org.apache.hadoop.dfs
Class DFSAdmin

java.lang.Object
  org.apache.hadoop.util.ToolBase
      org.apache.hadoop.fs.FsShell
          org.apache.hadoop.dfs.DFSAdmin

All Implemented Interfaces:

Configurable, Tool

public class DFSAdmin
extends FsShell

This class provides some DFS administrative access.

Author:

Dhruba Borthakur

Field Summary

Fields inherited from class org.apache.hadoop.fs.FsShell

fs

Fields inherited from class org.apache.hadoop.util.ToolBase

conf

Constructor Summary

DFSAdmin()
Construct a DFSAdmin object.

Method Summary

int	finalizeUpgrade() Command to ask the namenode to finalize previously performed upgrade.
static void	main(String[] argv) main() has some simple utility methods.
int	metaSave(String[] argv, int idx) Dumps DFS data structures into specified file.
void	printUsage(String cmd) Displays format of commands.
int	refreshNodes() Command to ask the namenode to reread the hosts and excluded hosts file.
void	report() Gives a report on how the FileSystem is doing.
int	run(String[] argv) run
void	setSafeMode(String[] argv, int idx) Safe mode maintenance command.

Methods inherited from class org.apache.hadoop.fs.FsShell

byteDesc, copy, delete, du, dus, init, limitDecimal, ls, mkdir, rename, setReplication

Methods inherited from class org.apache.hadoop.util.ToolBase

doMain, getConf, setConf

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DFSAdmin

public DFSAdmin()

Construct a DFSAdmin object.

Method Detail

report

public void report()
            throws IOException

Gives a report on how the FileSystem is doing.

Throws:

IOException - if the filesystem does not exist.

setSafeMode

public void setSafeMode(String[] argv,
                        int idx)
                 throws IOException

Safe mode maintenance command. Usage: java DFSAdmin -safemode [enter | leave | get]

Parameters:

argv - List of of command line parameters.

idx - The index of the command that is being processed.

Throws:

IOException - if the filesystem does not exist.

refreshNodes

public int refreshNodes()
                 throws IOException

Command to ask the namenode to reread the hosts and excluded hosts file. Usage: java DFSAdmin -refreshNodes

Throws:

IOException

finalizeUpgrade

public int finalizeUpgrade()
                    throws IOException

Command to ask the namenode to finalize previously performed upgrade. Usage: java DFSAdmin -finalizeUpgrade

Throws:

IOException

metaSave

public int metaSave(String[] argv,
                    int idx)
             throws IOException

Dumps DFS data structures into specified file. Usage: java DFSAdmin -metasave filename

Parameters:

argv - List of of command line parameters.

idx - The index of the command that is being processed.

Throws:

IOException - if an error accoured wile accessing the file or path.

printUsage

public void printUsage(String cmd)

Displays format of commands.

Overrides:

printUsage in class FsShell

Parameters:

cmd - The command that is being executed.

run

public int run(String[] argv)
        throws Exception

Description copied from class: FsShell

run

Specified by:

run in interface Tool

Overrides:

run in class FsShell

Parameters:

argv - The parameters passed to this program.

Returns:

0 on success, non zero on error.

Throws:

Exception - if the filesystem does not exist.

main

public static void main(String[] argv)
                 throws Exception

main() has some simple utility methods.

Parameters:

argv - Command line parameters.

Throws:

Exception - if the filesystem does not exist.