hadoop3.0-HA搭建，3節點。關閉防火墻 systemctl stop firewalld.service 關閉防火墻開機啟動 systemctl disable firewalld.service 禁用selinux安全 查看狀態：sestatus 臨時關閉: setenforce 0 永久關閉：vi /etc/sysconfig/selinux SELINUX=disabled