Package org.apache.hadoop.ipc

Class Client

java.lang.Object

org.apache.hadoop.ipc.Client

All Implemented Interfaces:

java.lang.AutoCloseable

@Public
@Evolving
public class Client
extends java.lang.Object
implements java.lang.AutoCloseable

A client for an IPC service. IPC calls take a single Writable as a parameter, and return a Writable as their value. A service runs on a port and is defined by a parameter class and a value class.

See Also:

Server

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Client.ConnectionId	This class holds the address and the user ticket.
static class	Client.IpcStreams	Manages the input and output streams for an IPC connection.

Field Summary

Fields

Modifier and Type	Field	Description
static org.slf4j.Logger	LOG

Constructor Summary

Constructors

Constructor	Description
Client(java.lang.Class<? extends Writable> valueClass, Configuration conf)	Construct an IPC client with the default SocketFactory.
Client(java.lang.Class<? extends Writable> valueClass, Configuration conf, javax.net.SocketFactory factory)	Construct an IPC client whose values are of the given Writable class.

Method Summary

Modifier and Type	Method	Description
Writable	call(RPC.RpcKind rpcKind, Writable rpcRequest, Client.ConnectionId remoteId, java.util.concurrent.atomic.AtomicBoolean fallbackToSimpleAuth)	Make a call, passing rpcRequest, to the IPC server defined by remoteId, returning the rpc respond.
Writable	call(RPC.RpcKind rpcKind, Writable rpcRequest, Client.ConnectionId remoteId, java.util.concurrent.atomic.AtomicBoolean fallbackToSimpleAuth, AlignmentContext alignmentContext)
void	close()
static <T extends Writable> AsyncGet<T,java.io.IOException>	getAsyncRpcResponse()
static int	getCallId()
static java.lang.Object	getExternalHandler()
static int	getPingInterval(Configuration conf)	Get the ping interval from configuration; If not set in the configuration, return the default value.
static int	getRetryCount()
static int	getRpcTimeout(Configuration conf)	The time after which a RPC will timeout.
static int	getTimeout(Configuration conf)	Deprecated. use getRpcTimeout(Configuration) instead
static boolean	isAsynchronousMode()	Check if RPC is in asynchronous mode or not.
static int	nextCallId()	Returns the next valid sequential call ID by incrementing an atomic counter and masking off the sign bit.
static void	setAsynchronousMode(boolean async)	Set RPC to asynchronous or synchronous mode.
static void	setCallIdAndRetryCount(int cid, int rc, java.lang.Object externalHandler)	Set call id and retry count for the next call.
static void	setCallIdAndRetryCountUnprotected(java.lang.Integer cid, int rc, java.lang.Object externalHandler)
static void	setConnectTimeout(Configuration conf, int timeout)	set the connection timeout value in configuration
static void	setPingInterval(Configuration conf, int pingInterval)	set the ping interval value in configuration
void	stop()	Stop all threads related to this client.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

LOG

public static final org.slf4j.Logger LOG

Constructor Detail

Client

public Client(java.lang.Class<? extends Writable> valueClass,
              Configuration conf,
              javax.net.SocketFactory factory)

Construct an IPC client whose values are of the given Writable class.

Parameters:

valueClass - input valueClass.

conf - input configuration.

factory - input factory.

Client

public Client(java.lang.Class<? extends Writable> valueClass,
              Configuration conf)

Construct an IPC client with the default SocketFactory.

Parameters:

valueClass - input valueClass.

conf - input Configuration.

Method Detail

getAsyncRpcResponse

@Unstable
public static <T extends Writable> AsyncGet<T,java.io.IOException> getAsyncRpcResponse()

setCallIdAndRetryCount

public static void setCallIdAndRetryCount(int cid,
                                          int rc,
                                          java.lang.Object externalHandler)

Set call id and retry count for the next call.

Parameters:

cid - input cid.

rc - input rc.

externalHandler - input externalHandler.

setCallIdAndRetryCountUnprotected

public static void setCallIdAndRetryCountUnprotected(java.lang.Integer cid,
                                                     int rc,
                                                     java.lang.Object externalHandler)

getCallId

public static int getCallId()

getRetryCount

public static int getRetryCount()

getExternalHandler

public static java.lang.Object getExternalHandler()

setPingInterval

public static final void setPingInterval(Configuration conf,
                                         int pingInterval)

set the ping interval value in configuration

Parameters:

conf - Configuration

pingInterval - the ping interval

getPingInterval

public static final int getPingInterval(Configuration conf)

Get the ping interval from configuration; If not set in the configuration, return the default value.

Parameters:

conf - Configuration

Returns:

the ping interval

getTimeout

@Deprecated
public static final int getTimeout(Configuration conf)

Deprecated.

use getRpcTimeout(Configuration) instead

The time after which a RPC will timeout. If ping is not enabled (via ipc.client.ping), then the timeout value is the same as the pingInterval. If ping is enabled, then there is no timeout value.

Parameters:

conf - Configuration

Returns:

the timeout period in milliseconds. -1 if no timeout value is set

getRpcTimeout

public static final int getRpcTimeout(Configuration conf)

The time after which a RPC will timeout.

Parameters:

conf - Configuration

Returns:

the timeout period in milliseconds.

setConnectTimeout

public static final void setConnectTimeout(Configuration conf,
                                           int timeout)

set the connection timeout value in configuration

Parameters:

conf - Configuration

timeout - the socket connect timeout value

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

stop

public void stop()

Stop all threads related to this client. No further calls may be made using this client.

call

public Writable call(RPC.RpcKind rpcKind,
                     Writable rpcRequest,
                     Client.ConnectionId remoteId,
                     java.util.concurrent.atomic.AtomicBoolean fallbackToSimpleAuth)
              throws java.io.IOException

Make a call, passing rpcRequest, to the IPC server defined by remoteId, returning the rpc respond.

Parameters:

rpcKind - - input rpcKind.

rpcRequest - - contains serialized method and method parameters

remoteId - - the target rpc server

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

Returns:

the rpc response Throws exceptions if there are network problems or if the remote code threw an exception.

Throws:

java.io.IOException - raised on errors performing I/O.

call

public Writable call(RPC.RpcKind rpcKind,
                     Writable rpcRequest,
                     Client.ConnectionId remoteId,
                     java.util.concurrent.atomic.AtomicBoolean fallbackToSimpleAuth,
                     AlignmentContext alignmentContext)
              throws java.io.IOException

Throws:

java.io.IOException

isAsynchronousMode

@Unstable
public static boolean isAsynchronousMode()

Check if RPC is in asynchronous mode or not.

Returns:

true, if RPC is in asynchronous mode, otherwise false for synchronous mode.

setAsynchronousMode

@Unstable
public static void setAsynchronousMode(boolean async)

Set RPC to asynchronous or synchronous mode.

Parameters:

async - true, RPC will be in asynchronous mode, otherwise false for synchronous mode

nextCallId

public static int nextCallId()

Returns the next valid sequential call ID by incrementing an atomic counter and masking off the sign bit. Valid call IDs are non-negative integers in the range [ 0, 2^31 - 1 ]. Negative numbers are reserved for special purposes. The values can overflow back to 0 and be reused. Note that prior versions of the client did not mask off the sign bit, so a server may still see a negative call ID if it receives connections from an old client.

Returns:

next call ID

close

@Unstable
public void close()
           throws java.lang.Exception

Specified by:

close in interface java.lang.AutoCloseable

Throws:

java.lang.Exception