Comment 3 for bug 1856631

TRIAGED: confirmed.

The offending code is in hooks/percona_utils.py at:

303:
SQL_SST_USER_SETUP = ("GRANT {permissions} ON *.* "
                      "TO 'sstuser'@'localhost' IDENTIFIED BY '{password}'")

SQL_SST_USER_SETUP_IPV6 = ("GRANT {permissions} "
                           "ON *.* TO 'sstuser'@'ip6-localhost' IDENTIFIED "
                           "BY '{password}'")

1440:

def create_replication_user(slave_address, master_password):
    """ Create replication user (lp1776171)

    Grants access for MySQL asynchronous replication slave.

    :param slave_address: slave IP address
    :type slave_address: str
    :param master_password: replication password
    :type master_password: str
    :raises: OperationalError
    """
    m_helper = get_db_helper()
    try:
        m_helper.connect(password=m_helper.get_mysql_root_password())
    except OperationalError:
        log("Could not connect to db", level=DEBUG)
        return
    m_helper.execute(("GRANT REPLICATION SLAVE ON *.* TO ""'replication'@'{}' "
                      "IDENTIFIED BY '{}';").format(slave_address,
                                                    master_password))

FIX:

Replace grants with two SQL commands; one to create the user and one to grant the grant.