org.jgroups.stack
Class GossipRouter

java.lang.Object
  org.jgroups.stack.GossipRouter

public class GossipRouter
extends java.lang.Object

Router for TCP based group comunication (using layer TCP instead of UDP). Instead of the TCP layer sending packets point-to-point to each other member, it sends the packet to the router which - depending on the target address - multicasts or unicasts it to the group / or single member.

This class is especially interesting for applets which cannot directly make connections (neither UDP nor TCP) to a host different from the one they were loaded from. Therefore, an applet would create a normal channel plus protocol stack, but the bottom layer would have to be the TCP layer which sends all packets point-to-point (over a TCP connection) to the router, which in turn forwards them to their end location(s) (also over TCP). A centralized router would therefore have to be running on the host the applet was loaded from.

An alternative for running JGroups in an applet (IP multicast is not allows in applets as of 1.2), is to use point-to-point UDP communication via the gossip server. However, then the appplet has to be signed which involves additional administrative effort on the part of the user.

Note that a GossipRouter is also a good way of running JGroups in Amazon's EC2 environment which (as of summer 09) doesn't support IP multicasting.

Since:

2.1.1

Author:

Bela Ban, Vladimir Blagojevic, Ovidiu Feodorov

Nested Class Summary

static interface

GossipRouter.ConnectionTearListener

Field Summary

static byte	CLOSE
static byte	CONNECT
static byte	CONNECT_OK
protected java.util.List<GossipRouter.ConnectionTearListener>	connectionTearListeners
protected ThreadFactory	default_thread_factory
static byte	DISCONNECT
static byte	DISCONNECT_OK
static byte	GOSSIP_GET
protected Log	log
static byte	MESSAGE
static byte	OP_FAIL
static byte	PING
static int	PORT
static byte	SUSPECT
protected java.util.Timer	timer

Constructor Summary

GossipRouter()

GossipRouter(int port)

GossipRouter(int port, java.lang.String bindAddressString)

GossipRouter(int port, java.lang.String bindAddressString, boolean jmx)

GossipRouter(int port, java.lang.String bindAddressString, boolean jmx, long expiryTime)

Method Summary

void	clear()
void	destroy()
java.lang.String	dumpAddresssMappings()
java.lang.String	dumpRoutingTable()
java.lang.String	dumpRoutingTableDetailed()
int	getBacklog()
java.lang.String	getBindAddress()
ThreadFactory	getDefaultThreadPoolThreadFactory()
long	getExpiryTime()
long	getLingerTimeout()
int	getPort()
long	getSocketReadTimeout()
boolean	isDiscardLoopbacks()
boolean	isRunning()
boolean	isStarted()
static void	main(java.lang.String[] args)
protected boolean	removeGroupIfEmpty(java.lang.String group)
void	setBacklog(int backlog)
void	setBindAddress(java.lang.String bindAddress)
void	setDiscardLoopbacks(boolean discard_loopbacks)
void	setExpiryTime(long expiryTime)
void	setLingerTimeout(long linger_timeout)
void	setPort(int port)
void	setSocketReadTimeout(long sock_read_timeout)
void	start() Lifecycle operation.
void	stop() Always called before destroy().
static java.lang.String	type2String(int type)

Methods inherited from class java.lang.Object

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

Field Detail

CONNECT

public static final byte CONNECT

See Also:

Constant Field Values

DISCONNECT

public static final byte DISCONNECT

See Also:

Constant Field Values

GOSSIP_GET

public static final byte GOSSIP_GET

See Also:

Constant Field Values

MESSAGE

public static final byte MESSAGE

See Also:

Constant Field Values

SUSPECT

public static final byte SUSPECT

See Also:

Constant Field Values

PING

public static final byte PING

See Also:

Constant Field Values

CLOSE

public static final byte CLOSE

See Also:

Constant Field Values

CONNECT_OK

public static final byte CONNECT_OK

See Also:

Constant Field Values

OP_FAIL

public static final byte OP_FAIL

See Also:

Constant Field Values

DISCONNECT_OK

public static final byte DISCONNECT_OK

See Also:

Constant Field Values

PORT

public static final int PORT

See Also:

Constant Field Values

connectionTearListeners

protected java.util.List<GossipRouter.ConnectionTearListener> connectionTearListeners

default_thread_factory

protected ThreadFactory default_thread_factory

timer

protected java.util.Timer timer

log

protected final Log log

Constructor Detail

GossipRouter

public GossipRouter()

GossipRouter

public GossipRouter(int port)

GossipRouter

public GossipRouter(int port,
                    java.lang.String bindAddressString)

GossipRouter

public GossipRouter(int port,
                    java.lang.String bindAddressString,
                    boolean jmx)

GossipRouter

public GossipRouter(int port,
                    java.lang.String bindAddressString,
                    boolean jmx,
                    long expiryTime)

Method Detail

setPort

public void setPort(int port)

getPort

public int getPort()

setBindAddress

public void setBindAddress(java.lang.String bindAddress)

getBindAddress

public java.lang.String getBindAddress()

getBacklog

public int getBacklog()

setBacklog

public void setBacklog(int backlog)

setExpiryTime

public void setExpiryTime(long expiryTime)

getExpiryTime

public long getExpiryTime()

isStarted

public boolean isStarted()

isDiscardLoopbacks

public boolean isDiscardLoopbacks()

setDiscardLoopbacks

public void setDiscardLoopbacks(boolean discard_loopbacks)

getLingerTimeout

public long getLingerTimeout()

setLingerTimeout

public void setLingerTimeout(long linger_timeout)

getSocketReadTimeout

public long getSocketReadTimeout()

setSocketReadTimeout

public void setSocketReadTimeout(long sock_read_timeout)

getDefaultThreadPoolThreadFactory

public ThreadFactory getDefaultThreadPoolThreadFactory()

type2String

public static java.lang.String type2String(int type)

start

public void start()
           throws java.lang.Exception

Lifecycle operation. Called after create(). When this method is called, the managed attributes have already been set.
Brings the Router into a fully functional state.

Throws:

java.lang.Exception

stop

public void stop()

Always called before destroy(). Close connections and frees resources.

clear

public void clear()

destroy

public void destroy()

isRunning

public boolean isRunning()

dumpRoutingTable

public java.lang.String dumpRoutingTable()

dumpRoutingTableDetailed

public java.lang.String dumpRoutingTableDetailed()

dumpAddresssMappings

public java.lang.String dumpAddresssMappings()

removeGroupIfEmpty

protected boolean removeGroupIfEmpty(java.lang.String group)

main

public static void main(java.lang.String[] args)
                 throws java.lang.Exception

Throws:

java.lang.Exception