Package org.apache.hadoop.hdfs

Class NameNodeProxies

java.lang.Object

org.apache.hadoop.hdfs.NameNodeProxies

@Private
public class NameNodeProxies
extends java.lang.Object

Create proxy objects to communicate with a remote NN. All remote access to an NN should be funneled through this class. Most of the time you'll want to use createProxy(Configuration, URI, Class), which will create either an HA- or non-HA-enabled client proxy as appropriate.

Constructor Summary

Constructors

Constructor	Description
NameNodeProxies()

Method Summary

Modifier and Type	Method	Description
static <T> org.apache.hadoop.hdfs.NameNodeProxiesClient.ProxyAndInfo<T>	createNonHAProxy(org.apache.hadoop.conf.Configuration conf, java.net.InetSocketAddress nnAddr, java.lang.Class<T> xface, org.apache.hadoop.security.UserGroupInformation ugi, boolean withRetries)	Creates an explicitly non-HA-enabled proxy object.
static <T> org.apache.hadoop.hdfs.NameNodeProxiesClient.ProxyAndInfo<T>	createNonHAProxy(org.apache.hadoop.conf.Configuration conf, java.net.InetSocketAddress nnAddr, java.lang.Class<T> xface, org.apache.hadoop.security.UserGroupInformation ugi, boolean withRetries, java.util.concurrent.atomic.AtomicBoolean fallbackToSimpleAuth, org.apache.hadoop.ipc.AlignmentContext alignmentContext)	Creates an explicitly non-HA-enabled proxy object.
static <T> org.apache.hadoop.hdfs.NameNodeProxiesClient.ProxyAndInfo<T>	createProxy(org.apache.hadoop.conf.Configuration conf, java.net.URI nameNodeUri, java.lang.Class<T> xface)	Creates the namenode proxy with the passed protocol.
static <T> org.apache.hadoop.hdfs.NameNodeProxiesClient.ProxyAndInfo<T>	createProxy(org.apache.hadoop.conf.Configuration conf, java.net.URI nameNodeUri, java.lang.Class<T> xface, java.util.concurrent.atomic.AtomicBoolean fallbackToSimpleAuth)	Creates the namenode proxy with the passed protocol.

Methods inherited from class java.lang.Object

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

Constructor Detail

NameNodeProxies

public NameNodeProxies()

Method Detail

createProxy

public static <T> org.apache.hadoop.hdfs.NameNodeProxiesClient.ProxyAndInfo<T> createProxy(org.apache.hadoop.conf.Configuration conf,
                                                                                           java.net.URI nameNodeUri,
                                                                                           java.lang.Class<T> xface)
                                                                                    throws java.io.IOException

Creates the namenode proxy with the passed protocol. This will handle creation of either HA- or non-HA-enabled proxy objects, depending upon if the provided URI is a configured logical URI.

Parameters:

conf - the configuration containing the required IPC properties, client failover configurations, etc.

nameNodeUri - the URI pointing either to a specific NameNode or to a logical nameservice.

xface - the IPC interface which should be created

Returns:

an object containing both the proxy and the associated delegation token service it corresponds to

Throws:

java.io.IOException - if there is an error creating the proxy

createProxy

public static <T> org.apache.hadoop.hdfs.NameNodeProxiesClient.ProxyAndInfo<T> createProxy(org.apache.hadoop.conf.Configuration conf,
                                                                                           java.net.URI nameNodeUri,
                                                                                           java.lang.Class<T> xface,
                                                                                           java.util.concurrent.atomic.AtomicBoolean fallbackToSimpleAuth)
                                                                                    throws java.io.IOException

Creates the namenode proxy with the passed protocol. This will handle creation of either HA- or non-HA-enabled proxy objects, depending upon if the provided URI is a configured logical URI.

Parameters:

conf - the configuration containing the required IPC properties, client failover configurations, etc.

nameNodeUri - the URI pointing either to a specific NameNode or to a logical nameservice.

xface - the IPC interface which should be created

fallbackToSimpleAuth - set to true or false during calls to indicate if a secure client falls back to simple auth

Returns:

an object containing both the proxy and the associated delegation token service it corresponds to

Throws:

java.io.IOException - if there is an error creating the proxy

createNonHAProxy

public static <T> org.apache.hadoop.hdfs.NameNodeProxiesClient.ProxyAndInfo<T> createNonHAProxy(org.apache.hadoop.conf.Configuration conf,
                                                                                                java.net.InetSocketAddress nnAddr,
                                                                                                java.lang.Class<T> xface,
                                                                                                org.apache.hadoop.security.UserGroupInformation ugi,
                                                                                                boolean withRetries)
                                                                                         throws java.io.IOException

Creates an explicitly non-HA-enabled proxy object. Most of the time you don't want to use this, and should instead use createProxy(org.apache.hadoop.conf.Configuration, java.net.URI, java.lang.Class<T>).

Parameters:

conf - the configuration object

nnAddr - address of the remote NN to connect to

xface - the IPC interface which should be created

ugi - the user who is making the calls on the proxy object

withRetries - certain interfaces have a non-standard retry policy

Returns:

an object containing both the proxy and the associated delegation token service it corresponds to

Throws:

java.io.IOException

createNonHAProxy

public static <T> org.apache.hadoop.hdfs.NameNodeProxiesClient.ProxyAndInfo<T> createNonHAProxy(org.apache.hadoop.conf.Configuration conf,
                                                                                                java.net.InetSocketAddress nnAddr,
                                                                                                java.lang.Class<T> xface,
                                                                                                org.apache.hadoop.security.UserGroupInformation ugi,
                                                                                                boolean withRetries,
                                                                                                java.util.concurrent.atomic.AtomicBoolean fallbackToSimpleAuth,
                                                                                                org.apache.hadoop.ipc.AlignmentContext alignmentContext)
                                                                                         throws java.io.IOException

Creates an explicitly non-HA-enabled proxy object. Most of the time you don't want to use this, and should instead use createProxy(org.apache.hadoop.conf.Configuration, java.net.URI, java.lang.Class<T>).

Parameters:

conf - the configuration object

nnAddr - address of the remote NN to connect to

xface - the IPC interface which should be created

ugi - the user who is making the calls on the proxy object

withRetries - certain interfaces have a non-standard retry policy

fallbackToSimpleAuth - - set to true or false during this method to indicate if a secure client falls back to simple auth

Returns:

an object containing both the proxy and the associated delegation token service it corresponds to

Throws:

java.io.IOException