org.apache.hadoop.hdfs.server.namenode

Class BackupNode

java.lang.Object

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

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

@InterfaceAudience.Private
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, conf, DEFAULT_PORT, httpServer, LOG, NAMENODE_SPECIFIC_KEYS, NAMESERVICE_SPECIFIC_KEYS, namesystem, nodeRegistration, role, STANDBY_STATE, stateChangeLog, stopRequested

Method Summary

Methods

Modifier and Type	Method and Description
protected NameNode.NameNodeHAContext	createHAContext()
protected HAState	createHAState()
protected org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer	createRpcServer(Configuration conf) Create the RPC server implementation.
protected InetSocketAddress	getHttpServerAddress(Configuration conf)
protected String	getNameServiceId(Configuration conf) Get the name service Id for the node
protected InetSocketAddress	getRpcServerAddress(Configuration conf)
protected InetSocketAddress	getServiceRpcServerAddress(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(Configuration conf) Initialize name-node.
protected void	loadNamesystem(Configuration conf)
protected void	setHttpServerAddress(Configuration conf)
protected void	setRpcServerAddress(Configuration conf, InetSocketAddress addr)
protected void	setRpcServiceServerAddress(Configuration conf, InetSocketAddress addr) Modifies the configuration passed to contain the service rpc address setting
boolean	setSafeMode(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, createNameNode, doImmediateShutdown, format, getAddress, getAddress, getAddress, getFSImage, getHttpAddress, getHttpAddress, getNameNodeAddress, getNameNodeAddressHostPortString, getNameNodeMetrics, getNamesystem, getProtocolVersion, getRemoteUser, getRole, getRpcServer, getRpcServerBindHost, getServiceAddress, getServiceRpcAddress, getServiceRpcServerBindHost, getStartupProgress, getUri, initializeGenericKeys, initializeSharedEdits, initializeSharedEdits, isInSafeMode, isStandbyState, join, main, setServiceAddress, validateConfigurationSettings

Methods inherited from class java.lang.Object

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

Method Detail

getRpcServerAddress

protected InetSocketAddress getRpcServerAddress(Configuration conf)

Overrides:

getRpcServerAddress in class NameNode

getServiceRpcServerAddress

protected InetSocketAddress getServiceRpcServerAddress(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(Configuration conf,
                       InetSocketAddress addr)

Overrides:

setRpcServerAddress in class NameNode

setRpcServiceServerAddress

protected void setRpcServiceServerAddress(Configuration conf,
                              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 InetSocketAddress getHttpServerAddress(Configuration conf)

Overrides:

getHttpServerAddress in class NameNode

setHttpServerAddress

protected void setHttpServerAddress(Configuration conf)

Overrides:

setHttpServerAddress in class NameNode

loadNamesystem

protected void loadNamesystem(Configuration conf)
                       throws IOException

Overrides:

loadNamesystem in class NameNode

Throws:

IOException

initialize

protected void initialize(Configuration conf)
                   throws IOException

Description copied from class: NameNode

Initialize name-node.

Overrides:

initialize in class NameNode

Parameters:

conf - the configuration

Throws:

IOException

createRpcServer

protected org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer createRpcServer(Configuration conf)
                                                                            throws 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:

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(HdfsConstants.SafeModeAction action)
                    throws IOException

Throws:

IOException

getNameServiceId

protected String getNameServiceId(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()

Overrides:

createHAState in class NameNode

createHAContext

protected NameNode.NameNodeHAContext createHAContext()

Overrides:

createHAContext in class NameNode