In CentOS 7 (and RHEL7 obviously) mariadb-server rpm is the default "mysql-server". The stock distro el7 mariadb-server rpm "provides" these:

1. rpm -qp mariadb-server-5.5.35-3.el7.x86_64.rpm --provides

config(mariadb-server) = 1:5.5.35-3.el7
libdaemon_example.so()(64bit)
mariadb-server = 1:5.5.35-3.el7
mariadb-server(x86-64) = 1:5.5.35-3.el7
mysql-compat-server = 1:5.5.35-3.el7
mysql-compat-server(x86-64) = 1:5.5.35-3.el7

So other software packaged for el7 requires/depends on either "mariadb-server" or "mysql-compat-server".

If one would like to use mariadb-galera-server rpms from mariadb.org instead, there's a problem with the "provides" in the rpms (both 5.5 and 10.0 versions for el7):

1. rpm -q -p MariaDB-Galera-10.0.14-centos7_0-x86_64-server.rpm --provides

MariaDB
MariaDB-Galera-server = 10.0.14-1.el7.centos
MariaDB-Galera-server(x86-64) = 10.0.14-1.el7.centos
MySQL
MySQL-server
config(MariaDB-Galera-server) = 10.0.14-1.el7.centos
config(mysql-server) = 10.0.14-1.el7.centos
msqlormysql
mysql-server
mysql-server = 10.0.14-1.el7.centos
mysql-server(x86-64) = 10.0.14-1.el7.centos

There's no "mariadb-server" nor "mysql-compat-server" being provided.. making it difficult to use mariadb-galera-server with some thirdparty software.

So please modify the "provides" of the mariadb.org mariadb-galera-server rpms to include "mariadb-server" and "mysql-compat-server". Thanks!