There were other changes after that moving code around the tree, etc.
I *think* the intention was for an operator to be able to control auto-scheduling of routers during upgrades, for example when they manually move routers off an agent in order to bring the controller node down. But I don't remember exactly as it's been a looong time, even for me. I just don't believe the intent was to ever fix a 'dangling' router, it was to just leave things where they were for a period of time. That doesn't mean it's not confusing.
Oleg might remember as we was around those days as well and he fixed the last bug :)
So some of the context of this option is gone, but I can tell you it was originally introduced in the Quantum days in 2013 - https:/ /review. opendev. org/c/openstack /neutron/ +/21175
There were other changes after that moving code around the tree, etc.
I *think* the intention was for an operator to be able to control auto-scheduling of routers during upgrades, for example when they manually move routers off an agent in order to bring the controller node down. But I don't remember exactly as it's been a looong time, even for me. I just don't believe the intent was to ever fix a 'dangling' router, it was to just leave things where they were for a period of time. That doesn't mean it's not confusing.
Oleg might remember as we was around those days as well and he fixed the last bug :)