NameNode (Apache Hadoop HDFS 3.4.1.100-eep-941 API)

java.lang.Object
- org.apache.hadoop.conf.Configured
- - org.apache.hadoop.conf.ReconfigurableBase
  - - org.apache.hadoop.hdfs.server.namenode.NameNode

All Implemented Interfaces:

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

Direct Known Subclasses:

BackupNode
```
@Private
@Metrics(context="dfs")
public class NameNode
extends org.apache.hadoop.conf.ReconfigurableBase
implements NameNodeStatusMXBean, TokenVerifier<org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier>
```
NameNode serves as both directory namespace manager and "inode table" for the Hadoop DFS. There is a single NameNode running in any DFS deployment. (Well, except when there is a second backup/failover NameNode, or when using federated NameNodes.) The NameNode controls two critical tables: 1) filename->blocksequence (namespace) 2) block->machinelist ("inodes") The first table is stored on disk and is very precious. The second table is rebuilt every time the NameNode comes up. 'NameNode' refers to both this class as well as the 'NameNode server'. The 'FSNamesystem' class actually performs most of the filesystem management. The majority of the 'NameNode' class itself is concerned with exposing the IPC interface and the HTTP server to the outside world, plus some configuration management. NameNode implements the ClientProtocol interface, which allows clients to ask for DFS services. ClientProtocol is not designed for direct use by authors of DFS client code. End-users should instead use the FileSystem class. NameNode also implements the DatanodeProtocol interface, used by DataNodes that actually store DFS data blocks. These methods are invoked repeatedly and automatically by all the DataNodes in a DFS deployment. NameNode also implements the NamenodeProtocol interface, used by secondary namenodes or rebalancing processes to get partial NameNode state, for example partial blocksMap etc.

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`protected class`	`NameNode.NameNodeHAContext`	Class used to expose `NameNode` as context to `HAState`
`static class`	`NameNode.OperationCategory`	Categories of operations supported by the namenode.

Field Summary

Fields
Modifier and Type	Field	Description
`static HAState`	`ACTIVE_STATE`
`protected boolean`	`allowStaleStandbyReads`
`static org.slf4j.Logger`	`blockStateChangeLog`
`static int`	`DEFAULT_PORT`	Deprecated. Use `HdfsClientConfigKeys.DFS_NAMENODE_RPC_PORT_DEFAULT` instead.
`protected NameNodeHttpServer`	`httpServer`	httpServer
`static org.slf4j.Logger`	`LOG`
`static java.lang.String`	`METRICS_LOG_NAME`
`static java.lang.String[]`	`NAMENODE_SPECIFIC_KEYS`	HDFS configuration can have three types of parameters: Parameters that are common for all the name services in the cluster. Parameters that are specific to a name service.
`static java.lang.String[]`	`NAMESERVICE_SPECIFIC_KEYS`
`protected FSNamesystem`	`namesystem`
`protected NamenodeRegistration`	`nodeRegistration`	Registration information of this name-node
`static HAState`	`OBSERVER_STATE`
`protected HdfsServerConstants.NamenodeRole`	`role`
`static HAState`	`STANDBY_STATE`
`static org.slf4j.Logger`	`stateChangeLog`
`protected boolean`	`stopRequested`	only used for testing purposes
`protected org.apache.hadoop.tracing.Tracer`	`tracer`

Constructor Summary

Constructors
Modifier	Constructor	Description
	`NameNode(org.apache.hadoop.conf.Configuration conf)`	Start NameNode.
`protected`	`NameNode(org.apache.hadoop.conf.Configuration conf, HdfsServerConstants.NamenodeRole role)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`static void`	`checkAllowFormat(org.apache.hadoop.conf.Configuration conf)`
`static java.lang.String`	`composeNotStartedMessage(HdfsServerConstants.NamenodeRole role)`
`protected HAContext`	`createHAContext()`
`protected HAState`	`createHAState(org.apache.hadoop.conf.Configuration conf)`
`static NameNode`	`createNameNode(java.lang.String[] argv, org.apache.hadoop.conf.Configuration conf)`
`protected NameNodeRpcServer`	`createRpcServer(org.apache.hadoop.conf.Configuration conf)`	Create the RPC server implementation.
`protected void`	`doImmediateShutdown(java.lang.Throwable t)`	Shutdown the NN immediately in an ungraceful way.
`static boolean`	`doRollback(org.apache.hadoop.conf.Configuration conf, boolean isConfirmationNeeded)`
`static void`	`format(org.apache.hadoop.conf.Configuration conf)`	Format a new filesystem.
`InMemoryLevelDBAliasMapServer`	`getAliasMapServer()`
`java.util.Set<java.net.InetSocketAddress>`	`getAuxiliaryNameNodeAddresses()`
`long`	`getBytesWithFutureGenerationStamps()`	Gets number of bytes in blocks with future generation stamps.
`static org.apache.commons.lang3.tuple.Pair<byte[],java.lang.Integer>`	`getClientIdAndCallId(java.lang.String[] ipProxyUsers)`	Try to obtain the actual client's id and call id according to the current user.
`static java.lang.String`	`getClientMachine(java.lang.String[] ipProxyUsers)`	Try to obtain the actual client's machine according to the current user.
`java.lang.String`	`getClientNamenodeAddress()`	Get the namenode address to be used by clients.
`FSImage`	`getFSImage()`	get FSImage
`java.lang.String`	`getHostAndPort()`	Gets the host and port colon separated.
`java.net.InetSocketAddress`	`getHttpAddress()`
`static java.net.InetSocketAddress`	`getHttpAddress(org.apache.hadoop.conf.Configuration conf)`
`java.net.InetSocketAddress`	`getHttpsAddress()`
`org.apache.hadoop.http.HttpServer2`	`getHttpServer()`
`protected java.net.InetSocketAddress`	`getHttpServerAddress(org.apache.hadoop.conf.Configuration conf)`
`protected java.net.InetSocketAddress`	`getHttpServerBindAddress(org.apache.hadoop.conf.Configuration conf)`	HTTP server address for binding the endpoint.
`long`	`getLastHATransitionTime()`	Gets the most recent HA transition time in milliseconds from the epoch.
`java.net.InetSocketAddress`	`getNameNodeAddress()`
`java.lang.String`	`getNameNodeAddressHostPortString()`
`static NameNodeMetrics`	`getNameNodeMetrics()`
`int`	`getNameNodeState()`	Emit Namenode HA service state as an integer so that one can monitor NN HA state based on this metric.
`protected java.lang.String`	`getNameServiceId(org.apache.hadoop.conf.Configuration conf)`	Get the name service Id for the node
`FSNamesystem`	`getNamesystem()`	Return the `FSNamesystem` object.
`protected org.apache.hadoop.conf.Configuration`	`getNewConf()`
`java.lang.String`	`getNNAuxiliaryRpcAddress()`	Return a host:port format string corresponds to an auxiliary port configured on NameNode.
`java.lang.String`	`getNNRole()`	Gets the NameNode role.
`long`	`getProtocolVersion(java.lang.String protocol, long clientVersion)`
`java.util.Collection<java.lang.String>`	`getReconfigurableProperties()`
`static org.apache.hadoop.security.UserGroupInformation`	`getRemoteUser()`
`HdfsServerConstants.NamenodeRole`	`getRole()`
`NamenodeProtocols`	`getRpcServer()`
`protected java.net.InetSocketAddress`	`getRpcServerAddress(org.apache.hadoop.conf.Configuration conf)`
`protected java.lang.String`	`getRpcServerBindHost(org.apache.hadoop.conf.Configuration conf)`	Given a configuration get the bind host of the client rpc server If the bind host is not configured returns null.
`static java.net.InetSocketAddress`	`getServiceAddress(org.apache.hadoop.conf.Configuration conf, boolean fallback)`	Fetches the address for services to use when connecting to namenode based on the value of fallback returns null if the special address is not specified or returns the default namenode address to be used by both clients and services.
`java.net.InetSocketAddress`	`getServiceRpcAddress()`
`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 java.lang.String`	`getServiceRpcServerBindHost(org.apache.hadoop.conf.Configuration conf)`	Given a configuration get the bind host of the service rpc server If the bind host is not configured returns null.
`java.lang.String`	`getSlowDisksReport()`	Gets the topN slow disks in the cluster, if the feature is enabled.
`java.lang.String`	`getSlowPeersReport()`	Retrieves information about slow DataNodes, if the feature is enabled.
`static HdfsServerConstants.StartupOption`	`getStartupOption(org.apache.hadoop.conf.Configuration conf)`
`static StartupProgress`	`getStartupProgress()`	Returns object used for reporting namenode startup progress.
`java.lang.String`	`getState()`	Gets the NameNode state.
`java.lang.String`	`getTokenServiceName()`	Return the service name of the issued delegation token.
`protected void`	`initialize(org.apache.hadoop.conf.Configuration conf)`	Initialize name-node.
`static void`	`initializeGenericKeys(org.apache.hadoop.conf.Configuration conf, java.lang.String nameserviceId, java.lang.String namenodeId)`	In federation configuration is set for a set of namenode and secondary namenode/backup/checkpointer, which are grouped under a logical nameservice ID.
`static boolean`	`initializeSharedEdits(org.apache.hadoop.conf.Configuration conf)`
`static boolean`	`initializeSharedEdits(org.apache.hadoop.conf.Configuration conf, boolean force)`
`static void`	`initMetrics(org.apache.hadoop.conf.Configuration conf, HdfsServerConstants.NamenodeRole role)`
`boolean`	`isActiveState()`
`boolean`	`isInSafeMode()`	Is the cluster currently in safe mode?
`boolean`	`isObserverState()`
`boolean`	`isSecurityEnabled()`	Gets if security is enabled.
`boolean`	`isStandbyState()`
`void`	`join()`	Wait for service to finish.
`void`	`joinHttpServer()`	NameNodeHttpServer, used by unit tests to ensure a full shutdown, so that no bind exception is thrown during restart.
`protected void`	`loadNamesystem(org.apache.hadoop.conf.Configuration conf)`
`static void`	`main(java.lang.String[] argv)`
`static java.lang.String`	`parseSpecialValue(java.lang.String content, java.lang.String key)`	Try to obtain the value corresponding to the key by parsing the content.
`void`	`queueExternalCall(org.apache.hadoop.ipc.ExternalCall<?> extCall)`
`protected java.lang.String`	`reconfigurePropertyImpl(java.lang.String property, java.lang.String newVal)`
`protected void`	`setRpcServerAddress(org.apache.hadoop.conf.Configuration conf, java.net.InetSocketAddress rpcAddress)`
`protected void`	`setRpcServiceServerAddress(org.apache.hadoop.conf.Configuration conf, java.net.InetSocketAddress serviceRPCAddress)`	Modifies the configuration passed to contain the service rpc address setting
`static void`	`setServiceAddress(org.apache.hadoop.conf.Configuration conf, java.lang.String address)`	Set the configuration property for the service rpc address to address
`protected void`	`startMetricsLogger(org.apache.hadoop.conf.Configuration conf)`	Start a timer to periodically write NameNode metrics to the log file.
`void`	`stop()`	Stop all NameNode threads and wait for all to finish.
`protected void`	`stopMetricsLogger()`
`void`	`verifyToken(org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier id, byte[] password)`

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

- Field Detail
  - NAMENODE_SPECIFIC_KEYS
```
public static final java.lang.String[] NAMENODE_SPECIFIC_KEYS
```
    HDFS configuration can have three types of parameters:
    1. Parameters that are common for all the name services in the cluster.
    2. Parameters that are specific to a name service. These keys are suffixed with nameserviceId in the configuration. For example, "dfs.namenode.rpc-address.nameservice1".
    3. Parameters that are specific to a single name node. These keys are suffixed with nameserviceId and namenodeId in the configuration. for example, "dfs.namenode.rpc-address.nameservice1.namenode1"
    In the latter cases, operators may specify the configuration without any suffix, with a nameservice suffix, or with a nameservice and namenode suffix. The more specific suffix will take precedence. These keys are specific to a given namenode, and thus may be configured globally, for a nameservice, or for a specific namenode within a nameservice.
  - NAMESERVICE_SPECIFIC_KEYS
```
public static final java.lang.String[] NAMESERVICE_SPECIFIC_KEYS
```
    See Also:
    
    These keys are specific to a nameservice, but may not be overridden for a specific namenode.
  - DEFAULT_PORT
```
@Deprecated
public static final int DEFAULT_PORT
```
    Deprecated.
    Use HdfsClientConfigKeys.DFS_NAMENODE_RPC_PORT_DEFAULT instead.
    
    See Also:
    
    Constant Field Values
  - LOG
```
public static final org.slf4j.Logger LOG
```
  - stateChangeLog
```
public static final org.slf4j.Logger stateChangeLog
```
  - blockStateChangeLog
```
public static final org.slf4j.Logger blockStateChangeLog
```
  - ACTIVE_STATE
```
public static final HAState ACTIVE_STATE
```
  - STANDBY_STATE
```
public static final HAState STANDBY_STATE
```
  - OBSERVER_STATE
```
public static final HAState OBSERVER_STATE
```
  - METRICS_LOG_NAME
```
public static final java.lang.String METRICS_LOG_NAME
```
    See Also:
    
    Constant Field Values
  - namesystem
```
protected FSNamesystem namesystem
```
  - role
```
protected final HdfsServerConstants.NamenodeRole role
```
  - allowStaleStandbyReads
```
protected final boolean allowStaleStandbyReads
```
  - httpServer
```
protected NameNodeHttpServer httpServer
```
    httpServer
  - stopRequested
```
protected boolean stopRequested
```
    only used for testing purposes
  - nodeRegistration
```
protected NamenodeRegistration nodeRegistration
```
    Registration information of this name-node
  - tracer
```
protected final org.apache.hadoop.tracing.Tracer tracer
```
- Constructor Detail
  - NameNode
```
public NameNode(org.apache.hadoop.conf.Configuration conf)
         throws java.io.IOException
```
    Start NameNode.
    The name-node can be started with one of the following startup options:
    - REGULAR - normal name node startup
    - FORMAT - format name node
    - BACKUP - start backup node
    - CHECKPOINT - start checkpoint node
    - UPGRADE - start the cluster
    - UPGRADEONLY - upgrade the cluster upgrade and create a snapshot of the current file system state
    - RECOVERY - recover name node metadata
    - ROLLBACK - roll the cluster back to the previous state
    - IMPORT - import checkpoint
    The option is passed via configuration field: dfs.namenode.startup The conf will be modified to reflect the actual ports on which the NameNode is up and running if the user passes the port as zero in the conf.
    Parameters:
    
    conf - confirguration
    
    Throws:
    
    java.io.IOException
  - NameNode
```
protected NameNode(org.apache.hadoop.conf.Configuration conf,
                   HdfsServerConstants.NamenodeRole role)
            throws java.io.IOException
```
    Throws:
    
    java.io.IOException
- Method Detail
  - getProtocolVersion
```
public long getProtocolVersion(java.lang.String protocol,
                               long clientVersion)
                        throws java.io.IOException
```
    Throws:
    
    java.io.IOException
  - format
```
public static void format(org.apache.hadoop.conf.Configuration conf)
                   throws java.io.IOException
```
    Format a new filesystem. Destroys any filesystem that may already exist at this location.
    
    Throws:
    
    java.io.IOException
  - getNamesystem
```
public FSNamesystem getNamesystem()
```
    Return the FSNamesystem object.
    
    Returns:
    
    FSNamesystem object.
  - getRpcServer
```
public NamenodeProtocols getRpcServer()
```
  - getHttpServer
```
@VisibleForTesting
public org.apache.hadoop.http.HttpServer2 getHttpServer()
```
  - queueExternalCall
```
public void queueExternalCall(org.apache.hadoop.ipc.ExternalCall<?> extCall)
                       throws java.io.IOException,
                              java.lang.InterruptedException
```
    Throws:
    
    java.io.IOException
    
    java.lang.InterruptedException
  - initMetrics
```
public static void initMetrics(org.apache.hadoop.conf.Configuration conf,
                               HdfsServerConstants.NamenodeRole role)
```
  - getNameNodeMetrics
```
public static NameNodeMetrics getNameNodeMetrics()
```
  - parseSpecialValue
```
@VisibleForTesting
public static java.lang.String parseSpecialValue(java.lang.String content,
                                                 java.lang.String key)
```
    Try to obtain the value corresponding to the key by parsing the content.
    
    Parameters:
    
    content - the full content to be parsed.
    
    key - trying to obtain the value of the key.
    
    Returns:
    
    the value corresponding to the key.
  - getClientMachine
```
public static java.lang.String getClientMachine(java.lang.String[] ipProxyUsers)
```
    Try to obtain the actual client's machine according to the current user.
    
    Parameters:
    
    ipProxyUsers - Users who can override client infos.
    
    Returns:
    
    The actual client's machine.
  - getClientIdAndCallId
```
public static org.apache.commons.lang3.tuple.Pair<byte[],java.lang.Integer> getClientIdAndCallId(java.lang.String[] ipProxyUsers)
```
    Try to obtain the actual client's id and call id according to the current user.
    
    Parameters:
    
    ipProxyUsers - Users who can override client infos
    
    Returns:
    
    The actual client's id and call id.
  - getStartupProgress
```
public static StartupProgress getStartupProgress()
```
    Returns object used for reporting namenode startup progress.
    
    Returns:
    
    StartupProgress for reporting namenode startup progress
  - getTokenServiceName
```
public java.lang.String getTokenServiceName()
```
    Return the service name of the issued delegation token.
    
    Returns:
    
    The name service id in HA-mode, or the rpc address in non-HA mode
  - getClientNamenodeAddress
```
public java.lang.String getClientNamenodeAddress()
```
    Get the namenode address to be used by clients.
    
    Returns:
    
    nn address
  - setServiceAddress
```
public static void setServiceAddress(org.apache.hadoop.conf.Configuration conf,
                                     java.lang.String address)
```
    Set the configuration property for the service rpc address to address
  - getServiceAddress
```
public static java.net.InetSocketAddress getServiceAddress(org.apache.hadoop.conf.Configuration conf,
                                                           boolean fallback)
```
    Fetches the address for services to use when connecting to namenode based on the value of fallback returns null if the special address is not specified or returns the default namenode address to be used by both clients and services. Services here are datanodes, backup node, any non client connection
  - getRole
```
public HdfsServerConstants.NamenodeRole getRole()
```
  - composeNotStartedMessage
```
public static java.lang.String composeNotStartedMessage(HdfsServerConstants.NamenodeRole role)
```
  - getServiceRpcServerAddress
```
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
  - getRpcServerAddress
```
protected java.net.InetSocketAddress getRpcServerAddress(org.apache.hadoop.conf.Configuration conf)
```
  - getServiceRpcServerBindHost
```
protected java.lang.String getServiceRpcServerBindHost(org.apache.hadoop.conf.Configuration conf)
```
    Given a configuration get the bind host of the service rpc server If the bind host is not configured returns null.
  - getRpcServerBindHost
```
protected java.lang.String getRpcServerBindHost(org.apache.hadoop.conf.Configuration conf)
```
    Given a configuration get the bind host of the client rpc server If the bind host is not configured returns null.
  - setRpcServiceServerAddress
```
protected void setRpcServiceServerAddress(org.apache.hadoop.conf.Configuration conf,
                                          java.net.InetSocketAddress serviceRPCAddress)
```
    Modifies the configuration passed to contain the service rpc address setting
  - setRpcServerAddress
```
protected void setRpcServerAddress(org.apache.hadoop.conf.Configuration conf,
                                   java.net.InetSocketAddress rpcAddress)
```
  - getHttpServerAddress
```
protected java.net.InetSocketAddress getHttpServerAddress(org.apache.hadoop.conf.Configuration conf)
```
  - getHttpServerBindAddress
```
protected java.net.InetSocketAddress getHttpServerBindAddress(org.apache.hadoop.conf.Configuration conf)
```
    HTTP server address for binding the endpoint. This method is for use by the NameNode and its derivatives. It may return a different address than the one that should be used by clients to connect to the NameNode. See DFSConfigKeys.DFS_NAMENODE_HTTP_BIND_HOST_KEY
    
    Parameters:
    
    conf -
    
    Returns:
  - getHttpAddress
```
public static java.net.InetSocketAddress getHttpAddress(org.apache.hadoop.conf.Configuration conf)
```
    Returns:
    
    the NameNode HTTP address.
  - loadNamesystem
```
protected void loadNamesystem(org.apache.hadoop.conf.Configuration conf)
                       throws java.io.IOException
```
    Throws:
    
    java.io.IOException
  - getRemoteUser
```
public static org.apache.hadoop.security.UserGroupInformation getRemoteUser()
                                                                     throws java.io.IOException
```
    Throws:
    
    java.io.IOException
  - verifyToken
```
public void verifyToken(org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier id,
                        byte[] password)
                 throws java.io.IOException
```
    Specified by:
    
    verifyToken in interface TokenVerifier<org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier>
    
    Throws:
    
    java.io.IOException
  - initialize
```
protected void initialize(org.apache.hadoop.conf.Configuration conf)
                   throws java.io.IOException
```
    Initialize name-node.
    
    Parameters:
    
    conf - the configuration
    
    Throws:
    
    java.io.IOException
  - getAliasMapServer
```
@VisibleForTesting
public InMemoryLevelDBAliasMapServer getAliasMapServer()
```
  - startMetricsLogger
```
protected void startMetricsLogger(org.apache.hadoop.conf.Configuration conf)
```
    Start a timer to periodically write NameNode metrics to the log file. This behavior can be disabled by configuration.
    
    Parameters:
    
    conf -
  - stopMetricsLogger
```
protected void stopMetricsLogger()
```
  - createRpcServer
```
protected NameNodeRpcServer createRpcServer(org.apache.hadoop.conf.Configuration conf)
                                     throws java.io.IOException
```
    Create the RPC server implementation. Used as an extension point for the BackupNode.
    
    Throws:
    
    java.io.IOException
  - createHAState
```
protected HAState createHAState(org.apache.hadoop.conf.Configuration conf)
```
  - createHAContext
```
protected HAContext createHAContext()
```
  - join
```
public void join()
```
    Wait for service to finish. (Normally, it runs forever.)
  - stop
```
public void stop()
```
    Stop all NameNode threads and wait for all to finish.
  - isInSafeMode
```
public boolean isInSafeMode()
```
    Is the cluster currently in safe mode?
  - getFSImage
```
@VisibleForTesting
public FSImage getFSImage()
```
    get FSImage
  - getNameNodeAddress
```
public java.net.InetSocketAddress getNameNodeAddress()
```
    Returns:
    
    NameNode RPC address
  - getAuxiliaryNameNodeAddresses
```
public java.util.Set<java.net.InetSocketAddress> getAuxiliaryNameNodeAddresses()
```
    Returns:
    
    The auxiliary nameNode RPC addresses, or empty set if there is none.
  - getNameNodeAddressHostPortString
```
public java.lang.String getNameNodeAddressHostPortString()
```
    Returns:
    
    NameNode RPC address in "host:port" string form
  - getNNAuxiliaryRpcAddress
```
@VisibleForTesting
public java.lang.String getNNAuxiliaryRpcAddress()
```
    Return a host:port format string corresponds to an auxiliary port configured on NameNode. If there are multiple auxiliary ports, an arbitrary one is returned. If there is no auxiliary listener, returns null.
    
    Returns:
    
    a string of format host:port that points to an auxiliary NameNode address, or null if there is no such address.
  - getServiceRpcAddress
```
public java.net.InetSocketAddress getServiceRpcAddress()
```
    Returns:
    
    NameNode service RPC address if configured, the NameNode RPC address otherwise
  - getHttpAddress
```
public java.net.InetSocketAddress getHttpAddress()
```
    Returns:
    
    NameNode HTTP address, used by the Web UI, image transfer, and HTTP-based file system clients like WebHDFS
  - getHttpsAddress
```
public java.net.InetSocketAddress getHttpsAddress()
```
    Returns:
    
    NameNode HTTPS address, used by the Web UI, image transfer, and HTTP-based file system clients like WebHDFS
  - joinHttpServer
```
@VisibleForTesting
public void joinHttpServer()
```
    NameNodeHttpServer, used by unit tests to ensure a full shutdown, so that no bind exception is thrown during restart.
  - checkAllowFormat
```
public static void checkAllowFormat(org.apache.hadoop.conf.Configuration conf)
                             throws java.io.IOException
```
    Throws:
    
    java.io.IOException
  - initializeSharedEdits
```
@VisibleForTesting
public static boolean initializeSharedEdits(org.apache.hadoop.conf.Configuration conf)
                                     throws java.io.IOException
```
    Throws:
    
    java.io.IOException
  - initializeSharedEdits
```
@VisibleForTesting
public static boolean initializeSharedEdits(org.apache.hadoop.conf.Configuration conf,
                                            boolean force)
                                     throws java.io.IOException
```
    Throws:
    
    java.io.IOException
  - doRollback
```
@VisibleForTesting
public static boolean doRollback(org.apache.hadoop.conf.Configuration conf,
                                 boolean isConfirmationNeeded)
                          throws java.io.IOException
```
    Throws:
    
    java.io.IOException
  - getStartupOption
```
public static HdfsServerConstants.StartupOption getStartupOption(org.apache.hadoop.conf.Configuration conf)
```
  - createNameNode
```
public static NameNode createNameNode(java.lang.String[] argv,
                                      org.apache.hadoop.conf.Configuration conf)
                               throws java.io.IOException
```
    Throws:
    
    java.io.IOException
  - initializeGenericKeys
```
public static void initializeGenericKeys(org.apache.hadoop.conf.Configuration conf,
                                         java.lang.String nameserviceId,
                                         java.lang.String namenodeId)
```
    In federation configuration is set for a set of namenode and secondary namenode/backup/checkpointer, which are grouped under a logical nameservice ID. The configuration keys specific to them have suffix set to configured nameserviceId. This method copies the value from specific key of format key.nameserviceId to key, to set up the generic configuration. Once this is done, only generic version of the configuration is read in rest of the code, for backward compatibility and simpler code changes.
    
    Parameters:
    
    conf - Configuration object to lookup specific key and to set the value to the key passed. Note the conf object is modified
    
    nameserviceId - name service Id (to distinguish federated NNs)
    
    namenodeId - the namenode ID (to distinguish HA NNs)
    
    See Also:
    
    DFSUtil.setGenericConf(Configuration, String, String, String...)
  - getNameServiceId
```
protected java.lang.String getNameServiceId(org.apache.hadoop.conf.Configuration conf)
```
    Get the name service Id for the node
    
    Returns:
    
    name service Id or null if federation is not configured
  - main
```
public static void main(java.lang.String[] argv)
                 throws java.lang.Exception
```
    Throws:
    
    java.lang.Exception
  - getNameNodeState
```
@Metric({"NameNodeState","Namenode HA service state"})
public int getNameNodeState()
```
    Emit Namenode HA service state as an integer so that one can monitor NN HA state based on this metric.
    
    Returns:
    
    0 when not fully started 1 for active or standalone (non-HA) NN 2 for standby 3 for observer These are the same integer values for the HAServiceState enum.
  - getNNRole
```
public java.lang.String getNNRole()
```
    Description copied from interface: NameNodeStatusMXBean
    
    Gets the NameNode role.
    
    Specified by:
    
    getNNRole in interface NameNodeStatusMXBean
    
    Returns:
    
    the NameNode role.
  - getState
```
public java.lang.String getState()
```
    Description copied from interface: NameNodeStatusMXBean
    
    Gets the NameNode state.
    
    Specified by:
    
    getState in interface NameNodeStatusMXBean
    
    Returns:
    
    the NameNode state.
  - getHostAndPort
```
public java.lang.String getHostAndPort()
```
    Description copied from interface: NameNodeStatusMXBean
    
    Gets the host and port colon separated.
    
    Specified by:
    
    getHostAndPort in interface NameNodeStatusMXBean
    
    Returns:
    
    host and port colon separated.
  - isSecurityEnabled
```
public boolean isSecurityEnabled()
```
    Description copied from interface: NameNodeStatusMXBean
    
    Gets if security is enabled.
    
    Specified by:
    
    isSecurityEnabled in interface NameNodeStatusMXBean
    
    Returns:
    
    true, if security is enabled.
  - getLastHATransitionTime
```
public long getLastHATransitionTime()
```
    Description copied from interface: NameNodeStatusMXBean
    
    Gets the most recent HA transition time in milliseconds from the epoch.
    
    Specified by:
    
    getLastHATransitionTime in interface NameNodeStatusMXBean
    
    Returns:
    
    the most recent HA transition time in milliseconds from the epoch.
  - getBytesWithFutureGenerationStamps
```
public long getBytesWithFutureGenerationStamps()
```
    Description copied from interface: NameNodeStatusMXBean
    
    Gets number of bytes in blocks with future generation stamps.
    
    Specified by:
    
    getBytesWithFutureGenerationStamps in interface NameNodeStatusMXBean
    
    Returns:
    
    number of bytes that can be deleted if exited from safe mode.
  - getSlowPeersReport
```
public java.lang.String getSlowPeersReport()
```
    Description copied from interface: NameNodeStatusMXBean
    
    Retrieves information about slow DataNodes, if the feature is enabled. The report is in a JSON format.
    
    Specified by:
    
    getSlowPeersReport in interface NameNodeStatusMXBean
  - getSlowDisksReport
```
public java.lang.String getSlowDisksReport()
```
    Description copied from interface: NameNodeStatusMXBean
    
    Gets the topN slow disks in the cluster, if the feature is enabled.
    
    Specified by:
    
    getSlowDisksReport in interface NameNodeStatusMXBean
    
    Returns:
    
    JSON string of list of diskIDs and latencies
  - doImmediateShutdown
```
protected void doImmediateShutdown(java.lang.Throwable t)
                            throws org.apache.hadoop.util.ExitUtil.ExitException
```
    Shutdown the NN immediately in an ungraceful way. Used when it would be unsafe for the NN to continue operating, e.g. during a failed HA state transition.
    
    Parameters:
    
    t - exception which warrants the shutdown. Printed to the NN log before exit.
    
    Throws:
    
    org.apache.hadoop.util.ExitUtil.ExitException - thrown only for testing.
  - isStandbyState
```
public boolean isStandbyState()
```
  - isActiveState
```
public boolean isActiveState()
```
  - isObserverState
```
public boolean isObserverState()
```
  - getReconfigurableProperties
```
public java.util.Collection<java.lang.String> getReconfigurableProperties()
```
    Specified by:
    
    getReconfigurableProperties in interface org.apache.hadoop.conf.Reconfigurable
    
    Specified by:
    
    getReconfigurableProperties in class org.apache.hadoop.conf.ReconfigurableBase
  - reconfigurePropertyImpl
```
protected java.lang.String reconfigurePropertyImpl(java.lang.String property,
                                                   java.lang.String newVal)
                                            throws org.apache.hadoop.conf.ReconfigurationException
```
    Specified by:
    
    reconfigurePropertyImpl in class org.apache.hadoop.conf.ReconfigurableBase
    
    Throws:
    
    org.apache.hadoop.conf.ReconfigurationException
  - getNewConf
```
protected org.apache.hadoop.conf.Configuration getNewConf()
```
    Specified by:
    
    getNewConf in class org.apache.hadoop.conf.ReconfigurableBase

Class NameNode

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

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

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

Methods inherited from class java.lang.Object

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

Field Detail

NAMENODE_SPECIFIC_KEYS

NAMESERVICE_SPECIFIC_KEYS

DEFAULT_PORT

LOG

stateChangeLog

blockStateChangeLog

ACTIVE_STATE

STANDBY_STATE

OBSERVER_STATE

METRICS_LOG_NAME

namesystem

role

allowStaleStandbyReads

httpServer

stopRequested

nodeRegistration

tracer

Constructor Detail

NameNode

NameNode

Method Detail

getProtocolVersion

format

getNamesystem

getRpcServer

getHttpServer

queueExternalCall

initMetrics

getNameNodeMetrics

parseSpecialValue

getClientMachine

getClientIdAndCallId

getStartupProgress

getTokenServiceName

getClientNamenodeAddress

setServiceAddress

getServiceAddress

getRole

composeNotStartedMessage

getServiceRpcServerAddress

getRpcServerAddress

getServiceRpcServerBindHost

getRpcServerBindHost

setRpcServiceServerAddress

setRpcServerAddress

getHttpServerAddress

getHttpServerBindAddress

getHttpAddress

loadNamesystem

getRemoteUser

verifyToken

initialize

getAliasMapServer

startMetricsLogger

stopMetricsLogger

createRpcServer

createHAState

createHAContext

join

stop

isInSafeMode

getFSImage

getNameNodeAddress

getAuxiliaryNameNodeAddresses

getNameNodeAddressHostPortString

getNNAuxiliaryRpcAddress

getServiceRpcAddress

getHttpAddress

getHttpsAddress

joinHttpServer