Public bug reported: This is a separation from the discussion in this bug https://bugs.launchpad.net/neutron/+bug/1815989
There comment https://bugs.launchpad.net/neutron/+bug/1815989/comments/52 goes through in detail the flow on a Train deployment using neutron 15.1.0 (controller) and 15.3.0 (compute) and nova 20.4.0 There is a race condition where nova live-migration will wait for neutron to send the network-vif-plugged event but when nova receives that event the live migration is faster than the OVS l2 agent can bind the port on the destination compute node. This causes the RARP frames sent out to update the switches ARP tables to fail causing the instance to be completely unaccessible after a live migration unless these RARP frames are sent again or traffic is initiated egress from the instance. See Sean's comments after for the view from the Nova side. The correct behavior should be that the port is ready for use when nova get's the external event, but maybe that is not possible from the neutron side, again see comments in the other bug. ** Affects: neutron Importance: Undecided Status: New -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to neutron. https://bugs.launchpad.net/bugs/1901707 Title: race condition on port binding vs instance being resumed for live- migrations Status in neutron: New Bug description: This is a separation from the discussion in this bug https://bugs.launchpad.net/neutron/+bug/1815989 There comment https://bugs.launchpad.net/neutron/+bug/1815989/comments/52 goes through in detail the flow on a Train deployment using neutron 15.1.0 (controller) and 15.3.0 (compute) and nova 20.4.0 There is a race condition where nova live-migration will wait for neutron to send the network-vif-plugged event but when nova receives that event the live migration is faster than the OVS l2 agent can bind the port on the destination compute node. This causes the RARP frames sent out to update the switches ARP tables to fail causing the instance to be completely unaccessible after a live migration unless these RARP frames are sent again or traffic is initiated egress from the instance. See Sean's comments after for the view from the Nova side. The correct behavior should be that the port is ready for use when nova get's the external event, but maybe that is not possible from the neutron side, again see comments in the other bug. To manage notifications about this bug go to: https://bugs.launchpad.net/neutron/+bug/1901707/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : [email protected] Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp
