Hadoop Commands Guide

Overview

All hadoop commands are invoked by the bin/hadoop script. Running the hadoop script without any arguments prints the description for all commands.

Usage: hadoop [--config confdir] [--loglevel loglevel] [COMMAND] [GENERIC_OPTIONS] [COMMAND_OPTIONS]

--config confdir
Overwrites the default Configuration directory. Default is ${HADOOP_HOME}/conf.

hadoop checknative -a
Check all libraries are available.

hadoop classpath
hadoop classpath --glob

hadoop fs
This command is documented in the File System Shell Guide. It is a synonym for hdfs dfs
when HDFS is in use.

Usage: hadoop jar <jar> [mainClass] args...
Runs a jar file.
Use yarn jar
to launch YARN applications instead.

Usage: hadoop version
Prints the version.

hadoop daemonlog -getlevel <host:httpport> <classname>
hadoop daemonlog -setlevel <host:httpport> <classname> <level>

[root@hadoop hadoop-2.7.4]# hadoop daemonlog -getlevel 127.0.0.1:50070 org.apache.hadoop.hdfs.server.namenode.NameNode 
Connecting to http://127.0.0.1:50070/logLevel?log=org.apache.hadoop.hdfs.server.namenode.NameNode
Submitted Log Name: org.apache.hadoop.hdfs.server.namenode.NameNode
Log Class: org.apache.commons.logging.impl.Log4JLogger
Effective level: INFO