I've just upgraded from openstack queens to rocky and then to stein on centos 7.
In my configuration I have router high availability.
After the upgrade I get the following errors on all my 3 controllers under /var/log/neutron/l3-agent.log
2021-05-15 19:04:28.599 13219 ERROR neutron.agent.linux.external_process [-] ip_monitor for router with uuid 8c137f17-52e6-47f9-bcaa-0eac94a9acd7 not found. The process should not have died
2021-05-15 19:04:28.600 13219 WARNING neutron.agent.linux.external_process [-] Respawning ip_monitor for uuid 8c137f17-52e6-47f9-bcaa-0eac94a9acd7
2021-05-15 19:04:29.905 13219 ERROR neutron.agent.linux.external_process [-] ip_monitor for router with uuid 303c88e4-1c94-4ebc-b592-91063b371db9 not found. The process should not have died
2021-05-15 19:04:29.905 13219 WARNING neutron.agent.linux.external_process [-] Respawning ip_monitor for uuid 303c88e4-1c94-4ebc-b592-91063b371db9
2021-05-15 19:04:31.267 13219 ERROR neutron.agent.linux.external_process [-] ip_monitor for router with uuid 103f3588-a775-4bca-b7a5-093a05068f64 not found. The process should not have died
2021-05-15 19:04:31.268 13219 WARNING neutron.agent.linux.external_process [-] Respawning ip_monitor for uuid 103f3588-a775-4bca-b7a5-093a05068f64
2021-05-15 19:04:32.684 13219 ERROR neutron.agent.linux.external_process [-] ip_monitor for router with uuid c6136e08-16a3-4d56-9440-59a7fe90d0b0 not found. The process should not have died
2021-05-15 19:04:32.685 13219 WARNING neutron.agent.linux.external_process [-] Respawning ip_monitor for uuid c6136e08-16a3-4d56-9440-59a7fe90d0b0
2021-05-15 19:04:34.140 13219 ERROR neutron.agent.linux.external_process [-] ip_monitor for router with uuid 9abaad3a-2439-4036-8611-5f93a8a3501f not found. The process should not have died
2021-05-15 19:04:34.140 13219 WARNING neutron.agent.linux.external_process [-] Respawning ip_monitor for uuid 9abaad3a-2439-4036-8611-5f93a8a3501f
Getting for example the last uuid if I execute "openstack router show openstack router show 9abaad3a-2439-4036-8611-5f93a8a3501f
+-------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Field | Value |
+-------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| admin_state_up | UP |
| availability_zone_hints | |
| availability_zones | nova |
| created_at | 2020-12-17T10:11:24Z |
| description | |
| distributed | False |
| external_gateway_info | None |
| flavor_id | None |
| ha | True |
| id | 9abaad3a-2439-4036-8611-5f93a8a3501f |
| interfaces_info | [{"subnet_id": "a60b631d-d13c-4d02-a51b-2c86c0b38614", "ip_address": "192.168.201.1", "port_id": "08120fb0-be86-47a0-afd6-932801a2d194"}, {"subnet_id": "0ffcb170-66bb-4e65-9df0-80052deb1299", "ip_address": "169.254.192.11", "port_id": "3aa676aa-91cc-43c4-87ea-3b93340950ad"}, {"subnet_id": "0ffcb170-66bb-4e65-9df0-80052deb1299", "ip_address": "169.254.192.21", "port_id": "d5c0cff2-363d-470a-b77c-155d06e2654b"}, {"subnet_id": "0ffcb170-66bb-4e65-9df0-80052deb1299", "ip_address": "169.254.192.3", "port_id": "dab50b1a-d720-410a-b358-20c53a097bd7"}, {"subnet_id": "ae117b0e-fce9-42ca-88b3-a32ba239d795", "ip_address": "192.168.96.59", "port_id": "e49945aa-3e71-4f38-8c76-1c246cf18ff6"}] |
| location | Munch({'project': Munch({'domain_name': None, 'domain_id': None, 'name': None, 'id': u'07573f587ceb4d9da007cec4ebc5dcf8'}), 'cloud': '', 'region_name': '', 'zone': None}) |
| name | InternetGateway-a820a62fae-avz714-3-router |
| project_id | 07573f587ceb4d9da007cec4ebc5dcf8 |
| revision_number | 11 |
| routes | destination='
0.0.0.0/0', gateway='192.168.96.60' |
| | destination='
192.168.200.0/24', gateway='192.168.96.60' |
| | destination='
192.168.202.0/24', gateway='192.168.96.58' |
| | destination='
192.168.203.0/24', gateway='192.168.96.57' |
| status | ACTIVE |
| tags | |
| updated_at | 2020-12-18T15:22:57Z |
+-------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
Namespace for router exists in all 3 controllers.