Package org.apache.hadoop.hdfs.server.blockmanagement

Interface Summary

Interface	Description
BlockCollection	This interface is used by the block manager to expose a few characteristics of a collection of Block/BlockUnderConstruction.
BlockPlacementStatus
BlockStatsMXBean	This is an interface used to retrieve statistic information related to block management.
DatanodeAdminMonitorInterface	Interface used to implement a decommission and maintenance monitor class, which is instantiated by the DatanodeAdminManager class.
DatanodeStatistics	Datanode statistics
FSClusterStats	This interface is used for retrieving the load related statistics of the cluster.

Class Summary

Class	Description
AvailableSpaceBlockPlacementPolicy	Space balanced block placement policy.
AvailableSpaceRackFaultTolerantBlockPlacementPolicy	Space balanced rack fault tolerant block placement policy.
BlockIdManager	BlockIdManager allocates the generation stamps and the block ID.
BlockInfo	For a given block (or an erasure coding block group), BlockInfo class maintains 1) the BlockCollection it is part of, and 2) datanodes where the replicas of the block, or blocks belonging to the erasure coding block group, are stored.
BlockInfoContiguous	Subclass of BlockInfo, used for a block with replication scheme.
BlockInfoStriped	Subclass of BlockInfo, presenting a block group in erasure coding.
BlockInfoStriped.StorageAndBlockIndex	This class contains datanode storage information and block index in the block group.
BlockManager	Keeps information related to the blocks stored in the Hadoop cluster.
BlockManagerFaultInjector	Used to inject certain faults for testing.
BlockPlacementPolicies
BlockPlacementPolicy	This interface is used for choosing the desired number of targets for placing block replicas.
BlockPlacementPolicyDefault	The class is responsible for choosing the desired number of targets for placing block replicas.
BlockPlacementPolicyRackFaultTolerant	The class is responsible for choosing the desired number of targets for placing block replicas.
BlockPlacementPolicyWithNodeGroup	The class is responsible for choosing the desired number of targets for placing block replicas on environment with node-group layer.
BlockPlacementPolicyWithUpgradeDomain	The class is responsible for choosing the desired number of targets for placing block replicas that honors upgrade domain policy.
BlockPlacementStatusDefault
BlockPlacementStatusWithNodeGroup	An implementation of @see BlockPlacementStatus for
BlockPlacementStatusWithUpgradeDomain	An implementation of @see BlockPlacementStatus for
BlockStoragePolicySuite	A collection of block storage policies.
BlockUnderConstructionFeature	Represents the under construction feature of a Block.
CacheReplicationMonitor	Scans the namesystem, scheduling blocks to be cached as appropriate.
CombinedHostFileManager	This class manages datanode configuration using a json file.
CorruptReplicasMap	Stores information about all corrupt blocks in the File System.
DatanodeAdminBackoffMonitor	This class implements the logic to track decommissioning and entering maintenance nodes, ensure all their blocks are adequately replicated before they are moved to the decommissioned or maintenance state.
DatanodeAdminDefaultMonitor	Checks to see if datanodes have finished DECOMMISSION_INPROGRESS or ENTERING_MAINTENANCE state.
DatanodeAdminManager	Manages decommissioning and maintenance state for DataNodes.
DatanodeAdminMonitorBase	This abstract class provides some base methods which are inherited by the DatanodeAdmin BackOff and Default Monitors, which control decommission and maintenance mode.
DatanodeDescriptor	This class extends the DatanodeInfo class with ephemeral information (eg health, capacity, what blocks are associated with the Datanode) that is private to the Namenode, ie this class is not exposed to clients.
DatanodeDescriptor.BlockTargetPair	Block and targets pair
DatanodeDescriptor.CachedBlocksList	A list of CachedBlock objects on this datanode.
DatanodeManager	Manage datanodes, include decommission and other activities.
DatanodeStorageInfo	A Datanode has one or more storages.
HostConfigManager	This interface abstracts how datanode configuration is managed.
HostFileManager	This class manages the include and exclude files for HDFS.
HostSet	The HostSet allows efficient queries on matching wildcard addresses.
NumberReplicas	A immutable object that stores the number of live replicas and the number of decommissioned Replicas.
ProvidedStorageMap	This class allows us to manage and multiplex between storages local to datanodes, and provided storage.
ProvidedStorageMap.ProvidedDescriptor	An abstract DatanodeDescriptor to track datanodes with provided storages.
SequentialBlockGroupIdGenerator	Generate the next valid block group ID by incrementing the maximum block group ID allocated so far, with the first 2^10 block group IDs reserved.
SequentialBlockIdGenerator	Generate the next valid block ID by incrementing the maximum block ID allocated so far, starting at 2^30+1.
SlowDiskTracker	This class aggregates information from SlowDiskReports received via heartbeats.
SlowDiskTracker.DiskLatency	This structure is a thin wrapper over disk latencies.
SlowPeerDisabledTracker	Disabled tracker for slow peers.
SlowPeerTracker	This class aggregates information from SlowPeerReports received via heartbeats.
StorageTypeStats	Statistics per StorageType.

Enum Summary

Enum	Description
CorruptReplicasMap.Reason	The corruption reason code
DatanodeDescriptor.CachedBlocksList.Type
NumberReplicas.StoredReplicaState

Exception Summary

Exception	Description
BlockPlacementPolicy.NotEnoughReplicasException
OutOfLegacyGenerationStampsException	This exception is thrown when the name node runs out of V1 (legacy) generation stamps.
UnresolvedTopologyException	This exception is thrown if resolving topology path for a node fails.