Follow guide available at iUS

systemctl stop mariadb
yum replace mariadb-server --replace-with mariadb101u-server
mkdir /etc/systemd/system/mariadb.service.d
/etc/systemd/system/mariadb.service.d/limit.conf
[Service]
LimitNOFILE=320000
systemctl start mariadb
mysqlcheck --no-defaults --check-upgrade --all-databases --auto-repair --write-binlog
mysqlcheck --no-defaults --all-databases --fix-db-names --fix-table-names --write-binlog -p
mysqlcheck --no-defaults --check-upgrade --auto-repair --databases mysql -p
mysql_upgrade