org.apache.hadoop.net

Class TableMapping

java.lang.Object

org.apache.hadoop.net.AbstractDNSToSwitchMapping

org.apache.hadoop.net.CachedDNSToSwitchMapping

org.apache.hadoop.net.TableMapping

All Implemented Interfaces:

Configurable, DNSToSwitchMapping

@InterfaceAudience.Public
@InterfaceStability.Evolving
public class TableMapping
extends CachedDNSToSwitchMapping

Simple DNSToSwitchMapping implementation that reads a 2 column text file. The columns are separated by whitespace. The first column is a DNS or IP address and the second column specifies the rack where the address maps.

This class uses the configuration parameter net.topology.table.file.name to locate the mapping file.

Calls to CachedDNSToSwitchMapping.resolve(List) will look up the address as defined in the mapping file. If no entry corresponding to the address is found, the value /default-rack is returned.

Field Summary

Fields inherited from class org.apache.hadoop.net.CachedDNSToSwitchMapping

rawMapping

Constructor Summary

Constructors

Constructor and Description
TableMapping()

Method Summary

Methods

Modifier and Type	Method and Description
Configuration	getConf() Return the configuration used by this object.
void	reloadCachedMappings() Reload all of the cached mappings.
void	setConf(Configuration conf) Set the configuration to be used by this object.

Methods inherited from class org.apache.hadoop.net.CachedDNSToSwitchMapping

getSwitchMap, isSingleSwitch, reloadCachedMappings, resolve, toString

Methods inherited from class org.apache.hadoop.net.AbstractDNSToSwitchMapping

dumpTopology, isMappingSingleSwitch, isSingleSwitchByScriptPolicy

Methods inherited from class java.lang.Object

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

Constructor Detail

TableMapping

public TableMapping()

Method Detail

getConf

public Configuration getConf()

Description copied from interface: Configurable

Return the configuration used by this object.

Specified by:

getConf in interface Configurable

Overrides:

getConf in class AbstractDNSToSwitchMapping

setConf

public void setConf(Configuration conf)

Description copied from interface: Configurable

Set the configuration to be used by this object.

Specified by:

setConf in interface Configurable

Overrides:

setConf in class AbstractDNSToSwitchMapping

reloadCachedMappings

public void reloadCachedMappings()

Description copied from interface: DNSToSwitchMapping

Reload all of the cached mappings. If there is a cache, this method will clear it, so that future accesses will get a chance to see the new data.

Specified by:

reloadCachedMappings in interface DNSToSwitchMapping

Overrides:

reloadCachedMappings in class CachedDNSToSwitchMapping