Keepalived+Nginx实现高可用（HA）
service iptables stop
chkconfig iptables off
setenforce 0
/etc/selinux/config
SELINUX=enforcing改为SELINUX=disabled
service iptables stop
chkconfig iptables off
setenforce 0
/etc/selinux/config
SELINUX=enforcing改为SELINUX=disabled
