Hi Ali, I believe you can explore the ovs-save tool to save the OF flows before upgrading the chassi and restore the OF flows after upgrading the OVS package. It will depend on the amount of OF flows that you have on the chassis that determine the downtime on the dataplane that you will have.
Example: #save the OF flows /usr/share/openvswitch/scripts/ovs-save save-flows <bridge> /tmp/offlows_saved.sh #restore the OF flows sh /tmp/offlows_saved.sh I recommend you to try it in a lab or some controlled place to homologate the steps. Regards, Tiago Pires On Tue, Jul 1, 2025 at 4:17 AM Ali AKYÜREK via discuss <[email protected]> wrote: > > Hi Team, > > I’m running an OpenStack cluster deployed using Kolla-Ansible, and I’m using > OpenvSwitch (OVS) as the neutron_plugin_agent. I want to upgrade to OpenStack > with zero-downtime. > > During an upgrade of the OVS components (openvswitch-db and > openvswitch-vswitchd), I observe that the flows are lost. These flows do not > get recreated until the neutron-openvswitch-agent service is manually > restarted, which causes a noticeable disruption in network connectivity. > > As a workaround, I’ve tried the following sequence: > > docker exec openvswitch_vswitchd ovs-appctl -T 5 -t ovs-vswitchd exit > docker restart openvswitch_db > docker start openvswitch_vswitchd > > With this approach, the downtime is reduced to approximately 10 seconds, and > the flows are restored without restarting the Neutron agent. > > However, I’m looking for a way to perform the upgrade with zero downtime, or > at least without having to restart the neutron-openvswitch-agent service. > > During the issue, I noticed the following recurring log messages in > neutron-openvswitch-agent: > > 2025-06-25 09:12:34.977 7 ERROR neutron.agent.common.ovsdb_monitor [...] > Interface monitor is not active > ... > 2025-06-25 09:12:44.980 7 ERROR neutron.agent.common.ovsdb_monitor [...] > Interface monitor is not active > > These messages appear every few seconds until the agent is restarted. Full > log snippet: > > 2025-06-25 09:12:34.976 INFO ovs_neutron_agent [...] Agent rpc_loop - > iteration:17887 started > 2025-06-25 09:12:34.977 ERROR ovsdb_monitor [...] Interface monitor is > not active > 2025-06-25 09:12:34.977 INFO ovs_neutron_agent [...] Agent rpc_loop - > iteration:17887 completed. Processed ports statistics: {'regular': {'added': > 0, 'updated': 0, 'removed': 0}}. Elapsed:0.001 > ... > 2025-06-25 09:12:46.981 INFO ovs_neutron_agent [...] Agent rpc_loop - > iteration:17893 - starting polling. Elapsed:0.001 > 2025-06-25 09:12:46.982 INFO ovs_neutron_agent [...] Agent rpc_loop - > iteration:17893 - port information retrieved. Elapsed:0.002 > > Has anyone encountered a similar issue or found a reliable strategy for > upgrading OVS in a containerized Kolla environment without flow loss? > > Thanks in advance for your support and suggestions. > > Best regards, > > Ali > > _______________________________________________ > discuss mailing list > [email protected] > https://mail.openvswitch.org/mailman/listinfo/ovs-discuss -- _‘Esta mensagem é direcionada apenas para os endereços constantes no cabeçalho inicial. Se você não está listado nos endereços constantes no cabeçalho, pedimos-lhe que desconsidere completamente o conteúdo dessa mensagem e cuja cópia, encaminhamento e/ou execução das ações citadas estão imediatamente anuladas e proibidas’._ * **‘Apesar do Magazine Luiza tomar todas as precauções razoáveis para assegurar que nenhum vírus esteja presente nesse e-mail, a empresa não poderá aceitar a responsabilidade por quaisquer perdas ou danos causados por esse e-mail ou por seus anexos’.* _______________________________________________ discuss mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
