Safe backup of PXC / Galera cluster
Here's another option:

mysql&gt; SET GLOBAL wsrep_desync=1;
shell# &lt;execute backup&gt;
mysql&gt; SET GLOBAL wsrep_desync=0;


Just make sure to take the backup from the non-write node and no traffic is going through the node that's running XtraBackup. Test first on non-production systems.

https://www.percona.com/doc/percona-xtradb-cluster/5.6/wsrep-system-index.html#wsrep_desync