Comment 6 for bug 1744139

From the whiteboard, our current plan:

(TheJulia) Given the above information, the following courses of action seem to exist:

- Upgrade ironic-api and nova to the state on master branch. This is a departure from the "We will only upgrade ironic-conductor stance" and means we are not testing rolling-upgrade.
- Change grenade multinode to non-voting for the time being, while we continue to investigate.
   - (dtantsur) done, need to revert asap though
- Possibly fix negotiation logic in the client (patches in progress), and and then fix nova.
   - There is likely no way to even get the client in nova before mid-next week if we were to land changes and reqeust a release tomorrow (Friday) since it would be unlikely to actually be released until Monday.
   - This likely won't make g-r before Tuesday or Wednesday, and would then need to be landed in nova prior to being able to land code to negotiate. tl;dr this cannot be the only option.
   - Additional factor: This would mean tests can no longer expect that if nova is one version, that ironic must be another version with perfect compatability. I don't know if this would be an actual issue, however tempest plugins should have already been released, and ironic has already released its tempest plugin.
   - nova patch: "Ironic: negotiate microversion to allow downgrade to Pike": https://review.openstack.org/#/c/535786/
   - ironic patch (dependent on nova patch): "Rework upgrade to upgrade nova/ironic": https://review.openstack.org/535596