[kolla] Best way to restart controllers

Hi all,

We are looking for the best way to process system upgrades on our controller nodes and especially the best way to restart them (we have 3 controllers nodes with routers ha). If we just restart them one by one (waiting long time between each), we have already seen rabbitmq cluster errors (needing a complete restart of rabbitmq). With a kolla stop, a restart and a kolla deploy, some docker containers are restarted on others nodes.

The administration guides describes how to add or remove a node but not this simple case. How do you proceed securely?

Thanks for all, Yves