Scenario 2: One service at a time (HA version)

Pre-upgrade

Perform the necessary pre-upgrade steps.

Service upgrades

Upgrade each of your services. The following is a reasonable order in which to perform the upgrades on your controllers:

  1. MariaDB
  2. MongoDB
  3. Keystone
  4. Glance
  5. Cinder
  6. Heat
  7. Ceilometer
  8. Nova
  9. Neutron
  10. Horizon

Finally:

  1. Upgrade the compute hosts

Post-upgrade

Perform the necessary post-upgrade steps.