MasterFileSystem (Apache HBase 1.4.11 API)

java.lang.Object
- org.apache.hadoop.hbase.master.MasterFileSystem

```
@InterfaceAudience.Private
public class MasterFileSystem
extends Object
```
This class abstracts a bunch of operations the HMaster needs to interact with the underlying file system, including splitting log files, checking file system status, etc.

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`HBASE_DIR_PERMS` Parameter name for HBase instance root directory permission
`static String`	`HBASE_WAL_DIR_PERMS` Parameter name for HBase WAL directory permission

Constructor Summary

Constructors
Constructor and Description

MasterFileSystem(Server master, MasterServices services)

Constructors
Constructor and Description
`MasterFileSystem(Server master, MasterServices services)`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`archiveMetaLog(ServerName serverName)` For meta region open and closed normally on a server, it may leave some meta WAL in the server's wal dir.
`boolean`	`checkFileSystem()` Checks to see if the file system is still accessible.
`void`	`deleteFamilyFromFS(HRegionInfo region, byte[] familyName)`
`ClusterId`	`getClusterId()`
`org.apache.hadoop.conf.Configuration`	`getConfiguration()`
`org.apache.hadoop.fs.FileSystem`	`getFileSystem()`
`org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.SplitLogTask.RecoveryMode`	`getLogRecoveryMode()`
`org.apache.hadoop.fs.Path`	`getOldLogDir()` Get the directory where old logs go
`org.apache.hadoop.fs.Path`	`getRootDir()`
`org.apache.hadoop.fs.Path`	`getTempDir()`
`org.apache.hadoop.fs.FileSystem`	`getWALFileSystem()`
`org.apache.hadoop.fs.Path`	`getWALRootDir()`
`void`	`logFileSystemState(org.apache.commons.logging.Log log)`
`void`	`prepareLogReplay(ServerName serverName, Set<HRegionInfo> regions)` Mark regions in recovering state when distributedLogReplay are set true
`static void`	`setInfoFamilyCachingForMeta(HTableDescriptor metaDescriptor, boolean b)` Enable in memory caching for hbase:meta
`void`	`setLogRecoveryMode()` The function is used in SSH to set recovery mode based on configuration after all outstanding log split tasks drained.
`void`	`splitLog(ServerName serverName)`
`void`	`splitLog(Set<ServerName> serverNames)`
`void`	`splitLog(Set<ServerName> serverNames, org.apache.hadoop.fs.PathFilter filter)` This method is the base split method that splits WAL files matching a filter.
`void`	`splitMetaLog(ServerName serverName)` Specialized method to handle the splitting for meta WAL
`void`	`splitMetaLog(Set<ServerName> serverNames)` Specialized method to handle the splitting for meta WAL
`void`	`stop()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - HBASE_DIR_PERMS
```
public static final String HBASE_DIR_PERMS
```
    Parameter name for HBase instance root directory permission
    
    See Also:
    Constant Field Values
  - HBASE_WAL_DIR_PERMS
```
public static final String HBASE_WAL_DIR_PERMS
```
    Parameter name for HBase WAL directory permission
    
    See Also:
    Constant Field Values
- Constructor Detail
  - MasterFileSystem
```
public MasterFileSystem(Server master,
                MasterServices services)
                 throws IOException
```
    Throws:
    
    IOException
- Method Detail
  - getFileSystem
```
public org.apache.hadoop.fs.FileSystem getFileSystem()
```
  - getOldLogDir
```
public org.apache.hadoop.fs.Path getOldLogDir()
```
    Get the directory where old logs go
    
    Returns:
    the dir
  - checkFileSystem
```
public boolean checkFileSystem()
```
    Checks to see if the file system is still accessible. If not, sets closed
    
    Returns:
    false if file system is not available
  - getWALFileSystem
```
public org.apache.hadoop.fs.FileSystem getWALFileSystem()
```
  - getConfiguration
```
public org.apache.hadoop.conf.Configuration getConfiguration()
```
  - getRootDir
```
public org.apache.hadoop.fs.Path getRootDir()
```
    Returns:
    HBase root dir.
  - getWALRootDir
```
public org.apache.hadoop.fs.Path getWALRootDir()
```
    Returns:
    HBase root log dir.
  - getTempDir
```
public org.apache.hadoop.fs.Path getTempDir()
```
    Returns:
    HBase temp dir.
  - getClusterId
```
public ClusterId getClusterId()
```
    Returns:
    The unique identifier generated for this cluster
  - splitLog
```
public void splitLog(ServerName serverName)
              throws IOException
```
    Throws:
    
    IOException
  - splitMetaLog
```
public void splitMetaLog(ServerName serverName)
                  throws IOException
```
    Specialized method to handle the splitting for meta WAL
    
    Parameters:
    serverName -
    
    Throws:
    
    IOException
  - splitMetaLog
```
public void splitMetaLog(Set<ServerName> serverNames)
                  throws IOException
```
    Specialized method to handle the splitting for meta WAL
    
    Parameters:
    serverNames -
    
    Throws:
    
    IOException
  - prepareLogReplay
```
public void prepareLogReplay(ServerName serverName,
                    Set<HRegionInfo> regions)
                      throws IOException
```
    Mark regions in recovering state when distributedLogReplay are set true
    
    Parameters:
    serverName - Failed region server whose wals to be replayed
    regions - Set of regions to be recovered
    
    Throws:
    
    IOException
  - splitLog
```
public void splitLog(Set<ServerName> serverNames)
              throws IOException
```
    Throws:
    
    IOException
  - splitLog
```
public void splitLog(Set<ServerName> serverNames,
            org.apache.hadoop.fs.PathFilter filter)
              throws IOException
```
    This method is the base split method that splits WAL files matching a filter. Callers should pass the appropriate filter for meta and non-meta WALs.
    
    Parameters:
    serverNames - logs belonging to these servers will be split; this will rename the log directory out from under a soft-failed server
    filter -
    
    Throws:
    
    IOException
  - setInfoFamilyCachingForMeta
```
public static void setInfoFamilyCachingForMeta(HTableDescriptor metaDescriptor,
                               boolean b)
```
    Enable in memory caching for hbase:meta
  - deleteFamilyFromFS
```
public void deleteFamilyFromFS(HRegionInfo region,
                      byte[] familyName)
                        throws IOException
```
    Throws:
    
    IOException
  - stop
```
public void stop()
```
  - setLogRecoveryMode
```
public void setLogRecoveryMode()
                        throws IOException
```
    The function is used in SSH to set recovery mode based on configuration after all outstanding log split tasks drained.
    
    Throws:
    
    IOException
  - getLogRecoveryMode
```
public org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.SplitLogTask.RecoveryMode getLogRecoveryMode()
```
  - logFileSystemState
```
public void logFileSystemState(org.apache.commons.logging.Log log)
                        throws IOException
```
    Throws:
    
    IOException
  - archiveMetaLog
```
public void archiveMetaLog(ServerName serverName)
```
    For meta region open and closed normally on a server, it may leave some meta WAL in the server's wal dir. Since meta region is no long on this server, The SCP won't split those meta wals, just leaving them there. So deleting the wal dir will fail since the dir is not empty. Actually We can safely achive those meta log and Archiving the meta log and delete the dir.
    
    Parameters:
    serverName - the server to archive meta log

Class MasterFileSystem

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

HBASE_DIR_PERMS

HBASE_WAL_DIR_PERMS

Constructor Detail

MasterFileSystem

Method Detail

getFileSystem

getOldLogDir

checkFileSystem

getWALFileSystem

getConfiguration

getRootDir

getWALRootDir

getTempDir

getClusterId

splitLog

splitMetaLog

splitMetaLog

prepareLogReplay

splitLog

splitLog

setInfoFamilyCachingForMeta

deleteFamilyFromFS

stop

setLogRecoveryMode

getLogRecoveryMode

logFileSystemState

archiveMetaLog