https://cloudinfrastructureservices.co.uk/how-to-setup-hadoop-cluster-multi-node-on-ubuntu/ -----host name 변경----------- sudo hostnamectl set-hostname masternode sudo hostnamectl set-hostname datanode1 sudo hostnamectl set-hostname datanode2 sudo hostnamectl set-hostname datanode3 -----all nodes-----------nano $HADOOP_HOME/etc/hadoop/hadoop-env.sh : line 54export JAVA_HOME=/usr/lib/jvm/java-1..