Package org.apache.hadoop.hdfs.tools

Class DFSAdmin

java.lang.Object

org.apache.hadoop.conf.Configured

org.apache.hadoop.fs.FsShell

org.apache.hadoop.hdfs.tools.DFSAdmin

All Implemented Interfaces:

org.apache.hadoop.conf.Configurable, org.apache.hadoop.util.Tool

@Private
public class DFSAdmin
extends org.apache.hadoop.fs.FsShell

This class provides some DFS administrative access shell commands.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.fs.FsShell

org.apache.hadoop.fs.FsShell.Help, org.apache.hadoop.fs.FsShell.Usage

Field Summary

Fields

Modifier and Type	Field	Description
static java.lang.String[]	DFS_REPORT_ARGS

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

commandFactory

Constructor Summary

Constructors

Constructor	Description
DFSAdmin()	Construct a DFSAdmin object.
DFSAdmin(org.apache.hadoop.conf.Configuration conf)	Construct a DFSAdmin object.

Method Summary

Modifier and Type	Method	Description
void	allowSnapshot(java.lang.String[] argv)	Allow snapshot on a directory.
void	disallowSnapshot(java.lang.String[] argv)	Disallow snapshot on a directory.
int	fetchImage(java.lang.String[] argv, int idx)	Download the most recent fsimage from the name node, and save it to a local file in the given directory.
int	finalizeUpgrade()	Command to ask the namenode to finalize previously performed upgrade.
int	genericRefresh(java.lang.String[] argv, int i)
int	getBalancerBandwidth(java.lang.String[] argv, int idx)	Command to get balancer bandwidth for the given datanode.
protected org.apache.hadoop.hdfs.DistributedFileSystem	getDFS()
int	getUpgradeStatus()	Command to get the upgrade status of each namenode in the nameservice.
int	listOpenFiles(java.lang.String[] argv)	Command to list all the open files currently managed by NameNode.
static void	main(java.lang.String[] argv)	main() has some simple utility methods.
int	metaSave(java.lang.String[] argv, int idx)	Dumps DFS data structures into specified file.
int	printTopology()	Display each rack and the nodes assigned to that rack, as determined by the NameNode, in a hierarchical manner.
void	provisionSnapshotTrash(java.lang.String[] argv)	Provision trash root in a snapshottable directory.
int	reconfig(java.lang.String[] argv, int i)
int	refreshCallQueue()
int	refreshNodes()	Command to ask the namenode to reread the hosts and excluded hosts file.
int	refreshServiceAcl()	Refresh the authorization policy on the NameNode.
int	refreshSuperUserGroupsConfiguration()	refreshSuperUserGroupsConfiguration NameNode.
int	refreshUserToGroupsMappings()	Refresh the user-to-groups mappings on the NameNode.
void	report(java.lang.String[] argv, int i)	Gives a report on how the FileSystem is doing.
int	restoreFailedStorage(java.lang.String arg)	Command to enable/disable/check restoring of failed storage replicas in the namenode.
int	rollEdits()
int	run(java.lang.String[] argv)
int	saveNamespace(java.lang.String[] argv)	Command to ask the namenode to save the namespace.
int	setBalancerBandwidth(java.lang.String[] argv, int idx)	Command to ask the active namenode to set the balancer bandwidth.
void	setSafeMode(java.lang.String[] argv, int idx)	Safe mode maintenance command.
int	triggerBlockReport(java.lang.String[] argv)
int	upgrade(java.lang.String arg)	Upgrade command to get the status of upgrade or ask NameNode to finalize the previously performed upgrade.

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

close, getCurrentTrashDir, getCurrentTrashDir, getFS, getHelp, getTrash, getUsagePrefix, init, newShellInstance, registerCommands

Methods inherited from class org.apache.hadoop.conf.Configured

getConf, setConf

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.hadoop.conf.Configurable

getConf, setConf

Field Detail

DFS_REPORT_ARGS

public static final java.lang.String[] DFS_REPORT_ARGS

Constructor Detail

DFSAdmin

public DFSAdmin()

Construct a DFSAdmin object.

DFSAdmin

public DFSAdmin(org.apache.hadoop.conf.Configuration conf)

Construct a DFSAdmin object.

Method Detail

getDFS

protected org.apache.hadoop.hdfs.DistributedFileSystem getDFS()
                                                       throws java.io.IOException

Throws:

java.io.IOException

report

public void report(java.lang.String[] argv,
                   int i)
            throws java.io.IOException

Gives a report on how the FileSystem is doing.

Throws:

java.io.IOException - if the filesystem does not exist.

setSafeMode

public void setSafeMode(java.lang.String[] argv,
                        int idx)
                 throws java.io.IOException

Safe mode maintenance command. Usage: hdfs dfsadmin -safemode [enter | leave | get | wait | forceExit]

Parameters:

argv - List of of command line parameters.

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

Throws:

java.io.IOException - if the filesystem does not exist.

triggerBlockReport

public int triggerBlockReport(java.lang.String[] argv)
                       throws java.io.IOException

Throws:

java.io.IOException

allowSnapshot

public void allowSnapshot(java.lang.String[] argv)
                   throws java.io.IOException

Allow snapshot on a directory. Usage: hdfs dfsadmin -allowSnapshot snapshotDir

Parameters:

argv - List of of command line parameters.

Throws:

java.io.IOException

disallowSnapshot

public void disallowSnapshot(java.lang.String[] argv)
                      throws java.io.IOException

Disallow snapshot on a directory. Usage: hdfs dfsadmin -disallowSnapshot snapshotDir

Parameters:

argv - List of of command line parameters.

Throws:

java.io.IOException

provisionSnapshotTrash

public void provisionSnapshotTrash(java.lang.String[] argv)
                            throws java.io.IOException

Provision trash root in a snapshottable directory. Usage: hdfs dfsadmin -provisionSnapshotTrash snapshotDir hdfs dfsadmin -provisionSnapshotTrash -all

Parameters:

argv - List of of command line parameters.

Throws:

java.io.IOException

saveNamespace

public int saveNamespace(java.lang.String[] argv)
                  throws java.io.IOException

Command to ask the namenode to save the namespace. Usage: hdfs dfsadmin -saveNamespace

Throws:

java.io.IOException

See Also:

ClientProtocol.saveNamespace(long, long)

rollEdits

public int rollEdits()
              throws java.io.IOException

Throws:

java.io.IOException

restoreFailedStorage

public int restoreFailedStorage(java.lang.String arg)
                         throws java.io.IOException

Command to enable/disable/check restoring of failed storage replicas in the namenode. Usage: hdfs dfsadmin -restoreFailedStorage true|false|check

Throws:

java.io.IOException

See Also:

ClientProtocol.restoreFailedStorage(String arg)

refreshNodes

public int refreshNodes()
                 throws java.io.IOException

Command to ask the namenode to reread the hosts and excluded hosts file. Usage: hdfs dfsadmin -refreshNodes

Throws:

java.io.IOException

listOpenFiles

public int listOpenFiles(java.lang.String[] argv)
                  throws java.io.IOException

Command to list all the open files currently managed by NameNode. Usage: hdfs dfsadmin -listOpenFiles

Parameters:

argv -

Throws:

java.io.IOException

setBalancerBandwidth

public int setBalancerBandwidth(java.lang.String[] argv,
                                int idx)
                         throws java.io.IOException

Command to ask the active namenode to set the balancer bandwidth. Usage: hdfs dfsadmin -setBalancerBandwidth bandwidth

Parameters:

argv - List of of command line parameters.

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

Throws:

java.io.IOException

getBalancerBandwidth

public int getBalancerBandwidth(java.lang.String[] argv,
                                int idx)
                         throws java.io.IOException

Command to get balancer bandwidth for the given datanode. Usage: hdfs dfsadmin -getBalancerBandwidth <datanode_host:ipc_port>

Parameters:

argv - List of of command line parameters.

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

Throws:

java.io.IOException

fetchImage

public int fetchImage(java.lang.String[] argv,
                      int idx)
               throws java.io.IOException

Download the most recent fsimage from the name node, and save it to a local file in the given directory.

Parameters:

argv - List of of command line parameters.

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

Returns:

an exit code indicating success or failure.

Throws:

java.io.IOException

finalizeUpgrade

public int finalizeUpgrade()
                    throws java.io.IOException

Command to ask the namenode to finalize previously performed upgrade. Usage: hdfs dfsadmin -finalizeUpgrade

Throws:

java.io.IOException

getUpgradeStatus

public int getUpgradeStatus()
                     throws java.io.IOException

Command to get the upgrade status of each namenode in the nameservice. Usage: hdfs dfsadmin -upgrade query

Throws:

java.io.IOException

upgrade

public int upgrade(java.lang.String arg)
            throws java.io.IOException

Upgrade command to get the status of upgrade or ask NameNode to finalize the previously performed upgrade. Usage: hdfs dfsadmin -upgrade [query | finalize]

Throws:

java.io.IOException

metaSave

public int metaSave(java.lang.String[] argv,
                    int idx)
             throws java.io.IOException

Dumps DFS data structures into specified file. Usage: hdfs dfsadmin -metasave filename

Parameters:

argv - List of of command line parameters.

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

Throws:

java.io.IOException - if an error occurred while accessing the file or path.

printTopology

public int printTopology()
                  throws java.io.IOException

Display each rack and the nodes assigned to that rack, as determined by the NameNode, in a hierarchical manner. The nodes and racks are sorted alphabetically.

Throws:

java.io.IOException - If an error while getting datanode report

refreshServiceAcl

public int refreshServiceAcl()
                      throws java.io.IOException

Refresh the authorization policy on the NameNode.

Returns:

exitcode 0 on success, non-zero on failure

Throws:

java.io.IOException

refreshUserToGroupsMappings

public int refreshUserToGroupsMappings()
                                throws java.io.IOException

Refresh the user-to-groups mappings on the NameNode.

Returns:

exitcode 0 on success, non-zero on failure

Throws:

java.io.IOException

refreshSuperUserGroupsConfiguration

public int refreshSuperUserGroupsConfiguration()
                                        throws java.io.IOException

refreshSuperUserGroupsConfiguration NameNode.

Returns:

exitcode 0 on success, non-zero on failure

Throws:

java.io.IOException

refreshCallQueue

public int refreshCallQueue()
                     throws java.io.IOException

Throws:

java.io.IOException

reconfig

public int reconfig(java.lang.String[] argv,
                    int i)
             throws java.io.IOException,
                    java.lang.InterruptedException

Throws:

java.io.IOException

java.lang.InterruptedException

genericRefresh

public int genericRefresh(java.lang.String[] argv,
                          int i)
                   throws java.io.IOException

Throws:

java.io.IOException

run

public int run(java.lang.String[] argv)

Specified by:

run in interface org.apache.hadoop.util.Tool

Overrides:

run in class org.apache.hadoop.fs.FsShell

Parameters:

argv - The parameters passed to this program.

Returns:

0 on success, non zero on error.

main

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

main() has some simple utility methods.

Parameters:

argv - Command line parameters.

Throws:

java.lang.Exception - if the filesystem does not exist.