org.apache.hadoop.dfs
Class NamenodeFsck

java.lang.Object
  org.apache.hadoop.dfs.NamenodeFsck

public class NamenodeFsck
extends Object

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:
  • none (FIXING_NONE)
  • move corrupted files to /lost+found directory on DFS (FIXING_MOVE). Remaining data blocks are saved as a block chains, representing longest consecutive series of valid blocks.
  • delete corrupted files (FIXING_DELETE)
• 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.

Author:

Andrzej Bialecki

Nested Class Summary

class

NamenodeFsck.FsckResult FsckResult of checking, plus overall DFS statistics.

Field Summary

static int	FIXING_DELETE Delete corrupted files.
static int	FIXING_MOVE Move corrupted files to /lost+found .
static int	FIXING_NONE Don't attempt any fixing .
static org.apache.commons.logging.Log	LOG

Constructor Summary

NamenodeFsck(Configuration conf, NameNode nn, Map<String,String[]> pmap, javax.servlet.http.HttpServletResponse response)
Filesystem checker.

Method Summary

void	fsck() Check files on DFS, starting from the indicated path.
int	run(String[] args)

Methods inherited from class java.lang.Object

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

Field Detail

LOG

public static final org.apache.commons.logging.Log LOG

FIXING_NONE

public static final int FIXING_NONE

Don't attempt any fixing .

See Also:

Constant Field Values

FIXING_MOVE

public static final int FIXING_MOVE

Move corrupted files to /lost+found .

See Also:

Constant Field Values

FIXING_DELETE

public static final int FIXING_DELETE

Delete corrupted files.

See Also:

Constant Field Values

Constructor Detail

NamenodeFsck

public NamenodeFsck(Configuration conf,
                    NameNode nn,
                    Map<String,String[]> pmap,
                    javax.servlet.http.HttpServletResponse response)
             throws IOException

Filesystem checker.

Parameters:

conf - configuration (namenode config)

nn - namenode that this fsck is going to use

pmap - key=value[] map that is passed to the http servlet as url parameters

response - the object into which this servelet writes the url contents

Throws:

IOException

Method Detail

fsck

public void fsck()
          throws IOException

Check files on DFS, starting from the indicated path.

Throws:

Exception

IOException

run

public int run(String[] args)
        throws Exception

Parameters:

args -

Throws:

Exception