Package org.apache.hadoop.hdfs.server.balancer

package org.apache.hadoop.hdfs.server.balancer

The Balancer is a tool for balancing the data across the storage devices of an HDFS cluster. Over time, the data in the HDFS storage can become skewed, The Balancer moves data blocks between DataNodes to balance data distribution.

Class	Description
Balancer	The balancer is a tool that balances disk space usage on an HDFS cluster when some datanodes become full or when new empty nodes join the cluster.
BalancerHttpServer
BalancerMXBean
Dispatcher	Dispatching block replica moves between datanodes.
Dispatcher.DBlock	A class for keeping track of block locations in the dispatcher.
Dispatcher.DBlockStriped
Dispatcher.DDatanode	A class that keeps track of a datanode.
Dispatcher.StorageGroupMap<G extends Dispatcher.DDatanode.StorageGroup>
ExitStatus	Exit status - The values associated with each exit status is directly mapped to the process's exit code in command line.
KeyManager	The class provides utilities for key and token management.
Matcher	A matcher interface for matching nodes.
MovedBlocks<L>	This window makes sure to keep blocks that have been moved within a fixed time interval (default is 1.5 hour).
MovedBlocks.Locations<L>	A class for keeping track of a block and its locations
NameNodeConnector	The class provides utilities for accessing a NameNode.