Current debian stretch use mariadb 10.1.26 which integrates
a backup tool call 'MariaDB Backup' [1]. It is based on
Percona XtraBackup and support full backup capability for
MariaDB Server that includes encrypted and compressed data.
This patch also fixs muti-node deployment failed on Debian
aarch64. Percona's repo has no XtraBackup package for Debian
aarch64. In such case we can use MariaDB builtin backup tool
'MariaDB Backup'.
[1] https://mariadb.com/kb/en/library/mariadb-backup-overview/
Change-Id: I7271d3f93b41d4839670a2c4a358744333411cd7
2f903bf4e4