Comment 6 for bug 1859145

Reviewed: https://review.opendev.org/705414
Committed: https://git.openstack.org/cgit/openstack/kolla-ansible/commit/?id=8acf5c132df02002e05a17c1754f5d79143a8d75
Submitter: Zuul
Branch: stable/train

commit 8acf5c132df02002e05a17c1754f5d79143a8d75
Author: Radosław Piliszek <email address hidden>
Date: Fri Jan 3 11:20:00 2020 +0100

    Fix multiple issues with MariaDB handling

    These affected both deploy (and reconfigure) and upgrade
    resulting in WSREP issues, failed deploys or need to
    recover the cluster.

    This patch makes sure k-a does not abruptly terminate
    nodes to break cluster.
    This is achieved by cleaner separation between stages
    (bootstrap, restart current, deploy new) and 3 phases
    for restarts (to keep the quorum).

    Upgrade actions, which operate on a healthy cluster,
    went to its section.

    Service restart was refactored.

    We no longer rely on the master/slave distinction as
    all nodes are masters in Galera.

    Backport includes also the:
    Followup on MariaDB handling fixes

    This fixes issues reported by Mark:
    - possible failure with 4-node cluster (however unlikely)
    - failure to stop all nodes from progressing when conditions are
      not valid (due to: "any_errors_fatal: False")

    Closes-bug: #1857908
    Closes-bug: #1859145
    Change-Id: I83600c69141714fc412df0976f49019a857655f5
    (cherry picked from commit 9f14ad651a9e6516d02c90d9eb0ec4b7a4702e7e)