---
upgrade:
  - During upgrades, container and service restarts for the mariadb/galera
    cluster were being triggered multiple times and causing the cluster to
    become unstable and often unrecoverable. This situation has been improved
    immensely, and we now have tight control such that restarts of the galera
    containers only need to happen once, and are done so in a controlled,
    predictable and repeatable way.