org.apache.hadoop.hdfs.server.namenode
Class BackupStorage

java.lang.Object
  extended by org.apache.hadoop.hdfs.server.common.StorageInfo
      extended by org.apache.hadoop.hdfs.server.common.Storage
          extended by org.apache.hadoop.hdfs.server.namenode.FSImage
              extended by org.apache.hadoop.hdfs.server.namenode.BackupStorage
All Implemented Interfaces:
org.apache.hadoop.io.Writable

@InterfaceAudience.Private
public class BackupStorage
extends FSImage


Nested Class Summary
 
Nested classes/interfaces inherited from class org.apache.hadoop.hdfs.server.common.Storage
Storage.StorageDirectory, Storage.StorageDirType, Storage.StorageState
 
Field Summary
 
Fields inherited from class org.apache.hadoop.hdfs.server.namenode.FSImage
checkpointTime, ckptState, editLog, imageDigest, namesystem, newImageDigest, removedStorageDirs
 
Fields inherited from class org.apache.hadoop.hdfs.server.common.Storage
LAST_PRE_UPGRADE_LAYOUT_VERSION, LAST_UPGRADABLE_HADOOP_VERSION, LAST_UPGRADABLE_LAYOUT_VERSION, LAYOUT_VERSIONS_203, LOG, PRE_GENERATIONSTAMP_LAYOUT_VERSION, STORAGE_DIR_CURRENT, STORAGE_FILE_VERSION, storageDirs
 
Fields inherited from class org.apache.hadoop.hdfs.server.common.StorageInfo
cTime, layoutVersion, namespaceID
 
Method Summary
 boolean isPreUpgradableLayout(Storage.StorageDirectory sd)
          Return true if the layout of the given storage directory is from a version of Hadoop prior to the introduction of the "current" and "previous" directories which allow upgrade and rollback.
 
Methods inherited from class org.apache.hadoop.hdfs.server.namenode.FSImage
format, getEditLog, getFields, getFsEditName, getFSNamesystem, getRestoreFailedStorage, moveCurrent, moveLastCheckpoint, saveCurrent, setFields, setImageDigest, setRestoreFailedStorage
 
Methods inherited from class org.apache.hadoop.hdfs.server.common.Storage
addStorageDir, checkVersionUpgradable, deleteDir, dirIterator, dirIterator, getBuildVersion, getNumStorageDirs, getRegistrationID, getStorageDir, is203LayoutVersion, isLockSupported, listStorageDirectories, rename, unlockAll, writeAll
 
Methods inherited from class org.apache.hadoop.hdfs.server.common.StorageInfo
getCTime, getLayoutVersion, getNamespaceID, readFields, setStorageInfo, write
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

isPreUpgradableLayout

public boolean isPreUpgradableLayout(Storage.StorageDirectory sd)
                              throws IOException
Description copied from class: Storage
Return true if the layout of the given storage directory is from a version of Hadoop prior to the introduction of the "current" and "previous" directories which allow upgrade and rollback.

Overrides:
isPreUpgradableLayout in class FSImage
Throws:
IOException


Copyright © 2009 The Apache Software Foundation