Package org.apache.hadoop.hdfs

package org.apache.hadoop.hdfs

A distributed implementation of FileSystem. This is loosely modelled after Google's GFS.

The most important difference is that unlike GFS, Hadoop DFS files have strictly one writer at any one time. Bytes are always appended to the end of the writer's stream. There is no notion of "record appends" or "mutations" that are then checked or reordered. Writers simply emit a byte stream. That byte stream is guaranteed to be stored in the order written.

  • Class
    Description
    org.apache.hadoop.hdfs.AddBlockFlag
    AddBlockFlag provides hints for new block allocation and placement.
    org.apache.hadoop.hdfs.BlockMissingException
    This exception is thrown when a read encounters a block that has no locations associated with it.
    org.apache.hadoop.hdfs.BlockReader
    A BlockReader is responsible for reading a single block from a single datanode.
    CannotObtainBlockLengthException
    This exception is thrown when the length of a LocatedBlock instance can not be obtained.
    org.apache.hadoop.hdfs.ClientContext
    ClientContext contains context information for a client.
    org.apache.hadoop.hdfs.ClientGSIContext
    Global State Id context for the client.
    org.apache.hadoop.hdfs.DeadNodeDetector
    Detect the dead nodes in advance, and share this information among all the DFSInputStreams in the same client.
    org.apache.hadoop.hdfs.DeprecatedUTF8
    A simple wrapper around UTF8.
    org.apache.hadoop.hdfs.DFSClient
    DFSClient can connect to a Hadoop Filesystem and perform basic file tasks.
    org.apache.hadoop.hdfs.DFSClient.DFSDataInputStream
    Deprecated.
    use HdfsDataInputStream instead.
    org.apache.hadoop.hdfs.DFSClient.Renewer
     
    org.apache.hadoop.hdfs.DFSClientFaultInjector
    Used for injecting faults in DFSClient and DFSOutputStream tests.
    org.apache.hadoop.hdfs.DFSConfigKeys
    This class contains constants for configuration keys and default values used in hdfs.
    org.apache.hadoop.hdfs.DFSHedgedReadMetrics
    The client-side metrics for hedged read feature.
    DFSInotifyEventInputStream
    Stream for reading inotify events.
    org.apache.hadoop.hdfs.DFSInputStream
    DFSInputStream provides bytes from a named file.
    org.apache.hadoop.hdfs.DFSOpsCountStatistics
    This storage statistics tracks how many times each DFS operation was issued.
    DFSOpsCountStatistics.OpType
    This is for counting distributed file system operations.
    org.apache.hadoop.hdfs.DFSOutputStream
    DFSOutputStream creates files from a stream of bytes.
    org.apache.hadoop.hdfs.DFSPacket
    DFSPacket is used by DataStreamer and DFSOutputStream.
    org.apache.hadoop.hdfs.DFSStripedInputStream
    DFSStripedInputStream reads from striped block groups.
    org.apache.hadoop.hdfs.DFSStripedOutputStream
    This class supports writing files in striped layout and erasure coded format.
    org.apache.hadoop.hdfs.DFSUtil
     
    org.apache.hadoop.hdfs.DFSUtil.ConfiguredNNAddress
    Represent one of the NameNodes configured in the cluster.
    org.apache.hadoop.hdfs.DFSUtil.ServiceComparator
    Comparator for sorting DataNodeInfo[] based on decommissioned and entering_maintenance states.
    org.apache.hadoop.hdfs.DFSUtil.StaleAndSlowComparator
    Comparator for sorting DataNodeInfo[] based on slow, stale, entering_maintenance, decommissioning and decommissioned states.
    org.apache.hadoop.hdfs.DFSUtilClient
     
    org.apache.hadoop.hdfs.DFSUtilClient.CorruptedBlocks
    A utility class as a container to put corrupted blocks, shared by client and datanode.
    org.apache.hadoop.hdfs.DFSUtilClient.SnapshotDiffReportFunction
     
    org.apache.hadoop.hdfs.DFSUtilClient.SnapshotDiffReportListingFunction
     
    org.apache.hadoop.hdfs.DistributedFileSystem
    Implementation of the abstract FileSystem for the DFS system.
    org.apache.hadoop.hdfs.DistributedFileSystem.HdfsDataOutputStreamBuilder
    HdfsDataOutputStreamBuilder provides the HDFS-specific capabilities to write file on HDFS.
    org.apache.hadoop.hdfs.ExtendedBlockId
    An immutable key which identifies a block.
    org.apache.hadoop.hdfs.HAUtil
     
    org.apache.hadoop.hdfs.HAUtilClient
     
    org.apache.hadoop.hdfs.HdfsConfiguration
    Adds deprecated keys into the configuration.
    org.apache.hadoop.hdfs.HdfsDtFetcher
    DtFetcher is an interface which permits the abstraction and separation of delegation token fetch implementaions across different packages and compilation units.
    org.apache.hadoop.hdfs.HdfsKMSUtil
    Utility class for key provider related methods in hdfs client package.
    org.apache.hadoop.hdfs.HDFSPolicyProvider
    PolicyProvider for HDFS protocols.
    org.apache.hadoop.hdfs.KeyProviderCache
     
    org.apache.hadoop.hdfs.LocatedBlocksRefresher
    Periodically refresh the underlying cached LocatedBlocks for eligible registered DFSInputStreams.
    org.apache.hadoop.hdfs.NameNodeProxies
    Create proxy objects to communicate with a remote NN.
    org.apache.hadoop.hdfs.NameNodeProxiesClient
    Create proxy objects with ClientProtocol and HAServiceProtocol to communicate with a remote NN.
    org.apache.hadoop.hdfs.NameNodeProxiesClient.ProxyAndInfo<PROXYTYPE>
    Wrapper for a client proxy as well as its associated service ID.
    org.apache.hadoop.hdfs.PeerCache
    A cache of input stream sockets to Data Node.
    org.apache.hadoop.hdfs.ReadStatistics
    A utility class that maintains statistics for reading.
    org.apache.hadoop.hdfs.RemotePeerFactory
     
    ReplicaAccessor
    The public API for ReplicaAccessor objects.
    ReplicaAccessorBuilder
    The public API for creating a new ReplicaAccessor.
    org.apache.hadoop.hdfs.StripedDataStreamer
    This class extends DataStreamer to support writing striped blocks to datanodes.
    org.apache.hadoop.hdfs.SWebHdfsDtFetcher
    DtFetcher for SWebHdfsFileSystem using the base class HdfsDtFetcher impl.
    UnknownCipherSuiteException
    Thrown when an unknown cipher suite is encountered.
    UnknownCryptoProtocolVersionException
     
    org.apache.hadoop.hdfs.ViewDistributedFileSystem
    The ViewDistributedFileSystem is an extended class to DistributedFileSystem with additional mounting functionality.
    org.apache.hadoop.hdfs.WebHdfsDtFetcher
    DtFetcher for WebHdfsFileSystem using the base class HdfsDtFetcher impl.
    org.apache.hadoop.hdfs.XAttrHelper