Regarding the conversation started in March [1] about the use of OVN interconnect with Neutron, I would like to evolve the discussion in relation to resources allocated by OVN-IC and which are not managed by Neutron. In the March PTG [2], the problem related to the db_sync tool was presented, and a proposed solution in which Neutron does not manage these resources.
After discussing some architectural designs with Felix/StackIT, it seems to make sense to come up with a proposal to change the mech_driver to validate the external_ids key and not remove resources present in the OVN backend without Neutron "signature".
The discussion here is more complex than it seems, because architecturally Neutron does not allow us to interconnect workloads in multiple AZs (with different OpenStacks), but this could be a requirement for a high availability cloud solution (Cloud Region). Additionally, this OVN-IC solution allows interconnecting other cloud backends that use OVN, in the case of kubernetes with ovn-kube.
We tested an OVN interconnect integrated with 3 OpenStack installations and it worked very well !!! considering direct L3 traffic at the router level between different network infrastructures.
SYNC_REPAIR - problem
* Static Routes (learned OVN-IC routes)
* Router Port -> Transit Switches
Jul 10 18:34:11 os-infra-1-neutron-server-container-845157ae neutron-server[8632]: 2023-07-10 18:34:11.343 8632 WARNING neutron.plugins.ml2.drivers.ovn.mech_driver.ovsdb.ovn_db_sync [req-8d513732-f932-47b8-bc2c-937958c30f47 - - - - -] Router Port found in OVN but not in Neutron, port_id=rt2-admin-tenant1
Jul 10 18:34:11 os-infra-1-neutron-server-container-845157ae neutron-server[8632]: 2023-07-10 18:34:11.343 8632 WARNING neutron.plugins.ml2.drivers.ovn.mech_driver.ovsdb.ovn_db_sync [req-8d513732-f932-47b8-bc2c-937958c30f47 - - - - -] Router 9823d34b-bb2a-480c-b3f6-cf51fd19db52 static routes [{'destination': '
10.0.0.1/24', 'nexthop': '169.254.100.1'}, {'destination': '
10.0.2.1/24', 'nexthop': '169.254.100.3'}] found in OVN but not in Neutron
Any suggestions on how to resolve this db_sync issue? since all other Neutron modules did not present any problem with OVN-IC (as far as I tested).
I remember Terry was keen to suggest some things to help. I believe that before proposing some complex mechanism to solve this simple problem, I would like to hear the community opinion. In our use case, a bit change in db_sync with filter by neutron key in external_ids would be enough.
Regards,
Roberto
[1]
https://lists.openstack.org/pipermail/openstack-discuss/2023-March/032624.html[2]
https://etherpad.opendev.org/p/neutron-bobcat-ptgAdditional logs:
OpenStack 1
root@os-infra-1-neutron-ovn-northd-container-f931b37c:~#
root@os-infra-1-neutron-ovn-northd-container-f931b37c:~#
root@os-infra-1-neutron-ovn-northd-container-f931b37c:~# ovn-nbctl lr-route-list 6b776115-746a-4c59-aa73-6674c70b3498
IPv4 Routes
Route Table <main>:
20.0.1.0/24 169.254.200.2 dst-ip (learned)
20.0.2.0/24 169.254.200.3 dst-ip (learned)
0.0.0.0/0 200.200.200.1 dst-ip
IPv6 Routes
Route Table <main>:
::/0 fc00:ca5a:ca5a:8000:: dst-ip
root@os-infra-1-neutron-ovn-northd-container-f931b37c:~# ovn-nbctl lr-route-list 23d4552a-62c4-40e1-8bae-d06af3489c07
IPv4 Routes
Route Table <main>:
10.0.1.0/24 169.254.100.2 dst-ip (learned)
10.0.2.0/24 169.254.100.3 dst-ip (learned)
0.0.0.0/0 200.200.200.1 dst-ip
IPv6 Routes
Route Table <main>:
::/0 fc00:ca5a:ca5a:8000:: dst-ip
root@os-infra-1-neutron-ovn-northd-container-f931b37c:~#
OpenStack 2
root@os-infra-1-neutron-ovn-northd-container-30f7e935:~# ovn-nbctl lr-route-list dc1e5008-adb9-451e-8b71-09388f3680bc
IPv4 Routes
Route Table <main>:
20.0.0.0/24 169.254.200.1 dst-ip (learned)
20.0.2.0/24 169.254.200.3 dst-ip (learned)
0.0.0.0/0 200.200.200.1 dst-ip
IPv6 Routes
Route Table <main>:
::/0 fc00:ca5a:ca5a:8000:: dst-ip
root@os-infra-1-neutron-ovn-northd-container-30f7e935:~# ovn-nbctl lr-route-list ce45f681-6454-43fe-974f-81344bb8113a
IPv4 Routes
Route Table <main>:
10.0.0.0/24 169.254.100.1 dst-ip (learned)
10.0.2.0/24 169.254.100.3 dst-ip (learned)
0.0.0.0/0 200.200.200.1 dst-ip
IPv6 Routes
Route Table <main>:
::/0 fc00:ca5a:ca5a:8000:: dst-ip
OpenStack 3
root@os-infra-1-neutron-ovn-northd-container-f237db97:~#
root@os-infra-1-neutron-ovn-northd-container-f237db97:~# ovn-nbctl lr-route-list cfa259d6-311f-4409-bcf2-79a929835cb3
IPv4 Routes
Route Table <main>:
20.0.0.0/24 169.254.200.1 dst-ip (learned)
20.0.1.0/24 169.254.200.2 dst-ip (learned)
0.0.0.0/0 200.200.200.1 dst-ip
IPv6 Routes
Route Table <main>:
::/0 fc00:ca5a:ca5a:8000:: dst-ip
root@os-infra-1-neutron-ovn-northd-container-f237db97:~# ovn-nbctl lr-route-list c5a4dcd8-b9a6-4397-a7cf-88bc1e01b0b0
IPv4 Routes
Route Table <main>:
10.0.0.0/24 169.254.100.1 dst-ip (learned)
10.0.1.0/24 169.254.100.2 dst-ip (learned)
0.0.0.0/0 200.200.200.1 dst-ip
IPv6 Routes
Route Table <main>:
::/0 fc00:ca5a:ca5a:8000:: dst-ip
OVN-IC Global database
root@ovn-global-db1:~# ovn-ic-sbctl show
availability-zone osp1
gateway 832b6c0d-13ce-4600-ab37-78516d8ec4c5
hostname: osp1-gwnode1
type: geneve
ip: 192.168.200.28
port admin-rt1-tenant1
transit switch: admin-tenant1
address: ["aa:aa:aa:aa:bb:01
169.254.100.1/24 fe80::1/64"]
port admin-rt1-tenant1_1
transit switch: admin-tenant1_1
address: ["aa:aa:aa:aa:dd:01
169.254.200.1/24"]
availability-zone osp2
gateway 17ffabdf-cf47-41ab-9539-d326c13c4ca8
hostname: osp2-gwnode1
type: geneve
ip: 192.168.200.128
port admin-rt2-tenant1
transit switch: admin-tenant1
address: ["aa:aa:aa:aa:bb:02
169.254.100.2/24 fe80::2/64"]
port admin-rt2-tenant1_1
transit switch: admin-tenant1_1
address: ["aa:aa:aa:aa:dd:02
169.254.200.2/24"]
availability-zone osp3
gateway 97595af9-7896-40d0-a883-beadbff1aa5b
hostname: osp3-gwnode1
type: geneve
ip: 192.168.200.228
port admin-rt3-tenant1
transit switch: admin-tenant1
address: ["aa:aa:aa:aa:aa:03
169.254.100.3/24 fe80::3/64"]
port admin-rt3-tenant1_1
transit switch: admin-tenant1_1
address: ["aa:aa:aa:aa:dd:03
169.254.200.3/24"]