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  ---
  Hadoop Commands Guide
  ---
  ---
  ${maven.build.timestamp}

%{toc}

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] [COMMAND] [GENERIC_OPTIONS] [COMMAND_OPTIONS]>>>

   Hadoop has an option parsing framework that employs parsing generic
   options as well as running classes.

*-----------------------+---------------+
|| COMMAND_OPTION       || Description
*-----------------------+---------------+
| <<<--config confdir>>>| Overwrites the default Configuration directory.  Default is <<<${HADOOP_HOME}/conf>>>.
*-----------------------+---------------+
| GENERIC_OPTIONS       | The common set of options supported by multiple commands.
| COMMAND_OPTIONS       | Various commands with their options are described in the following sections. The commands have been grouped into User Commands and Administration Commands.
*-----------------------+---------------+

Generic Options

   The following options are supported by {{dfsadmin}}, {{fs}}, {{fsck}},
   {{job}} and {{fetchdt}}. Applications should implement 
   {{{../../api/org/apache/hadoop/util/Tool.html}Tool}} to support
   GenericOptions.

*------------------------------------------------+-----------------------------+
||            GENERIC_OPTION                     ||            Description
*------------------------------------------------+-----------------------------+
|<<<-conf \<configuration file\> >>>             | Specify an application
                                                 | configuration file.
*------------------------------------------------+-----------------------------+
|<<<-D \<property\>=\<value\> >>>                | Use value for given property.
*------------------------------------------------+-----------------------------+
|<<<-jt \<local\> or \<jobtracker:port\> >>>     | Specify a job tracker.
                                                 | Applies only to job.
*------------------------------------------------+-----------------------------+
|<<<-files \<comma separated list of files\> >>> | Specify comma separated files
                                                 | to be copied to the map
                                                 | reduce cluster.  Applies only
                                                 | to job.
*------------------------------------------------+-----------------------------+
|<<<-libjars \<comma seperated list of jars\> >>>| Specify comma separated jar
                                                 | files to include in the
                                                 | classpath. Applies only to
                                                 | job.
*------------------------------------------------+-----------------------------+
|<<<-archives \<comma separated list of archives\> >>> | Specify comma separated
                                                 | archives to be unarchived on
                                                 | the compute machines. Applies
                                                 | only to job.
*------------------------------------------------+-----------------------------+

User Commands

   Commands useful for users of a hadoop cluster.

* <<<archive>>>

   Creates a hadoop archive. More information can be found at
   {{{../../hadoop-mapreduce-client/hadoop-mapreduce-client-core/HadoopArchives.html}
   Hadoop Archives Guide}}.

* <<<distcp>>>

   Copy file or directories recursively. More information can be found at
   {{{../../hadoop-mapreduce-client/hadoop-mapreduce-client-core/DistCp.html}
   Hadoop DistCp Guide}}.

* <<<fs>>>

   Deprecated, use {{{../hadoop-hdfs/HDFSCommands.html#dfs}<<<hdfs dfs>>>}}
   instead.

* <<<fsck>>>

   Deprecated, use {{{../hadoop-hdfs/HDFSCommands.html#fsck}<<<hdfs fsck>>>}}
   instead.

* <<<fetchdt>>>

   Deprecated, use {{{../hadoop-hdfs/HDFSCommands.html#fetchdt}
   <<<hdfs fetchdt>>>}} instead.

* <<<jar>>>

   Runs a jar file. Users can bundle their Map Reduce code in a jar file and
   execute it using this command.

   Usage: <<<hadoop jar <jar> [mainClass] args...>>>

   The streaming jobs are run via this command. Examples can be referred from
   Streaming examples

   Word count example is also run using jar command. It can be referred from
   Wordcount example

* <<<job>>>

   Deprecated. Use
   {{{../../hadoop-mapreduce-client/hadoop-mapreduce-client-core/MapredCommands.html#job}
   <<<mapred job>>>}} instead.

* <<<pipes>>>

   Deprecated. Use
   {{{../../hadoop-mapreduce-client/hadoop-mapreduce-client-core/MapredCommands.html#pipes}
   <<<mapred pipes>>>}} instead.

* <<<queue>>>

   Deprecated. Use
   {{{../../hadoop-mapreduce-client/hadoop-mapreduce-client-core/MapredCommands.html#queue}
   <<<mapred queue>>>}} instead.

* <<<version>>>

   Prints the version.

   Usage: <<<hadoop version>>>

* <<<CLASSNAME>>>

   hadoop script can be used to invoke any class.

   Usage: <<<hadoop CLASSNAME>>>

   Runs the class named <<<CLASSNAME>>>.

* <<<classpath>>>

   Prints the class path needed to get the Hadoop jar and the required
   libraries.  If called without arguments, then prints the classpath set up by
   the command scripts, which is likely to contain wildcards in the classpath
   entries.  Additional options print the classpath after wildcard expansion or
   write the classpath into the manifest of a jar file.  The latter is useful in
   environments where wildcards cannot be used and the expanded classpath exceeds
   the maximum supported command line length.

   Usage: <<<hadoop classpath [--glob|--jar <path>|-h|--help]>>>

*-----------------+-----------------------------------------------------------+
|| COMMAND_OPTION || Description
*-----------------+-----------------------------------------------------------+
| --glob          | expand wildcards
*-----------------+-----------------------------------------------------------+
| --jar <path>    | write classpath as manifest in jar named <path>
*-----------------+-----------------------------------------------------------+
| -h, --help      | print help
*-----------------+-----------------------------------------------------------+

Administration Commands

   Commands useful for administrators of a hadoop cluster.

* <<<balancer>>>

   Deprecated, use {{{../hadoop-hdfs/HDFSCommands.html#balancer}
   <<<hdfs balancer>>>}} instead.

* <<<daemonlog>>>

   Get/Set the log level for each daemon.

   Usage: <<<hadoop daemonlog -getlevel <host:port> <name> >>>
   Usage: <<<hadoop daemonlog -setlevel <host:port> <name> <level> >>>

*------------------------------+-----------------------------------------------------------+
|| COMMAND_OPTION              || Description
*------------------------------+-----------------------------------------------------------+
| -getlevel <host:port> <name> | Prints the log level of the daemon running at
                               | <host:port>. This command internally connects
                               | to http://<host:port>/logLevel?log=<name>
*------------------------------+-----------------------------------------------------------+
|   -setlevel <host:port> <name> <level> | Sets the log level of the daemon
                               | running at <host:port>. This command internally
                               | connects to http://<host:port>/logLevel?log=<name>
*------------------------------+-----------------------------------------------------------+

* <<<datanode>>>

   Deprecated, use {{{../hadoop-hdfs/HDFSCommands.html#datanode}
   <<<hdfs datanode>>>}} instead.

* <<<dfsadmin>>>

   Deprecated, use {{{../hadoop-hdfs/HDFSCommands.html#dfsadmin}
   <<<hdfs dfsadmin>>>}} instead.

* <<<namenode>>>

   Deprecated, use {{{../hadoop-hdfs/HDFSCommands.html#namenode}
   <<<hdfs namenode>>>}} instead.

* <<<secondarynamenode>>>

   Deprecated, use {{{../hadoop-hdfs/HDFSCommands.html#secondarynamenode}
   <<<hdfs secondarynamenode>>>}} instead.