org.apache.hadoop.hdfs.server.common

类 Storage

java.lang.Object

org.apache.hadoop.hdfs.server.common.StorageInfo

org.apache.hadoop.hdfs.server.common.Storage

直接已知子类:

DataStorage, FSImage

public abstract class Storage
extends StorageInfo

Storage information file.

Local storage information is stored in a separate file VERSION. It contains type of the node, the storage layout version, the namespace id, and the fs state creation time.

Local storage can reside in multiple directories. Each directory should contain the same VERSION file as the others. During startup Hadoop servers (name-node and data-nodes) read their local storage information from them.

The servers hold a lock for each storage directory while they run so that other nodes were not able to startup sharing the same storage. The locks are released when the servers stop (normally or abnormally).

嵌套类概要

嵌套类

限定符和类型	类和说明
class	Storage.StorageDirectory One of the storage directories.
static interface	Storage.StorageDirType An interface to denote storage directory type Implementations can define a type for storage directory by implementing this interface.
static class	Storage.StorageState

字段概要

字段

限定符和类型	字段和说明
protected static int	LAST_PRE_UPGRADE_LAYOUT_VERSION
protected static String	LAST_UPGRADABLE_HADOOP_VERSION
static int	LAST_UPGRADABLE_LAYOUT_VERSION
static int[]	LAYOUT_VERSIONS_203 Layout versions of 203 release
static org.apache.commons.logging.Log	LOG
static int	PRE_GENERATIONSTAMP_LAYOUT_VERSION
static String	STORAGE_DIR_CURRENT
protected static String	STORAGE_FILE_VERSION
protected List<Storage.StorageDirectory>	storageDirs

从类继承的字段 org.apache.hadoop.hdfs.server.common.StorageInfo

cTime, layoutVersion, namespaceID

构造器概要

构造器

限定符	构造器和说明
protected	Storage(HdfsConstants.NodeType type) Create empty storage info of the specified type
protected	Storage(HdfsConstants.NodeType type, int nsID, long cT)
protected	Storage(HdfsConstants.NodeType type, StorageInfo storageInfo)

方法概要

方法

限定符和类型	方法和说明
protected void	addStorageDir(Storage.StorageDirectory sd)
protected static void	checkVersionUpgradable(int oldVersion) Checks if the upgrade from the given old version is supported.
protected abstract void	corruptPreUpgradeStorage(File rootDir)
protected static void	deleteDir(File dir)
Iterator<Storage.StorageDirectory>	dirIterator() Return default iterator This iterator returns all entires of storageDirs
Iterator<Storage.StorageDirectory>	dirIterator(Storage.StorageDirType dirType) Return iterator based on Storage Directory Type This iterator selects entires of storageDirs of type dirType and returns them via the Iterator
protected void	getFields(Properties props, Storage.StorageDirectory sd) Get common storage fields.
int	getNumStorageDirs()
static String	getRegistrationID(StorageInfo storage)
Storage.StorageDirectory	getStorageDir(int idx)
static boolean	is203LayoutVersion(int layoutVersion)
abstract boolean	isConversionNeeded(Storage.StorageDirectory sd)
boolean	isLockSupported(int idx) Check whether underlying file system supports file locking.
static void	rename(File from, File to)
protected void	setFields(Properties props, Storage.StorageDirectory sd) Set common storage fields.
void	unlockAll() Unlock all storage directories.
void	writeAll() Write all data storage files.
protected void	writeCorruptedData(RandomAccessFile file)

从类继承的方法 org.apache.hadoop.hdfs.server.common.StorageInfo

getCTime, getLayoutVersion, getNamespaceID, setStorageInfo

从类继承的方法 java.lang.Object

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

字段详细资料

LOG

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

LAST_PRE_UPGRADE_LAYOUT_VERSION

protected static final int LAST_PRE_UPGRADE_LAYOUT_VERSION

另请参阅:

常量字段值

LAST_UPGRADABLE_LAYOUT_VERSION

public static final int LAST_UPGRADABLE_LAYOUT_VERSION

另请参阅:

常量字段值

LAST_UPGRADABLE_HADOOP_VERSION

protected static final String LAST_UPGRADABLE_HADOOP_VERSION

另请参阅:

常量字段值

PRE_GENERATIONSTAMP_LAYOUT_VERSION

public static final int PRE_GENERATIONSTAMP_LAYOUT_VERSION

另请参阅:

常量字段值

LAYOUT_VERSIONS_203

public static final int[] LAYOUT_VERSIONS_203

Layout versions of 203 release

STORAGE_FILE_VERSION

protected static final String STORAGE_FILE_VERSION

另请参阅:

常量字段值

STORAGE_DIR_CURRENT

public static final String STORAGE_DIR_CURRENT

另请参阅:

常量字段值

storageDirs

protected List<Storage.StorageDirectory> storageDirs

构造器详细资料

Storage

protected Storage(HdfsConstants.NodeType type)

Create empty storage info of the specified type

Storage

protected Storage(HdfsConstants.NodeType type,
       int nsID,
       long cT)

Storage

protected Storage(HdfsConstants.NodeType type,
       StorageInfo storageInfo)

方法详细资料

dirIterator

public Iterator<Storage.StorageDirectory> dirIterator()

Return default iterator This iterator returns all entires of storageDirs

dirIterator

public Iterator<Storage.StorageDirectory> dirIterator(Storage.StorageDirType dirType)

Return iterator based on Storage Directory Type This iterator selects entires of storageDirs of type dirType and returns them via the Iterator

getNumStorageDirs

public int getNumStorageDirs()

getStorageDir

public Storage.StorageDirectory getStorageDir(int idx)

addStorageDir

protected void addStorageDir(Storage.StorageDirectory sd)

isConversionNeeded

public abstract boolean isConversionNeeded(Storage.StorageDirectory sd)
                                    throws IOException

抛出:

IOException

checkVersionUpgradable

protected static void checkVersionUpgradable(int oldVersion)
                                      throws IOException

Checks if the upgrade from the given old version is supported. If no upgrade is supported, it throws IncorrectVersionException.

参数:

oldVersion -

抛出:

IOException

getFields

protected void getFields(Properties props,
             Storage.StorageDirectory sd)
                  throws IOException

Get common storage fields. Should be overloaded if additional fields need to be get.

参数:

props -

抛出:

IOException

setFields

protected void setFields(Properties props,
             Storage.StorageDirectory sd)
                  throws IOException

Set common storage fields. Should be overloaded if additional fields need to be set.

参数:

props -

抛出:

IOException

rename

public static void rename(File from,
          File to)
                   throws IOException

抛出:

IOException

deleteDir

protected static void deleteDir(File dir)
                         throws IOException

抛出:

IOException

writeAll

public void writeAll()
              throws IOException

Write all data storage files.

抛出:

IOException

unlockAll

public void unlockAll()
               throws IOException

Unlock all storage directories.

抛出:

IOException

isLockSupported

public boolean isLockSupported(int idx)
                        throws IOException

Check whether underlying file system supports file locking.

返回:

true if exclusive locks are supported or false otherwise.

抛出:

IOException

另请参阅:

Storage.StorageDirectory.lock()

getRegistrationID

public static String getRegistrationID(StorageInfo storage)

corruptPreUpgradeStorage

protected abstract void corruptPreUpgradeStorage(File rootDir)
                                          throws IOException

抛出:

IOException

writeCorruptedData

protected void writeCorruptedData(RandomAccessFile file)
                           throws IOException

抛出:

IOException

is203LayoutVersion

public static boolean is203LayoutVersion(int layoutVersion)