Hi all, I'm using ovs-ctl [Open vSwitch version: v2.11.2] to do ovs hot upgrading depending on the guide[https://docs.openvswitch.org/en/latest/intro/install/general/?highlight=hot%20upgrade#hot-upgrading]. Only userspace daemon should be upgraded in my situation, and ovsdb restart command was commented out. The upgrading workflow looks like this:
save_flows; #stop_ovsdb; #start_ovsdb; stop_forwarding; flow_restore_wait; start_forwarding; restore_flows; flow_restore_complete; While hot upgrading, the vxlan port belong to our bridge was deleted, and then was created few moments later. Once vxlan port was deleted, all packets send to vxlan port will be dropped, which is not expected. As long as I recongnize, vxlan port may be deleted in following three situation: 1. ovs-ctl execute "stop_forwarding"; 2. ovs-vswitchd "create ofproto"; 3. ovs-vswitchd "ofproto_type_run" In the first situation, if apply "kill -9 ovs-vswitchd" instead of gracefully exit by using "ovs-appctl -p pid exit", vxlan port will not be deleted. It's usefull, but then I was faced with the second situation. In the second situation, the function call chain in vswitchd is: “bridge_run -> bridge_reconfigure -> ofproto_create -> construct -> open_dpif_backer “ "open_dpif_backer" will compare the port name configured in ovsdb and the port get by netlink from kernel. ovs-vswitchd call "netdev_vport_get_dpif_port" to add the postfix "_sys_4789" for vxlan port before create port. Thus the name of vxlan port configrued in ovsdb is "vxlan", but in kernel it's "vxlan_sys_4789". vxlan_sys_4789 is considered as a unconfigured port and be deleted then. This seem unresonable. May I ask what is the consideration? I modified the comparison logic for vxlan type to avoid the second situation, also vxlan port added in "bridge_add_ports" is skipped. This cause the third situation. The function call chain in vswitchd is: “ bridge_run -> bridge_run__ -> ofproto_type_run -> type_run” "type_run" find out the vxlan_sys_4789 port is not in ofproto->backer->tnl_backers hmap(because "bridge_add_ports" is skipped), so netlink interface is called to create vxlan_sys_4789 port. Because the port "vxlan_sys_4789" is existed in kernel, ovs-vswitched will delete it. I'm confused about the behaviour ovs-vswitchd handle vxlan port and not sure all the above is designed by certain or not. The question is： - Is receate(delete first then create) vxlan port designed for any reason? Can this be avoided if no configurations was changed? - why ovs-vswitchd rename vxlan port to "vxlan_sys_4789", while remain other internal port its original name? - Is there a way to do ovs-vswitchd daemon hot upgrading without packet loss? Thanks a lot! Xiaowei Wang _______________________________________________ discuss mailing list disc...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
