HFileSystem (Apache HBase 1.1.7 API)

java.lang.Object
- org.apache.hadoop.conf.Configured
- - org.apache.hadoop.fs.FileSystem
  - - org.apache.hadoop.fs.FilterFileSystem
    - - org.apache.hadoop.hbase.fs.HFileSystem

All Implemented Interfaces:

Closeable, AutoCloseable, org.apache.hadoop.conf.Configurable
```
public class HFileSystem
extends org.apache.hadoop.fs.FilterFileSystem
```
An encapsulation for the FileSystem object that hbase uses to access data. This class allows the flexibility of using separate filesystem objects for reading and writing hfiles and wals. In future, if we want to make wals be in a different filesystem, this is the place to make it happen.

Nested Class Summary
- Nested classes/interfaces inherited from class org.apache.hadoop.fs.FileSystem
  org.apache.hadoop.fs.FileSystem.Statistics

Field Summary

Fields
Modifier and Type Field and Description

static org.apache.commons.logging.Log LOG
- Fields inherited from class org.apache.hadoop.fs.FilterFileSystem
  fs, swapScheme
- Fields inherited from class org.apache.hadoop.fs.FileSystem
  DEFAULT_FS, FS_DEFAULT_NAME_KEY, SHUTDOWN_HOOK_PRIORITY, statistics

Fields
Modifier and Type	Field and Description
`static org.apache.commons.logging.Log`	`LOG`

Constructor Summary

Constructors
Constructor and Description
`HFileSystem(org.apache.hadoop.conf.Configuration conf, boolean useHBaseChecksum)` Create a FileSystem object for HBase regionservers.
`HFileSystem(org.apache.hadoop.fs.FileSystem fs)` Wrap a FileSystem object within a HFileSystem.

Method Summary

Methods
Modifier and Type	Method and Description
`static boolean`	`addLocationsOrderInterceptor(org.apache.hadoop.conf.Configuration conf)`
`void`	`close()` Close this filesystem object
`org.apache.hadoop.fs.FSDataOutputStream`	`createNonRecursive(org.apache.hadoop.fs.Path f, boolean overwrite, int bufferSize, short replication, long blockSize, org.apache.hadoop.util.Progressable progress)` The org.apache.hadoop.fs.FilterFileSystem does not yet support createNonRecursive.
`static org.apache.hadoop.fs.FileSystem`	`get(org.apache.hadoop.conf.Configuration conf)` Create a new HFileSystem object, similar to FileSystem.get().
`org.apache.hadoop.fs.FileSystem`	`getBackingFs()` Returns the underlying filesystem
`static org.apache.hadoop.fs.FileSystem`	`getLocalFs(org.apache.hadoop.conf.Configuration conf)` Wrap a LocalFileSystem within a HFileSystem.
`org.apache.hadoop.fs.FileSystem`	`getNoChecksumFs()` Returns the filesystem that is specially setup for doing reads from storage.
`boolean`	`useHBaseChecksum()` Are we verifying checksums in HBase?

Methods inherited from class org.apache.hadoop.fs.FilterFileSystem
append, canonicalizeUri, checkPath, completeLocalOutput, concat, copyFromLocalFile, copyFromLocalFile, copyFromLocalFile, copyToLocalFile, create, createNonRecursive, createSnapshot, createSymlink, delete, deleteSnapshot, getAclStatus, getCanonicalUri, getChildFileSystems, getConf, getDefaultBlockSize, getDefaultBlockSize, getDefaultReplication, getDefaultReplication, getFileBlockLocations, getFileChecksum, getFileChecksum, getFileLinkStatus, getFileStatus, getHomeDirectory, getInitialWorkingDirectory, getLinkTarget, getRawFileSystem, getServerDefaults, getServerDefaults, getStatus, getUri, getUsed, getWorkingDirectory, getXAttr, getXAttrs, getXAttrs, initialize, listCorruptFileBlocks, listLocatedStatus, listStatus, listXAttrs, makeQualified, mkdirs, modifyAclEntries, open, primitiveCreate, primitiveMkdir, removeAcl, removeAclEntries, removeDefaultAcl, removeXAttr, rename, renameSnapshot, resolveLink, resolvePath, setAcl, setOwner, setPermission, setReplication, setTimes, setVerifyChecksum, setWorkingDirectory, setWriteChecksum, setXAttr, setXAttr, startLocalOutput, supportsSymlinks

Methods inherited from class org.apache.hadoop.fs.FileSystem
addDelegationTokens, append, append, areSymlinksEnabled, cancelDeleteOnExit, clearStatistics, closeAll, closeAllForUGI, copyFromLocalFile, copyToLocalFile, copyToLocalFile, create, create, create, create, create, create, create, create, create, create, create, create, createNewFile, createNonRecursive, createSnapshot, delete, deleteOnExit, enableSymlinks, exists, fixRelativePart, get, get, getAllStatistics, getBlockSize, getCanonicalServiceName, getContentSummary, getDefaultPort, getDefaultUri, getDelegationToken, getFileBlockLocations, getFileSystemClass, getFSofPath, getLength, getLocal, getName, getNamed, getReplication, getScheme, getStatistics, getStatistics, getStatus, globStatus, globStatus, isDirectory, isFile, listFiles, listLocatedStatus, listStatus, listStatus, listStatus, mkdirs, mkdirs, moveFromLocalFile, moveFromLocalFile, moveToLocalFile, newInstance, newInstance, newInstance, newInstanceLocal, open, primitiveMkdir, printStatistics, processDeleteOnExit, rename, setDefaultUri, setDefaultUri

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

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
```
- Constructor Detail
  - HFileSystem
```
public HFileSystem(org.apache.hadoop.conf.Configuration conf,
           boolean useHBaseChecksum)
            throws IOException
```
    Create a FileSystem object for HBase regionservers.
    
    Parameters:
    conf - The configuration to be used for the filesystem
    useHBaseChecksum - if true, then use checksum verfication in hbase, otherwise delegate checksum verification to the FileSystem.
    
    Throws:
    
    IOException
  - HFileSystem
```
public HFileSystem(org.apache.hadoop.fs.FileSystem fs)
```
    Wrap a FileSystem object within a HFileSystem. The noChecksumFs and writefs are both set to be the same specified fs. Do not verify hbase-checksums while reading data from filesystem.
    
    Parameters:
    fs - Set the noChecksumFs and writeFs to this specified filesystem.
- Method Detail
  - getNoChecksumFs
```
public org.apache.hadoop.fs.FileSystem getNoChecksumFs()
```
    Returns the filesystem that is specially setup for doing reads from storage. This object avoids doing checksum verifications for reads.
    
    Returns:
    The FileSystem object that can be used to read data from files.
  - getBackingFs
```
public org.apache.hadoop.fs.FileSystem getBackingFs()
                                             throws IOException
```
    Returns the underlying filesystem
    
    Returns:
    The underlying FileSystem for this FilterFileSystem object.
    
    Throws:
    
    IOException
  - useHBaseChecksum
```
public boolean useHBaseChecksum()
```
    Are we verifying checksums in HBase?
    
    Returns:
    True, if hbase is configured to verify checksums, otherwise false.
  - close
```
public void close()
           throws IOException
```
    Close this filesystem object
    
    Specified by:
    
    close in interface Closeable
    
    Specified by:
    
    close in interface AutoCloseable
    
    Overrides:
    
    close in class org.apache.hadoop.fs.FilterFileSystem
    
    Throws:
    
    IOException
  - addLocationsOrderInterceptor
```
public static boolean addLocationsOrderInterceptor(org.apache.hadoop.conf.Configuration conf)
                                            throws IOException
```
    Throws:
    
    IOException
  - get
```
public static org.apache.hadoop.fs.FileSystem get(org.apache.hadoop.conf.Configuration conf)
                                           throws IOException
```
    Create a new HFileSystem object, similar to FileSystem.get(). This returns a filesystem object that avoids checksum verification in the filesystem for hfileblock-reads. For these blocks, checksum verification is done by HBase.
    
    Throws:
    
    IOException
  - getLocalFs
```
public static org.apache.hadoop.fs.FileSystem getLocalFs(org.apache.hadoop.conf.Configuration conf)
                                                  throws IOException
```
    Wrap a LocalFileSystem within a HFileSystem.
    
    Throws:
    
    IOException
  - createNonRecursive
```
public org.apache.hadoop.fs.FSDataOutputStream createNonRecursive(org.apache.hadoop.fs.Path f,
                                                         boolean overwrite,
                                                         int bufferSize,
                                                         short replication,
                                                         long blockSize,
                                                         org.apache.hadoop.util.Progressable progress)
                                                           throws IOException
```
    The org.apache.hadoop.fs.FilterFileSystem does not yet support createNonRecursive. This is a hadoop bug and when it is fixed in Hadoop, this definition will go away.
    
    Overrides:
    
    createNonRecursive in class org.apache.hadoop.fs.FileSystem
    
    Throws:
    
    IOException

Class HFileSystem

Nested Class Summary

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

Field Summary

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

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

Constructor Summary

Method Summary

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

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

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

Methods inherited from class java.lang.Object

Field Detail

LOG

Constructor Detail

HFileSystem

HFileSystem

Method Detail

getNoChecksumFs

getBackingFs

useHBaseChecksum

close

addLocationsOrderInterceptor

get

getLocalFs

createNonRecursive