vi /etc/yum.repos.d/cassandra.repo

[cassandra]
name=Apache Cassandra
baseurl=http://www.apache.org/dist/cassandra/redhat/311x/
gpgcheck=1
repo_gpgcheck=1
gpgkey=http://www.apache.org/dist/cassandra/KEYS

yum install cassandra

安装完成后启动服务
service cassandra start

与之对应的停止服务的命令为
sudo service cassandra stop

设置cassandra为自动启动
chkconfig cassandra on   

使用cqlsh进入Cassandra