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

Class HostConfigManager

java.lang.Object

org.apache.hadoop.hdfs.server.blockmanagement.HostConfigManager

All Implemented Interfaces:

org.apache.hadoop.conf.Configurable

Direct Known Subclasses:

CombinedHostFileManager, HostFileManager

@Private
@Unstable
public abstract class HostConfigManager
extends Object
implements org.apache.hadoop.conf.Configurable

This interface abstracts how datanode configuration is managed. Each implementation defines its own way to persist the configuration. For example, it can use one JSON file to store the configs for all datanodes; or it can use one file to store in-service datanodes and another file to store decommission-requested datanodes. These files control which DataNodes the NameNode expects to see in the cluster.

Constructor Summary

Constructors

Constructor	Description
HostConfigManager()

Method Summary

Modifier and Type	Method	Description
abstract Iterable<InetSocketAddress>	getExcludes()	Return all datanodes that should be in decommissioned state.
abstract Iterable<InetSocketAddress>	getIncludes()	Return all the datanodes that are allowed to connect to the namenode.
abstract long	getMaintenanceExpirationTimeInMS(org.apache.hadoop.hdfs.protocol.DatanodeID dn)	Get the maintenance expiration time in milli seconds.
abstract String	getUpgradeDomain(org.apache.hadoop.hdfs.protocol.DatanodeID dn)	Get the upgrade domain of a datanode.
abstract boolean	isExcluded(org.apache.hadoop.hdfs.protocol.DatanodeID dn)	Check if a datanode needs to be decommissioned.
abstract boolean	isIncluded(org.apache.hadoop.hdfs.protocol.DatanodeID dn)	Check if a datanode is allowed to connect the namenode.
abstract void	refresh()	Reload the configuration.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.hadoop.conf.Configurable

getConf, setConf

Constructor Details

HostConfigManager

public HostConfigManager()

Method Details

getIncludes

public abstract Iterable<InetSocketAddress> getIncludes()

Return all the datanodes that are allowed to connect to the namenode.

Returns:

Iterable of all datanodes

getExcludes

public abstract Iterable<InetSocketAddress> getExcludes()

Return all datanodes that should be in decommissioned state.

Returns:

Iterable of those datanodes

isIncluded

public abstract boolean isIncluded(org.apache.hadoop.hdfs.protocol.DatanodeID dn)

Check if a datanode is allowed to connect the namenode.

Parameters:

dn - the DatanodeID of the datanode

Returns:

boolean if dn is allowed to connect the namenode.

isExcluded

public abstract boolean isExcluded(org.apache.hadoop.hdfs.protocol.DatanodeID dn)

Check if a datanode needs to be decommissioned.

Parameters:

dn - the DatanodeID of the datanode

Returns:

boolean if dn needs to be decommissioned.

refresh

public abstract void refresh()
                      throws IOException

Reload the configuration.

Throws:

IOException

getUpgradeDomain

public abstract String getUpgradeDomain(org.apache.hadoop.hdfs.protocol.DatanodeID dn)

Get the upgrade domain of a datanode.

Parameters:

dn - the DatanodeID of the datanode

Returns:

the upgrade domain of dn.

getMaintenanceExpirationTimeInMS

public abstract long getMaintenanceExpirationTimeInMS(org.apache.hadoop.hdfs.protocol.DatanodeID dn)

Get the maintenance expiration time in milli seconds.

Parameters:

dn - the DatanodeID of the datanode

Returns:

the maintenance expiration time of dn.