[ovs-discuss] equal generation_id

[Ben Pfaff]

On Thu, Aug 09, 2018 at 02:09:22PM -0400, Logan Blyth wrote:
> Hello,
> I am testing a master / slave controller configuration and have run into a
> question. The spec says that the function used to determine if a
> generation_id is stale or not is
> distance(GEN_ID_X, cached_generation_id) < 0)
> what is supposed to happen if distance = 0?
> 
> In my testing wireshark showed a loop of role_request, role_reply messages
> to each controller.
> 'ovs-vsctl list controller' showed one controller as slave and one a
> master, but I didn't see the corresponding message sent across the wire, so
> both of my controllers thought they became master.
> 
> I apologize if this issue has been raised before on the list, and I missed
> it. I did search the FAQ for OFPT_ROLE_REQUEST and MASTER but didn't find
> anything that covered this.

It looks like OVS implements exactly the algorithm from the spec.