Package org.apache.hadoop.hdfs.server.namenode

Class BackupNode

java.lang.Object

org.apache.hadoop.conf.Configured

org.apache.hadoop.conf.ReconfigurableBase

org.apache.hadoop.hdfs.server.namenode.NameNode

org.apache.hadoop.hdfs.server.namenode.BackupNode

All Implemented Interfaces:

org.apache.hadoop.conf.Configurable, org.apache.hadoop.conf.Reconfigurable, TokenVerifier<org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier>, NameNodeStatusMXBean

@Private
@Metrics(context="dfs")
public class BackupNode
extends NameNode

BackupNode.

Backup node can play two roles.

1. HdfsServerConstants.NamenodeRole.CHECKPOINT node periodically creates checkpoints, that is downloads image and edits from the active node, merges them, and uploads the new image back to the active.
2. HdfsServerConstants.NamenodeRole.BACKUP node keeps its namespace in sync with the active node, and periodically creates checkpoints by simply saving the namespace image to local disk(s).

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.hdfs.server.namenode.NameNode

NameNode.NameNodeHAContext, NameNode.OperationCategory

Field Summary

Fields inherited from class org.apache.hadoop.hdfs.server.namenode.NameNode

ACTIVE_STATE, allowStaleStandbyReads, blockStateChangeLog, DEFAULT_PORT, httpServer, LOG, METRICS_LOG_NAME, NAMENODE_SPECIFIC_KEYS, NAMESERVICE_SPECIFIC_KEYS, namesystem, nodeRegistration, OBSERVER_STATE, role, STANDBY_STATE, stateChangeLog, stopRequested, tracer

Method Summary

Modifier and Type	Method	Description
protected NameNode.NameNodeHAContext	createHAContext()
protected HAState	createHAState(org.apache.hadoop.conf.Configuration conf)
protected NameNodeRpcServer	createRpcServer(org.apache.hadoop.conf.Configuration conf)	Create the RPC server implementation.
protected java.net.InetSocketAddress	getHttpServerAddress(org.apache.hadoop.conf.Configuration conf)
protected java.lang.String	getNameServiceId(org.apache.hadoop.conf.Configuration conf)	Get the name service Id for the node
protected java.net.InetSocketAddress	getRpcServerAddress(org.apache.hadoop.conf.Configuration conf)
protected java.net.InetSocketAddress	getServiceRpcServerAddress(org.apache.hadoop.conf.Configuration conf)	Given a configuration get the address of the service rpc server If the service rpc is not configured returns null
protected void	initialize(org.apache.hadoop.conf.Configuration conf)	Initialize name-node.
protected void	loadNamesystem(org.apache.hadoop.conf.Configuration conf)
protected void	setRpcServerAddress(org.apache.hadoop.conf.Configuration conf, java.net.InetSocketAddress addr)
protected void	setRpcServiceServerAddress(org.apache.hadoop.conf.Configuration conf, java.net.InetSocketAddress addr)	Modifies the configuration passed to contain the service rpc address setting
boolean	setSafeMode(org.apache.hadoop.hdfs.protocol.HdfsConstants.SafeModeAction action)
void	stop()	Stop all NameNode threads and wait for all to finish.

Methods inherited from class org.apache.hadoop.hdfs.server.namenode.NameNode

checkAllowFormat, composeNotStartedMessage, createNameNode, doImmediateShutdown, doRollback, format, getAliasMapServer, getAuxiliaryNameNodeAddresses, getBytesWithFutureGenerationStamps, getClientIdAndCallId, getClientMachine, getClientNamenodeAddress, getFSImage, getHostAndPort, getHttpAddress, getHttpAddress, getHttpsAddress, getHttpServer, getHttpServerBindAddress, getLastHATransitionTime, getNameNodeAddress, getNameNodeAddressHostPortString, getNameNodeMetrics, getNameNodeState, getNamesystem, getNewConf, getNNAuxiliaryRpcAddress, getNNRole, getProtocolVersion, getReconfigurableProperties, getRemoteUser, getRole, getRpcServer, getRpcServerBindHost, getServiceAddress, getServiceRpcAddress, getServiceRpcServerBindHost, getSlowDisksReport, getSlowPeersReport, getStartupOption, getStartupProgress, getState, getTokenServiceName, initializeGenericKeys, initializeSharedEdits, initializeSharedEdits, initMetrics, isActiveState, isInSafeMode, isObserverState, isSecurityEnabled, isStandbyState, join, joinHttpServer, main, parseSpecialValue, queueExternalCall, reconfigurePropertyImpl, setServiceAddress, startMetricsLogger, stopMetricsLogger, verifyToken

Methods inherited from class org.apache.hadoop.conf.ReconfigurableBase

getChangedProperties, getReconfigurationTaskStatus, isPropertyReconfigurable, reconfigureProperty, setReconfigurationUtil, shutdownReconfigurationTask, startReconfigurationTask

Methods inherited from class org.apache.hadoop.conf.Configured

getConf, setConf

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

Method Detail

getRpcServerAddress

protected java.net.InetSocketAddress getRpcServerAddress(org.apache.hadoop.conf.Configuration conf)

Overrides:

getRpcServerAddress in class NameNode

getServiceRpcServerAddress

protected java.net.InetSocketAddress getServiceRpcServerAddress(org.apache.hadoop.conf.Configuration conf)

Description copied from class: NameNode

Given a configuration get the address of the service rpc server If the service rpc is not configured returns null

Overrides:

getServiceRpcServerAddress in class NameNode

setRpcServerAddress

protected void setRpcServerAddress(org.apache.hadoop.conf.Configuration conf,
                                   java.net.InetSocketAddress addr)

Overrides:

setRpcServerAddress in class NameNode

setRpcServiceServerAddress

protected void setRpcServiceServerAddress(org.apache.hadoop.conf.Configuration conf,
                                          java.net.InetSocketAddress addr)

Description copied from class: NameNode

Modifies the configuration passed to contain the service rpc address setting

Overrides:

setRpcServiceServerAddress in class NameNode

getHttpServerAddress

protected java.net.InetSocketAddress getHttpServerAddress(org.apache.hadoop.conf.Configuration conf)

Overrides:

getHttpServerAddress in class NameNode

loadNamesystem

protected void loadNamesystem(org.apache.hadoop.conf.Configuration conf)
                       throws java.io.IOException

Overrides:

loadNamesystem in class NameNode

Throws:

java.io.IOException

initialize

protected void initialize(org.apache.hadoop.conf.Configuration conf)
                   throws java.io.IOException

Description copied from class: NameNode

Initialize name-node.

Overrides:

initialize in class NameNode

Parameters:

conf - the configuration

Throws:

java.io.IOException

createRpcServer

protected NameNodeRpcServer createRpcServer(org.apache.hadoop.conf.Configuration conf)
                                     throws java.io.IOException

Description copied from class: NameNode

Create the RPC server implementation. Used as an extension point for the BackupNode.

Overrides:

createRpcServer in class NameNode

Throws:

java.io.IOException

stop

public void stop()

Description copied from class: NameNode

Stop all NameNode threads and wait for all to finish.

Overrides:

stop in class NameNode

setSafeMode

public boolean setSafeMode(org.apache.hadoop.hdfs.protocol.HdfsConstants.SafeModeAction action)
                    throws java.io.IOException

Throws:

java.io.IOException

getNameServiceId

protected java.lang.String getNameServiceId(org.apache.hadoop.conf.Configuration conf)

Description copied from class: NameNode

Get the name service Id for the node

Overrides:

getNameServiceId in class NameNode

Returns:

name service Id or null if federation is not configured

createHAState

protected HAState createHAState(org.apache.hadoop.conf.Configuration conf)

Overrides:

createHAState in class NameNode

createHAContext

protected NameNode.NameNodeHAContext createHAContext()

Overrides:

createHAContext in class NameNode