Package org.apache.hadoop.hdfs.tools

Class DFSck

java.lang.Object

org.apache.hadoop.conf.Configured

org.apache.hadoop.hdfs.tools.DFSck

All Implemented Interfaces:

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

@Private
public class DFSck
extends org.apache.hadoop.conf.Configured
implements org.apache.hadoop.util.Tool

This class provides rudimentary checking of DFS volumes for errors and sub-optimal conditions.

The tool scans all files and directories, starting from an indicated root path. The following abnormal conditions are detected and handled:

• files with blocks that are completely missing from all datanodes.
  In this case the tool can perform one of the following actions:
  • move corrupted files to /lost+found directory on DFS (NamenodeFsck.doMove). Remaining data blocks are saved as a block chains, representing longest consecutive series of valid blocks.
  • delete corrupted files (NamenodeFsck.doDelete)
• detect files with under-replicated or over-replicated blocks

Additionally, the tool collects a detailed overall DFS statistics, and optionally can print detailed statistics on block locations and replication factors of each file. The tool also provides and option to filter open files during the scan.

Constructor Summary

Constructors

Constructor	Description
DFSck(org.apache.hadoop.conf.Configuration conf)	Filesystem checker.
DFSck(org.apache.hadoop.conf.Configuration conf, java.io.PrintStream out)

Method Summary

Modifier and Type	Method	Description
static void	main(java.lang.String[] args)
int	run(java.lang.String[] args)

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

Constructor Detail

DFSck

public DFSck(org.apache.hadoop.conf.Configuration conf)
      throws java.io.IOException

Filesystem checker.

Parameters:

conf - current Configuration

Throws:

java.io.IOException

DFSck

public DFSck(org.apache.hadoop.conf.Configuration conf,
             java.io.PrintStream out)
      throws java.io.IOException

Throws:

java.io.IOException

Method Detail

run

public int run(java.lang.String[] args)
        throws java.io.IOException

Specified by:

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

Throws:

java.io.IOException

main

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

Throws:

java.lang.Exception