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.

Nested Class Summary

static 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