I am new in learning Hadoop. And I meet some problems in its configuration. Before it, I finished the configuration of JAVA, SSH, core-site.xml, hdfs-site.xml and hadoop-env.sh. Please tell me how can I solve it. Thank you very much.
root@host1-virtual-machine:/home/host1/usr/hadoop-3.2.1# sbin/start-all.sh
Starting namenodes on [localhost]
ERROR: Attempting to operate on hdfs namenode as root
ERROR: but there is no HDFS_NAMENODE_USER defined. Aborting operation.
Starting datanodes
ERROR: Attempting to operate on hdfs datanode as root
ERROR: but there is no HDFS_DATANODE_USER defined. Aborting operation.
Starting secondary namenodes [host1-virtual-machine]
ERROR: Attempting to operate on hdfs secondarynamenode as root
ERROR: but there is no HDFS_SECONDARYNAMENODE_USER defined. Aborting operation.
2020-02-12 13:19:37,322 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Starting resourcemanager
ERROR: Attempting to operate on yarn resourcemanager as root
ERROR: but there is no YARN_RESOURCEMANAGER_USER defined. Aborting operation.
Starting nodemanagers
ERROR: Attempting to operate on yarn nodemanager as root
ERROR: but there is no YARN_NODEMANAGER_USER defined. Aborting operation.
After I add 5 lines into hadoop-env.sh, it warns the following:
Starting namenodes on [localhost]
localhost: root@localhost: Permission denied (publickey,password).
Starting datanodes
localhost: root@localhost: Permission denied (publickey,password).
Starting secondary namenodes [host1-virtual-machine]
host1-virtual-machine: root@host1-virtual-machine: Permission denied (publickey,password).
2020-02-12 20:26:27,702 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Starting resourcemanager
Starting nodemanagers
localhost: root@localhost: Permission denied (publickey,password).
The reason for this issue is use of different user in installation and for starting the service. You can define the users as root in hadoop-env.sh as below:
export HDFS_NAMENODE_USER=root
export HDFS_DATANODE_USER=root
export HDFS_SECONDARYNAMENODE_USER=root
export YARN_RESOURCEMANAGER_USER=root
export YARN_NODEMANAGER_USER=root
Hope this helps