[ovs-discuss] active_backup failover issue

[Francois]

Hello OpenvSwitch!
I have 2 chassis with external connectivity, chassis-1 hosts port-1
and chassis-2 hosts port-2. SNAT is done through a gateway hosted on
chassis-1, and both chassis exchange BFD. There is no floating IP.

I see chassis-1 does not have any flow for tunnelling, which is logic
since it hosts the gateway. Traffic goes straight to the external port
of the chassis, which is fine.
I see however, chassis-2 having an extra flow:

 cookie=0x7a15360f, duration=4116.970s, table=37, n_packets=1471,
n_bytes=144158, priority=100,reg15=0x3,metadata=0x4
actions=load:0x4->NXM_NX_TUN_ID[0..23],set_field:0x3->tun_metadata0,move:NXM_NX_REG14[0..14]->NXM_NX_TUN_METADATA0[16..30],bundle(eth_src,0,active_backup,ofport,members:"ovn-chassi-0")

In my case I have only 2 chassis,  the bundle only contains a single member.

I am now killing the ovs process from chassis-1. Chassis-2 properly
detects that chassis-1 is dead, however packets going out are still
using this flow, and are not sent outside.

If I add a third chassis chassis-3, I see it monitors properly
chassis-1 and chassis-2, and the bundle members contain both chassis.
This case is fine and chassis-2 does the SNAT for chassis-3.

I am wondering if there is something wrong with my set-up. I would
expect that when chassis-1 dies and the gateway fails over to
chassis-2, traffic from port-2 actually goes out from chassis-2. It
should not be dropped (or be sent to the next chassis in the list,
although I did not try this). Any help would be very appreciated!

(this should be the master branch of ovn).
Thanks