RHOSP : neutron API return 500 internal server error or 504 Gateway Time-out

Issue

During neutron api call :

• openstack network list
• openstack network create todal

the results are:

• code 50X return with one of the following message

Error while executing command: HttpException: 500, {"NeutronError": {"type": "HTTPInternalServerError", "message": "Request Failed: internal server error while processing your request.", "detail": ""}}

Error while executing command: HttpException: 504, 504 Gateway Time-out The server didn't respond in time.

• In /var/log/containers/httpd/neutron-api/neutron-api-proxy_access_ssl.log:

172.1.1.1 - - [01/Jan/2023:00:00:00 UTC] "POST /v2.0/networks HTTP/1.1" 500 150 "-" "openstacksdk/0.17.2 keystoneauth1/3.10.0 python-requests/2.21.0 CPython/2.7.16"

• In /var/log/containers/neutron/server.log For 500 error:

2023-01-01 00:00:00.00 19 ERROR neutron.pecan_wsgi.hooks.translation [req-32212ae5-ee2d-413c-9523-a6c6c0a2d364 fc7944fbb7a8a8e339c9209ba14750e5261a012d3140e2bc2cbd186b6e2b78e5 19ce5d8b4ca44788b3a5f87f54a4adfa - b2743393b30b4fa48572113b7c5baec6 b2743393b30b4fa48572113b7c5baec6] POST failed.: sqlalchemy.exc.TimeoutError: QueuePool limit of size 5 overflow 50 reached, connection timed out, timeout 30 (Background on this error at: http://sqlalche.me/e/3o7r)
2023-01-01 00:00:00.00 19 INFO neutron.wsgi [req-32212ae5-ee2d-413c-9523-a6c6c0a2d364 fc7944fbb7a8a8e339c9209ba14750e5261a012d3140e2bc2cbd186b6e2b78e5 19ce5d8b4ca44788b3a5f87f54a4adfa - b2743393b30b4fa48572113b7c5baec6 b2743393b30b4fa48572113b7c5baec6] 10.1.1.1,172.1.1.1,::1 "POST /v2.0/networks HTTP/1.1" status: 500  len: 368 time: 30.1104324

• in /var/log/containers/httpd/neutron-api/neutron-api-proxy_access_ssl.log for 504 error:

172.1.1.1 - - [01/Jan/2023:00:00:00 UTC] "POST /v2.0/networks HTTP/1.1" 502 341 "-" "openstacksdk/0.17.2 keystoneauth1/3.10.0 python-requests/2.21.0 CPython/2.7.16"