Galera can't perform SST in 10.2.13 if systemd in use due to timeout at startup

The second node can't join the first node because SST will get killed by systemd after the default timeout hits.

systemctl show mariadb.service | grep Timeout will show timeout set to 1m 30s for startup, but an SST can last hours with large dataset and/or slow disks and/or slow networks.

In fact, it is common for an SST to take several hours in production.

Setting TimeoutSec=0 under Services in the mariadb.service config file under systemd fixes the problem.

Right now, it is impossible to deploy Galera Cluster under 10.2.13 and CentOS 7 unless the above workaround is in place.