---
fixes:
  - |
    Fix ProxySQL Galera configuration so that the backup writer
    node also serves read queries, instead of leaving it idle
    and sending all reads to the single remaining reader node.
    This is done by setting ``writer_is_also_reader`` to ``2``,
    which adds backup writer hostgroup nodes to the reader
    hostgroup while still excluding the active writer node. See
    the `ProxySQL documentation
    <https://proxysql.com/documentation/group-replication-configuration/>`__
    for details.
    `LP#2167037 <https://launchpad.net/bugs/2167037>`__