Comment 2 for bug 1955498

$ more charm-neutron-openvswitch-1c9d98e6-61e0-11ec-9461-2f2de9716d4b.deferred
action: restart
policy_requestor_name: neutron-openvswitch
policy_requestor_type: charm
reason: Package update
service: openvswitch-switch
timestamp: 1640037572

* this timestamp translates to 2021-12-20T21:59:32

But we have a service restart at 21:59:31 per systemd:

$ systemctl status openvswitch-switch
● openvswitch-switch.service - Open vSwitch
     Loaded: loaded (/lib/systemd/system/openvswitch-switch.service; enabled; vendor preset: enabled)
     Active: active (exited) since Mon 2021-12-20 21:59:31 UTC; 16min ago
   Main PID: 51024 (code=exited, status=0/SUCCESS)
      Tasks: 0 (limit: 314572)
     Memory: 0B
     CGroup: /system.slice/openvswitch-switch.service

Dec 20 21:59:31 hostname systemd[1]: Starting Open vSwitch...
Dec 20 21:59:31 hostname systemd[1]: Finished Open vSwitch.

Before the restart, the ovs-vswitch.log also shows all interfaces and bridges being removed from the switch, which is why the outage lasts longer than a few seconds of switch restart. This seems to indicate to me that something greater than a service restart is happening during these Landscape system patches.