Package org.apache.hadoop.hdfs.server.datanode

Interface Summary

Interface	Description
BPServiceActorAction	Base class for BPServiceActor class Issued by BPOfferSerivce class to tell BPServiceActor to take several actions.
ReplicaInPipelineInterface	This defines the interface of a replica in Pipeline that's being written to
ShortCircuitRegistry.Visitor

Class Summary

Class	Description
ChunkChecksum	holder class that holds checksum bytes and the length in a block at which the checksum bytes end ex: length = 1023 and checksum is 4 bytes which is for 512 bytes, then the checksum applies for the last chunk, or bytes 512 - 1023
ErrorReportAction	A ErrorReportAction is an instruction issued by BPOfferService to BPServiceActor about a particular block encapsulated in errorMessage.
FinalizedReplica	This class describes a replica that has been finalized.
ReplicaBeingWritten	This class represents replicas being written.
ReplicaHandler	This class includes a replica being actively written and the reference to the fs volume where this replica is located.
ReplicaInfo.ReplicaDirInfo
ReplicaInPipeline	This class defines a replica in a pipeline, which includes a persistent replica being written to by a dfs client or a temporary replica being replicated by a source datanode or being copied for the balancing purpose.
ReplicaUnderRecovery	This class represents replicas that are under block recovery It has a recovery id that is equal to the generation stamp that the replica will be bumped to after recovery The recovery id is used to handle multiple concurrent block recoveries.
ReplicaWaitingToBeRecovered	This class represents a replica that is waiting to be recovered.
ReportBadBlockAction	ReportBadBlockAction is an instruction issued by {{BPOfferService}} to {{BPServiceActor}} to report bad block to namenode
SecureDataNodeStarter	Utility class to start a datanode in a secure cluster, first obtaining privileged resources before main startup and handing them to the datanode.
SecureDataNodeStarter.SecureResources	Stash necessary resources needed for datanode operation in a secure env.
ShortCircuitRegistry	Manages client short-circuit memory segments on the DataNode.
ShortCircuitRegistry.NewShmInfo
ShortCircuitRegistry.RegisteredShm
VolumeScanner	VolumeScanner scans a single volume.

Enum Summary

Enum	Description
DataNodeLayoutVersion.Feature	Enums for features that change the layout version.

Exception Summary

Exception	Description
BPServiceActorActionException
ReplicaAlreadyExistsException	Exception indicating that the target block already exists and is not set to be recovered/overwritten.
UnexpectedReplicaStateException	Exception indicating that the replica is in an unexpected state