MariaDB
vi /etc/yum.repos.d/MariaDB.repo
# MariaDB 10.0 CentOS repository list – created 2015-08-12 10:59 UTC
# http://mariadb.org/mariadb/repositories/
[mariadb]
name=MariaDB Repository
baseurl = http://yum.mariadb.org/10.0/centos7-amd64
gpgkey=https://yum.mariadb.org/RPM-GPG-KEY-MariaDB
gpgcheck=1
安装MariaDB：
yum -y install MariaDB-server MariaDB-client
MongoDB 提供了centos yum安装方式。
参考：http://docs.mongodb.org/manual/tutorial/install-mongodb-on-red-hat/
pdf 手册：
http://docs.mongodb.org/manual/MongoDB-manual.pdf
vi /etc/yum.repos.d/mongodb-org-3.0.repo
[mongodb-org-3.0]
name=MongoDB Repository
baseurl=http://repo.mongodb.org/yum/redhat/$releasever/mongodb-org/3.0/x86_64/
gpgcheck=0
enabled=1
安装mongodb
yum install -y mongodb-org
首先为yum添加epel源：yum install epel-release回车
第二部：yum install varnish回车
