FSNamesystem (Hadoop 1.2.2-SNAPSHOT API)

java.lang.Object
- org.apache.hadoop.hdfs.server.namenode.FSNamesystem

所有已实现的接口:

FSConstants, FSClusterStats, FSNamesystemMBean, NameNodeMXBean, MetricsSource
```
public class FSNamesystem
extends Object
implements FSConstants, FSNamesystemMBean, FSClusterStats, NameNodeMXBean, MetricsSource
```
FSNamesystem does the actual bookkeeping work for the DataNode. It tracks several important tables. 1) valid fsname --> blocklist (kept on disk, logged) 2) Set of all valid blocks (inverted #1) 3) block --> machinelist (kept in memory, rebuilt dynamically from reports) 4) machine --> blocklist (inverted #2) 5) LRU cache of updated-heartbeat machines

嵌套类概要
- 从接口继承的嵌套类/接口 org.apache.hadoop.hdfs.protocol.FSConstants
  FSConstants.DatanodeReportType, FSConstants.SafeModeAction, FSConstants.UpgradeAction

字段概要

字段
限定符和类型	字段和说明
`static String`	`AUDIT_FORMAT`
`static org.apache.commons.logging.Log`	`auditLog`
`CorruptReplicasMap`	`corruptReplicas`
`static int`	`DEFAULT_INITIAL_MAP_CAPACITY`
`static float`	`DEFAULT_MAP_LOAD_FACTOR`
`org.apache.hadoop.hdfs.server.namenode.FSDirectory`	`dir`
`static FSNamesystem`	`fsNamesystemObject`
`LeaseManager`	`leaseManager`
`Daemon`	`lmthread`
`static org.apache.commons.logging.Log`	`LOG`
`Daemon`	`replthread`

从接口继承的字段 org.apache.hadoop.hdfs.protocol.FSConstants
BLOCKREPORT_INITIAL_DELAY, BLOCKREPORT_INTERVAL, BUFFER_SIZE, DEFAULT_BLOCK_SIZE, DEFAULT_DATA_SOCKET_SIZE, HEARTBEAT_INTERVAL, LAYOUT_VERSION, LEASE_HARDLIMIT_PERIOD, LEASE_RECOVER_PERIOD, LEASE_SOFTLIMIT_PERIOD, MAX_PATH_DEPTH, MAX_PATH_LENGTH, MIN_BLOCKS_FOR_WRITE, QUOTA_DONT_SET, QUOTA_RESET, SIZE_OF_INTEGER, SMALL_BUFFER_SIZE

方法概要

方法
限定符和类型	方法和说明
`boolean`	`abandonBlock(Block b, String src, String holder)` The client would like to let go of the given block
`void`	`blockReceived(DatanodeID nodeID, Block block, String delHint)` The given node is reporting that it received a certain block.
`void`	`cancelDelegationToken(Token<DelegationTokenIdentifier> token)`
`DatanodeInfo`	`chooseDatanode(String srcPath, String address, long blocksize)` Choose a datanode near to the given address.
`void`	`close()` Close down this file system manager.
`void`	`commitBlockSynchronization(Block lastblock, long newgenerationstamp, long newlength, boolean closeFile, boolean deleteblock, DatanodeID[] newtargets)`
`org.apache.hadoop.hdfs.server.namenode.FSNamesystem.CompleteFileStatus`	`completeFile(String src, String holder)`
`int`	`computeDatanodeWork()` Compute block replication and block invalidation work that can be scheduled on data-nodes.
`DatanodeInfo[]`	`datanodeReport(FSConstants.DatanodeReportType type)`
`boolean`	`delete(String src, boolean recursive)` Remove the indicated filename from namespace.
`void`	`DFSNodesStatus(ArrayList<DatanodeDescriptor> live, ArrayList<DatanodeDescriptor> dead)`
`LocatedBlock`	`getAdditionalBlock(String src, String clientName)` Stub for old callers pre-HDFS-630
`LocatedBlock`	`getAdditionalBlock(String src, String clientName, HashMap<Node,Node> excludedNodes)` The client would like to obtain an additional block for the indicated filename (which is being written-to).
`int`	`getBlockCapacity()`
`LocatedBlocks`	`getBlockLocations(String src, long offset, long length)` Get block locations within the specified range.
`LocatedBlocks`	`getBlockLocations(String src, long offset, long length, boolean doAccessTime, boolean needBlockToken, boolean checkSafeMode)` Get block locations within the specified range.
`long`	`getBlocksTotal()` Get the total number of blocks in the system.
`long`	`getCapacityRemaining()` Total non-used raw bytes.
`float`	`getCapacityRemainingPercent()` Total remaining space by data nodes as percentage of total capacity
`long`	`getCapacityTotal()` Total raw bytes including non-dfs used space.
`long`	`getCapacityUsed()` Total used space by data nodes
`long`	`getCapacityUsedNonDFS()` Total used space by data nodes for non DFS purposes such as storing temporary files on the local file system
`float`	`getCapacityUsedPercent()` Total used space by data nodes as percentage of total capacity
`long`	`getCorruptReplicaBlocks()` Returns number of blocks with corrupt replicas
`DatanodeDescriptor`	`getDatanode(DatanodeID nodeID)` Get data node by storage ID.
`DatanodeInfo`	`getDataNodeInfo(String name)`
`ArrayList<DatanodeDescriptor>`	`getDatanodeListForReport(FSConstants.DatanodeReportType type)`
`String`	`getDeadNodes()` Returned information is a JSON representation of map with host name as the key and value is a map of dead node attribute keys to its values
`ArrayList<DatanodeDescriptor>`	`getDecommissioningNodes()`
`String`	`getDecomNodes()` Returned information is a JSON representation of map with host name as the key and value is a map of decomisioning node attribute keys to its values
`Token<DelegationTokenIdentifier>`	`getDelegationToken(Text renewer)`
`DelegationTokenSecretManager`	`getDelegationTokenSecretManager()` Returns the DelegationTokenSecretManager instance in the namesystem.
`InetSocketAddress`	`getDFSNameNodeAddress()` 已过时。 use `NameNode.getNameNodeAddress()` instead.
`long`	`getExcessBlocks()`
`long`	`getFilesTotal()` Total number of files and directories
`long`	`getFree()` Gets total non-used raw bytes.
`static FSNamesystem`	`getFSNamesystem()` Return the FSNamesystem object
`String`	`getFSState()` The state of the file system: Safemode or Operational
`long`	`getGenerationStamp()` Gets the generation stamp for this filesystem
`String`	`getHostName()`
`DirectoryListing`	`getListing(String src, byte[] startAfter)` Get a partial listing of the indicated directory
`String`	`getLiveNodes()` Returned information is a JSON representation of map with host name as the key and value is a map of live node attribute keys to its values
`void`	`getMetrics(MetricsBuilder builder, boolean all)` Get metrics from the source
`long`	`getMissingBlocksCount()`
`String`	`getNameDirStatuses()` Get status information about the directories storing image and edits logs of the NN.
`static Collection<File>`	`getNamespaceDirs(Configuration conf)`
`static Collection<File>`	`getNamespaceEditsDirs(Configuration conf)`
`long`	`getNonDfsUsedSpace()` Gets total used space by data nodes for non DFS purposes such as storing temporary files on the local file system
`int`	`getNumStaleNodes()`
`long`	`getPendingDeletionBlocks()`
`long`	`getPendingReplicationBlocks()` Blocks pending to be replicated
`float`	`getPercentRemaining()` Gets the total remaining space by data nodes as percentage of total capacity
`float`	`getPercentUsed()` Gets the total used space by data nodes as percentage of total capacity
`DatanodeDescriptor`	`getRandomDatanode()`
`String`	`getRegistrationID()` Get registrationID for datanodes based on the namespaceID.
`String`	`getSafemode()` Gets the safemode status
`String`	`getSafeModeTip()`
`long`	`getScheduledReplicationBlocks()` Blocks scheduled for replication
`Date`	`getStartTime()`
`int`	`getThreads()` Gets the number of threads.
`long`	`getTotal()` Gets total raw bytes including non-dfs used space.
`long`	`getTotalBlocks()` Gets the total numbers of blocks on the cluster.
`long`	`getTotalFiles()` Gets the total number of files on the cluster
`int`	`getTotalLoad()` Total number of connections.
`long`	`getUnderReplicatedBlocks()` Blocks under replicated
`protected PermissionStatus`	`getUpgradePermission()` Return the default path permission when upgrading from releases with no permissions (<=0.15) to releases with permissions (>=0.16)
`long`	`getUsed()` Gets the used space by data nodes.
`String`	`getVersion()` Gets the version of Hadoop.
`boolean`	`isUpgradeFinalized()` Checks if upgrade is finalized.
`void`	`logUpdateMasterKey(DelegationKey key)` Log the updateMasterKey operation to edit logs
`void`	`markBlockAsCorrupt(Block blk, DatanodeInfo dn)` Mark the block belonging to datanode as corrupt
`boolean`	`mkdirs(String src, PermissionStatus permissions)` Create all the necessary directories
`int`	`numDeadDataNodes()` Number of dead data nodes
`int`	`numLiveDataNodes()` Number of live data nodes
`void`	`processBlocksBeingWrittenReport(DatanodeID nodeID, BlockListAsLongs blocksBeingWritten)` It will update the targets for INodeFileUnderConstruction
`void`	`processReport(DatanodeID nodeID, BlockListAsLongs newReport)` The given node is reporting all its blocks.
`String`	`randomDataNode()` 已过时。
`void`	`refreshNodes(Configuration conf)` Rereads the config to get hosts and exclude list file names.
`void`	`registerDatanode(DatanodeRegistration nodeReg)` Register Datanode.
`void`	`removeDatanode(DatanodeID nodeID)` remove a datanode descriptor
`boolean`	`renameTo(String src, String dst)` Change the indicated filename.
`long`	`renewDelegationToken(Token<DelegationTokenIdentifier> token)`
`void`	`restartReplicationWork()`
`void`	`setBalancerBandwidth(long bandwidth)` Tell all datanodes to use a new, non-persistent bandwidth value for dfs.balance.bandwidthPerSec.
`void`	`setGenerationStamp(long stamp)` Sets the generation stamp for this filesystem
`void`	`setNodeReplicationLimit(int limit)`
`void`	`setOwner(String src, String username, String group)` Set owner for an existing file.
`void`	`setPermission(String src, FsPermission permission)` Set permissions for an existing file.
`boolean`	`setReplication(String src, short replication)` Set replication for an existing file.
`void`	`setTimes(String src, long mtime, long atime)` stores the modification and access time for this inode.
`boolean`	`shouldAvoidStaleDataNodesForWrite()` Indicate whether or not the cluster is now avoiding to use stale DataNodes for writing.
`void`	`shutdown()` shutdown FSNamesystem
`void`	`stallReplicationWork()`
`void`	`stopDecommission(DatanodeDescriptor node)` Stop decommissioning the specified datanodes.
`String`	`toString()`

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- 字段详细资料
  - LOG
```
public static final org.apache.commons.logging.Log LOG
```
  - AUDIT_FORMAT
```
public static final String AUDIT_FORMAT
```
    另请参阅:
    常量字段值
  - auditLog
```
public static final org.apache.commons.logging.Log auditLog
```
  - DEFAULT_INITIAL_MAP_CAPACITY
```
public static final int DEFAULT_INITIAL_MAP_CAPACITY
```
    另请参阅:
    常量字段值
  - DEFAULT_MAP_LOAD_FACTOR
```
public static final float DEFAULT_MAP_LOAD_FACTOR
```
    另请参阅:
    常量字段值
  - dir
```
public org.apache.hadoop.hdfs.server.namenode.FSDirectory dir
```
  - corruptReplicas
```
public CorruptReplicasMap corruptReplicas
```
  - leaseManager
```
public LeaseManager leaseManager
```
  - lmthread
```
public Daemon lmthread
```
  - replthread
```
public Daemon replthread
```
  - fsNamesystemObject
```
public static FSNamesystem fsNamesystemObject
```
- 方法详细资料
  - getNamespaceDirs
```
public static Collection<File> getNamespaceDirs(Configuration conf)
```
  - getNamespaceEditsDirs
```
public static Collection<File> getNamespaceEditsDirs(Configuration conf)
```
  - getUpgradePermission
```
protected PermissionStatus getUpgradePermission()
```
    Return the default path permission when upgrading from releases with no permissions (<=0.15) to releases with permissions (>=0.16)
  - getFSNamesystem
```
public static FSNamesystem getFSNamesystem()
```
    Return the FSNamesystem object
  - close
```
public void close()
```
    Close down this file system manager. Causes heartbeat and lease daemons to stop; waits briefly for them to finish, but a short timeout returns control back to caller.
  - setBalancerBandwidth
```
public void setBalancerBandwidth(long bandwidth)
                          throws IOException
```
    Tell all datanodes to use a new, non-persistent bandwidth value for dfs.balance.bandwidthPerSec. A system administrator can tune the balancer bandwidth parameter (dfs.balance.bandwidthPerSec) dynamically by calling "dfsadmin -setBalanacerBandwidth newbandwidth", at which point the following 'bandwidth' variable gets updated with the new value for each node. Once the heartbeat command is issued to update the value on the specified datanode, this value will be set back to 0.
    
    参数:
    bandwidth - Blanacer bandwidth in bytes per second for all datanodes.
    
    抛出:
    
    IOException
  - setPermission
```
public void setPermission(String src,
                 FsPermission permission)
                   throws IOException
```
    Set permissions for an existing file.
    
    抛出:
    
    IOException
  - setOwner
```
public void setOwner(String src,
            String username,
            String group)
              throws IOException
```
    Set owner for an existing file.
    
    抛出:
    
    IOException
  - getBlockLocations
```
public LocatedBlocks getBlockLocations(String src,
                              long offset,
                              long length)
                                throws IOException
```
    Get block locations within the specified range.
    
    抛出:
    
    IOException
    另请参阅:
    ClientProtocol.getBlockLocations(String, long, long)
  - getBlockLocations
```
public LocatedBlocks getBlockLocations(String src,
                              long offset,
                              long length,
                              boolean doAccessTime,
                              boolean needBlockToken,
                              boolean checkSafeMode)
                                throws IOException
```
    Get block locations within the specified range.
    
    抛出:
    
    IOException
    另请参阅:
    ClientProtocol.getBlockLocations(String, long, long)
  - setTimes
```
public void setTimes(String src,
            long mtime,
            long atime)
              throws IOException
```
    stores the modification and access time for this inode. The access time is precise upto an hour. The transaction, if needed, is written to the edits log but is not flushed.
    
    抛出:
    
    IOException
  - setReplication
```
public boolean setReplication(String src,
                     short replication)
                       throws IOException
```
    Set replication for an existing file. The NameNode sets new replication and schedules either replication of under-replicated data blocks or removal of the eccessive block copies if the blocks are over-replicated.
    
    参数:
    src - file name
    replication - new replication
    
    返回:
    true if successful; false if file does not exist or is a directory
    
    抛出:
    
    IOException
    另请参阅:
    ClientProtocol.setReplication(String, short)
  - getAdditionalBlock
```
public LocatedBlock getAdditionalBlock(String src,
                              String clientName)
                                throws IOException
```
    Stub for old callers pre-HDFS-630
    
    抛出:
    
    IOException
  - getAdditionalBlock
```
public LocatedBlock getAdditionalBlock(String src,
                              String clientName,
                              HashMap<Node,Node> excludedNodes)
                                throws IOException
```
    The client would like to obtain an additional block for the indicated filename (which is being written-to). Return an array that consists of the block, plus a set of machines. The first on this list should be where the client writes data. Subsequent items in the list must be provided in the connection to the first datanode. Make sure the previous blocks have been reported by datanodes and are replicated. Will return an empty 2-elt array if we want the client to "try again later".
    
    抛出:
    
    IOException
  - abandonBlock
```
public boolean abandonBlock(Block b,
                   String src,
                   String holder)
                     throws IOException
```
    The client would like to let go of the given block
    
    抛出:
    
    IOException
  - completeFile
```
public org.apache.hadoop.hdfs.server.namenode.FSNamesystem.CompleteFileStatus completeFile(String src,
                                                                                  String holder)
                                                                                    throws IOException
```
    抛出:
    
    IOException
  - markBlockAsCorrupt
```
public void markBlockAsCorrupt(Block blk,
                      DatanodeInfo dn)
                        throws IOException
```
    Mark the block belonging to datanode as corrupt
    
    参数:
    blk - Block to be marked as corrupt
    dn - Datanode which holds the corrupt replica
    
    抛出:
    
    IOException
  - renameTo
```
public boolean renameTo(String src,
               String dst)
                 throws IOException
```
    Change the indicated filename.
    
    抛出:
    
    IOException
  - delete
```
public boolean delete(String src,
             boolean recursive)
               throws IOException
```
    Remove the indicated filename from namespace. If the filename is a directory (non empty) and recursive is set to false then throw exception.
    
    抛出:
    
    IOException
  - mkdirs
```
public boolean mkdirs(String src,
             PermissionStatus permissions)
               throws IOException
```
    Create all the necessary directories
    
    抛出:
    
    IOException
  - commitBlockSynchronization
```
public void commitBlockSynchronization(Block lastblock,
                              long newgenerationstamp,
                              long newlength,
                              boolean closeFile,
                              boolean deleteblock,
                              DatanodeID[] newtargets)
                                throws IOException
```
    抛出:
    
    IOException
  - getListing
```
public DirectoryListing getListing(String src,
                          byte[] startAfter)
                            throws IOException
```
    Get a partial listing of the indicated directory
    
    参数:
    src - the directory name
    startAfter - the name to start after
    
    返回:
    a partial listing starting after startAfter
    
    抛出:
    
    IOException
  - registerDatanode
```
public void registerDatanode(DatanodeRegistration nodeReg)
                      throws IOException
```
    Register Datanode.
    The purpose of registration is to identify whether the new datanode serves a new data storage, and will report new data block copies, which the namenode was not aware of; or the datanode is a replacement node for the data storage that was previously served by a different or the same (in terms of host:port) datanode. The data storages are distinguished by their storageIDs. When a new data storage is reported the namenode issues a new unique storageID.
    Finally, the namenode returns its namespaceID as the registrationID for the datanodes. namespaceID is a persistent attribute of the name space. The registrationID is checked every time the datanode is communicating with the namenode. Datanodes with inappropriate registrationID are rejected. If the namenode stops, and then restarts it can restore its namespaceID and will continue serving the datanodes that has previously registered with the namenode without restarting the whole cluster.
    
    抛出:
    
    IOException
    另请参阅:
    DataNode.register()
  - getRegistrationID
```
public String getRegistrationID()
```
    Get registrationID for datanodes based on the namespaceID.
    
    返回:
    registration ID
    另请参阅:
    registerDatanode(DatanodeRegistration), FSImage.newNamespaceID()
  - computeDatanodeWork
```
public int computeDatanodeWork()
                        throws IOException
```
    Compute block replication and block invalidation work that can be scheduled on data-nodes. The datanode will be informed of this work at the next heartbeat.
    
    返回:
    number of blocks scheduled for replication or removal.
    
    抛出:
    
    IOException
  - chooseDatanode
```
public DatanodeInfo chooseDatanode(String srcPath,
                          String address,
                          long blocksize)
```
    Choose a datanode near to the given address.
  - setNodeReplicationLimit
```
public void setNodeReplicationLimit(int limit)
```
  - removeDatanode
```
public void removeDatanode(DatanodeID nodeID)
                    throws IOException
```
    remove a datanode descriptor
    
    参数:
    nodeID - datanode ID
    
    抛出:
    
    IOException
  - processBlocksBeingWrittenReport
```
public void processBlocksBeingWrittenReport(DatanodeID nodeID,
                                   BlockListAsLongs blocksBeingWritten)
                                     throws IOException
```
    It will update the targets for INodeFileUnderConstruction
    
    参数:
    nodeID - - DataNode ID
    blocksBeingWritten - - list of blocks which are still inprogress.
    
    抛出:
    
    IOException
  - processReport
```
public void processReport(DatanodeID nodeID,
                 BlockListAsLongs newReport)
                   throws IOException
```
    The given node is reporting all its blocks. Use this info to update the (machine-->blocklist) and (block-->machinelist) tables.
    
    抛出:
    
    IOException
  - blockReceived
```
public void blockReceived(DatanodeID nodeID,
                 Block block,
                 String delHint)
                   throws IOException
```
    The given node is reporting that it received a certain block.
    
    抛出:
    
    IOException
  - getMissingBlocksCount
```
public long getMissingBlocksCount()
```
  - getCapacityTotal
```
public long getCapacityTotal()
```
    Total raw bytes including non-dfs used space.
    
    指定者:
    
    getCapacityTotal 在接口中 FSNamesystemMBean
    
    返回:
    - total capacity in bytes
  - getCapacityUsed
```
public long getCapacityUsed()
```
    Total used space by data nodes
    
    指定者:
    
    getCapacityUsed 在接口中 FSNamesystemMBean
    
    返回:
    - used capacity in bytes
  - getCapacityUsedPercent
```
public float getCapacityUsedPercent()
```
    Total used space by data nodes as percentage of total capacity
  - getCapacityUsedNonDFS
```
public long getCapacityUsedNonDFS()
```
    Total used space by data nodes for non DFS purposes such as storing temporary files on the local file system
  - getCapacityRemaining
```
public long getCapacityRemaining()
```
    Total non-used raw bytes.
    
    指定者:
    
    getCapacityRemaining 在接口中 FSNamesystemMBean
    
    返回:
    - free capacity in bytes
  - getCapacityRemainingPercent
```
public float getCapacityRemainingPercent()
```
    Total remaining space by data nodes as percentage of total capacity
  - getTotalLoad
```
public int getTotalLoad()
```
    Total number of connections.
    
    指定者:
    
    getTotalLoad 在接口中 FSClusterStats
    
    指定者:
    
    getTotalLoad 在接口中 FSNamesystemMBean
    
    返回:
    - total load of FSNamesystem
  - getDatanodeListForReport
```
public ArrayList<DatanodeDescriptor> getDatanodeListForReport(FSConstants.DatanodeReportType type)
```
  - datanodeReport
```
public DatanodeInfo[] datanodeReport(FSConstants.DatanodeReportType type)
                              throws AccessControlException
```
    抛出:
    
    AccessControlException
  - DFSNodesStatus
```
public void DFSNodesStatus(ArrayList<DatanodeDescriptor> live,
                  ArrayList<DatanodeDescriptor> dead)
```
  - stopDecommission
```
public void stopDecommission(DatanodeDescriptor node)
                      throws IOException
```
    Stop decommissioning the specified datanodes.
    
    抛出:
    
    IOException
  - getDataNodeInfo
```
public DatanodeInfo getDataNodeInfo(String name)
```
  - getDFSNameNodeAddress
```
@Deprecated
public InetSocketAddress getDFSNameNodeAddress()
```
    已过时。 use NameNode.getNameNodeAddress() instead.
  - getStartTime
```
public Date getStartTime()
```
  - stallReplicationWork
```
public void stallReplicationWork()
```
  - restartReplicationWork
```
public void restartReplicationWork()
```
  - refreshNodes
```
public void refreshNodes(Configuration conf)
                  throws IOException
```
    Rereads the config to get hosts and exclude list file names. Rereads the files to update the hosts and exclude lists. It checks if any of the hosts have changed states: 1. Added to hosts --> no further work needed here. 2. Removed from hosts --> mark AdminState as decommissioned. 3. Added to exclude --> start decommission. 4. Removed from exclude --> stop decommission.
    
    抛出:
    
    IOException
  - getDatanode
```
public DatanodeDescriptor getDatanode(DatanodeID nodeID)
                               throws IOException
```
    Get data node by storage ID.
    
    参数:
    nodeID -
    
    返回:
    DatanodeDescriptor or null if the node is not found.
    
    抛出:
    
    IOException
  - randomDataNode
```
@Deprecated
public String randomDataNode()
```
    已过时。
  - getRandomDatanode
```
public DatanodeDescriptor getRandomDatanode()
```
  - getBlocksTotal
```
public long getBlocksTotal()
```
    Get the total number of blocks in the system.
    
    指定者:
    
    getBlocksTotal 在接口中 FSNamesystemMBean
    
    返回:
    - number of allocated blocks
  - getSafeModeTip
```
public String getSafeModeTip()
```
  - getFilesTotal
```
public long getFilesTotal()
```
    从接口复制的说明: FSNamesystemMBean
    
    Total number of files and directories
    
    指定者:
    
    getFilesTotal 在接口中 FSNamesystemMBean
    
    返回:
    - num of files and directories
  - getPendingReplicationBlocks
```
public long getPendingReplicationBlocks()
```
    从接口复制的说明: FSNamesystemMBean
    
    Blocks pending to be replicated
    
    指定者:
    
    getPendingReplicationBlocks 在接口中 FSNamesystemMBean
    
    返回:
    - num of blocks to be replicated
  - getUnderReplicatedBlocks
```
public long getUnderReplicatedBlocks()
```
    从接口复制的说明: FSNamesystemMBean
    
    Blocks under replicated
    
    指定者:
    
    getUnderReplicatedBlocks 在接口中 FSNamesystemMBean
    
    返回:
    - num of blocks under replicated
  - getCorruptReplicaBlocks
```
public long getCorruptReplicaBlocks()
```
    Returns number of blocks with corrupt replicas
  - getScheduledReplicationBlocks
```
public long getScheduledReplicationBlocks()
```
    从接口复制的说明: FSNamesystemMBean
    
    Blocks scheduled for replication
    
    指定者:
    
    getScheduledReplicationBlocks 在接口中 FSNamesystemMBean
    
    返回:
    - num of blocks scheduled for replication
  - getPendingDeletionBlocks
```
public long getPendingDeletionBlocks()
```
  - getExcessBlocks
```
public long getExcessBlocks()
```
  - getBlockCapacity
```
public int getBlockCapacity()
```
  - getFSState
```
public String getFSState()
```
    从接口复制的说明: FSNamesystemMBean
    
    The state of the file system: Safemode or Operational
    
    指定者:
    
    getFSState 在接口中 FSNamesystemMBean
    
    返回:
    the state
  - shutdown
```
public void shutdown()
```
    shutdown FSNamesystem
  - numLiveDataNodes
```
public int numLiveDataNodes()
```
    Number of live data nodes
    
    指定者:
    
    numLiveDataNodes 在接口中 FSNamesystemMBean
    
    返回:
    Number of live data nodes
  - numDeadDataNodes
```
public int numDeadDataNodes()
```
    Number of dead data nodes
    
    指定者:
    
    numDeadDataNodes 在接口中 FSNamesystemMBean
    
    返回:
    Number of dead data nodes
  - setGenerationStamp
```
public void setGenerationStamp(long stamp)
```
    Sets the generation stamp for this filesystem
  - getGenerationStamp
```
public long getGenerationStamp()
```
    Gets the generation stamp for this filesystem
  - getDecommissioningNodes
```
public ArrayList<DatanodeDescriptor> getDecommissioningNodes()
```
  - getDelegationTokenSecretManager
```
public DelegationTokenSecretManager getDelegationTokenSecretManager()
```
    Returns the DelegationTokenSecretManager instance in the namesystem.
    
    返回:
    delegation token secret manager object
  - getDelegationToken
```
public Token<DelegationTokenIdentifier> getDelegationToken(Text renewer)
                                                    throws IOException
```
    参数:
    renewer -
    
    返回:
    Token
    
    抛出:
    
    IOException
  - renewDelegationToken
```
public long renewDelegationToken(Token<DelegationTokenIdentifier> token)
                          throws SecretManager.InvalidToken,
                                 IOException
```
    参数:
    token -
    
    返回:
    New expiryTime of the token
    
    抛出:
    
    SecretManager.InvalidToken
    
    IOException
  - cancelDelegationToken
```
public void cancelDelegationToken(Token<DelegationTokenIdentifier> token)
                           throws IOException
```
    参数:
    token -
    
    抛出:
    
    IOException
  - logUpdateMasterKey
```
public void logUpdateMasterKey(DelegationKey key)
                        throws IOException
```
    Log the updateMasterKey operation to edit logs
    
    参数:
    key - new delegation key.
    
    抛出:
    
    IOException
  - getHostName
```
public String getHostName()
```
    指定者:
    
    getHostName 在接口中 NameNodeMXBean
    
    返回:
    the host name
  - getVersion
```
public String getVersion()
```
    从接口复制的说明: NameNodeMXBean
    
    Gets the version of Hadoop.
    
    指定者:
    
    getVersion 在接口中 NameNodeMXBean
    
    返回:
    the version
  - getUsed
```
public long getUsed()
```
    从接口复制的说明: NameNodeMXBean
    
    Gets the used space by data nodes.
    
    指定者:
    
    getUsed 在接口中 NameNodeMXBean
    
    返回:
    the used space by data nodes
  - getFree
```
public long getFree()
```
    从接口复制的说明: NameNodeMXBean
    
    Gets total non-used raw bytes.
    
    指定者:
    
    getFree 在接口中 NameNodeMXBean
    
    返回:
    total non-used raw bytes
  - getTotal
```
public long getTotal()
```
    从接口复制的说明: NameNodeMXBean
    
    Gets total raw bytes including non-dfs used space.
    
    指定者:
    
    getTotal 在接口中 NameNodeMXBean
    
    返回:
    the total raw bytes including non-dfs used space
  - getSafemode
```
public String getSafemode()
```
    从接口复制的说明: NameNodeMXBean
    
    Gets the safemode status
    
    指定者:
    
    getSafemode 在接口中 NameNodeMXBean
    
    返回:
    the safemode status
  - isUpgradeFinalized
```
public boolean isUpgradeFinalized()
```
    从接口复制的说明: NameNodeMXBean
    
    Checks if upgrade is finalized.
    
    指定者:
    
    isUpgradeFinalized 在接口中 NameNodeMXBean
    
    返回:
    true, if upgrade is finalized
  - getNonDfsUsedSpace
```
public long getNonDfsUsedSpace()
```
    从接口复制的说明: NameNodeMXBean
    
    Gets total used space by data nodes for non DFS purposes such as storing temporary files on the local file system
    
    指定者:
    
    getNonDfsUsedSpace 在接口中 NameNodeMXBean
    
    返回:
    the non dfs space of the cluster
  - getPercentUsed
```
public float getPercentUsed()
```
    从接口复制的说明: NameNodeMXBean
    
    Gets the total used space by data nodes as percentage of total capacity
    
    指定者:
    
    getPercentUsed 在接口中 NameNodeMXBean
    
    返回:
    the percentage of used space on the cluster.
  - getPercentRemaining
```
public float getPercentRemaining()
```
    从接口复制的说明: NameNodeMXBean
    
    Gets the total remaining space by data nodes as percentage of total capacity
    
    指定者:
    
    getPercentRemaining 在接口中 NameNodeMXBean
    
    返回:
    the percentage of the remaining space on the cluster
  - getTotalBlocks
```
public long getTotalBlocks()
```
    从接口复制的说明: NameNodeMXBean
    
    Gets the total numbers of blocks on the cluster.
    
    指定者:
    
    getTotalBlocks 在接口中 NameNodeMXBean
    
    返回:
    the total number of blocks of the cluster
  - getTotalFiles
```
public long getTotalFiles()
```
    从接口复制的说明: NameNodeMXBean
    
    Gets the total number of files on the cluster
    
    指定者:
    
    getTotalFiles 在接口中 NameNodeMXBean
    
    返回:
    the total number of files on the cluster
  - getThreads
```
public int getThreads()
```
    从接口复制的说明: NameNodeMXBean
    
    Gets the number of threads.
    
    指定者:
    
    getThreads 在接口中 NameNodeMXBean
    
    返回:
    the number of threads
  - getLiveNodes
```
public String getLiveNodes()
```
    Returned information is a JSON representation of map with host name as the key and value is a map of live node attribute keys to its values
    
    指定者:
    
    getLiveNodes 在接口中 NameNodeMXBean
    
    返回:
    the live node information
  - getDeadNodes
```
public String getDeadNodes()
```
    Returned information is a JSON representation of map with host name as the key and value is a map of dead node attribute keys to its values
    
    指定者:
    
    getDeadNodes 在接口中 NameNodeMXBean
    
    返回:
    the dead node information
  - getDecomNodes
```
public String getDecomNodes()
```
    Returned information is a JSON representation of map with host name as the key and value is a map of decomisioning node attribute keys to its values
    
    指定者:
    
    getDecomNodes 在接口中 NameNodeMXBean
    
    返回:
    the decommissioning node information
  - getNameDirStatuses
```
public String getNameDirStatuses()
```
    从接口复制的说明: NameNodeMXBean
    
    Get status information about the directories storing image and edits logs of the NN.
    
    指定者:
    
    getNameDirStatuses 在接口中 NameNodeMXBean
    
    返回:
    the name dir status information, as a JSON string.
  - getMetrics
```
public void getMetrics(MetricsBuilder builder,
              boolean all)
```
    从接口复制的说明: MetricsSource
    
    Get metrics from the source
    
    指定者:
    
    getMetrics 在接口中 MetricsSource
    
    参数:
    builder - to contain the resulting metrics snapshot
    all - if true, return all metrics even if unchanged.
  - toString
```
public String toString()
```
    覆盖:
    
    toString 在类中 Object
  - getNumStaleNodes
```
public int getNumStaleNodes()
```
    返回:
    Return the current number of stale DataNodes (detected by HeartbeatMonitor).
  - shouldAvoidStaleDataNodesForWrite
```
public boolean shouldAvoidStaleDataNodesForWrite()
```
    从接口复制的说明: FSClusterStats
    
    Indicate whether or not the cluster is now avoiding to use stale DataNodes for writing.
    
    指定者:
    
    shouldAvoidStaleDataNodesForWrite 在接口中 FSClusterStats
    
    返回:
    True if the cluster is currently avoiding using stale DataNodes for writing targets, and false otherwise.

类 FSNamesystem

嵌套类概要

从接口继承的嵌套类/接口 org.apache.hadoop.hdfs.protocol.FSConstants

字段概要

从接口继承的字段 org.apache.hadoop.hdfs.protocol.FSConstants

方法概要

从类继承的方法 java.lang.Object

字段详细资料

LOG

AUDIT_FORMAT

auditLog

DEFAULT_INITIAL_MAP_CAPACITY

DEFAULT_MAP_LOAD_FACTOR

dir

corruptReplicas

leaseManager

lmthread

replthread

fsNamesystemObject

方法详细资料

getNamespaceDirs

getNamespaceEditsDirs

getUpgradePermission

getFSNamesystem

close

setBalancerBandwidth

setPermission

setOwner

getBlockLocations

getBlockLocations

setTimes

setReplication

getAdditionalBlock

getAdditionalBlock

abandonBlock

completeFile

markBlockAsCorrupt

renameTo

delete

mkdirs

commitBlockSynchronization

getListing

registerDatanode

getRegistrationID

computeDatanodeWork

chooseDatanode

setNodeReplicationLimit

removeDatanode

processBlocksBeingWrittenReport

processReport

blockReceived

getMissingBlocksCount

getCapacityTotal

getCapacityUsed

getCapacityUsedPercent

getCapacityUsedNonDFS

getCapacityRemaining

getCapacityRemainingPercent

getTotalLoad

getDatanodeListForReport

datanodeReport

DFSNodesStatus

stopDecommission

getDataNodeInfo

getDFSNameNodeAddress

getStartTime

stallReplicationWork

restartReplicationWork

refreshNodes

getDatanode

randomDataNode

getRandomDatanode

getBlocksTotal

getSafeModeTip

getFilesTotal

getPendingReplicationBlocks

getUnderReplicatedBlocks

getCorruptReplicaBlocks

getScheduledReplicationBlocks

getPendingDeletionBlocks