profiling and seems also that the orm produce different behavior and have some call that on mitaka are never done:

ORMAdapter.traverse
ORMAdapter.replace
ORMAdapter._corresponding_column
ORMAdapter._locate_col