echo $HOSTNAME > /etc/hostname
hostnamectl set-hostname $HOSTNAME
vi /etc/hosts
# localhost 는 자동으로 입력되는 값, 보통 변경하지 않는다.
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
# IP $HOST $HOST.DOMAIN $HOST_ALIAS 형식으로 추가한다
172.17.0.11 master1.hadoop.com master1 masternode1 repository
172.17.0.12 master2.hadoop.com master2 masternode2
172.17.0.33 master3.hadoop.com master3 masternode3 dbms