org.jgroups.protocols
Class UDP

java.lang.Object
  org.jgroups.stack.Protocol
      org.jgroups.protocols.TP
          org.jgroups.protocols.UDP

public class UDP
extends TP

IP multicast transport based on UDP. Messages to the group (msg.dest == null) will be multicast (to all group members), whereas point-to-point messages (msg.dest != null) will be unicast to a single member. Uses a multicast and a unicast socket.

The following properties are read by the UDP protocol:

• param mcast_addr - the multicast address to use; default is 228.8.8.8.
• param mcast_port - (int) the port that the multicast is sent on; default is 7600
• param ip_mcast - (boolean) flag whether to use IP multicast; default is true.
• param ip_ttl - the default time-to-live for multicast packets sent out on this socket; default is 32.
• param use_packet_handler - boolean, defaults to false. If set, the mcast and ucast receiver threads just put the datagram's payload (a byte buffer) into a queue, from where a separate thread will dequeue and handle them (unmarshal and pass up). This frees the receiver threads from having to do message unmarshalling; this time can now be spent receiving packets. If you have lots of retransmissions because of network input buffer overflow, consider setting this property to true.

Version:

$Id: UDP.java,v 1.215 2010/06/15 10:10:40 belaban Exp $

Author:

Bela Ban

Nested Class Summary

class

UDP.PacketReceiver

Nested classes/interfaces inherited from class org.jgroups.protocols.TP

TP.Bundler, TP.ProbeHandler, TP.ProtocolAdapter

Field Summary

Fields inherited from class org.jgroups.protocols.TP

bind_addr, bind_interface_str, bind_port, bundler_capacity, bundler_type, can_bind_to_mcast_addr, channel_name, connect_count, connectLock, default_thread_factory, diagnostics_addr, diagnostics_port, discard_incompatible_packets, enable_bundling, enable_diagnostics, enable_unicast_bundling, global_thread_factory, header, local_addr, logical_addr_cache, logical_addr_cache_expiration, logical_addr_cache_max_size, loopback, max_bundle_size, max_bundle_timeout, members, num_bytes_received, num_bytes_sent, num_incoming_msgs_received, num_msgs_received, num_msgs_sent, num_oob_msgs_received, num_timer_threads, oob_thread_factory, oob_thread_pool, oob_thread_pool_enabled, oob_thread_pool_keep_alive_time, oob_thread_pool_max_threads, oob_thread_pool_min_threads, oob_thread_pool_queue, oob_thread_pool_queue_enabled, oob_thread_pool_queue_max_size, pool_thread_group, port_range, receive_interfaces, receive_on_all_interfaces, singleton_name, socket_factory, thread_naming_pattern, thread_pool, thread_pool_enabled, thread_pool_keep_alive_time, thread_pool_max_threads, thread_pool_min_threads, thread_pool_queue, thread_pool_queue_enabled, thread_pool_queue_max_size, thread_pool_rejection_policy, timer, timer_thread_factory, up_prots, who_has_cache

Fields inherited from class org.jgroups.stack.Protocol

down_prot, id, log, name, stack, stats, up_prot

Constructor Summary

UDP()
Creates the UDP protocol, and initializes the state variables, does however not start any sockets or threads.

Method Summary

protected java.net.DatagramSocket	createDatagramSocketWithBindPort() Creates a DatagramSocket when bind_port > 0.
protected java.net.DatagramSocket	createEphemeralDatagramSocket() Creates a DatagramSocket with a random port.
protected IpAddress	createLocalAddress()
void	destroy() This method is called on a Channel.close().
protected void	destroySockets()
java.lang.String	getInfo()
java.net.InetAddress	getMulticastAddress()
int	getMulticastPort()
protected PhysicalAddress	getPhysicalAddress()
protected void	handleConfigEvent(java.util.Map<java.lang.String,java.lang.Object> map)
protected void	handleConnect()
protected void	handleDisconnect()
void	sendMulticast(byte[] data, int offset, int length) Send to all members in the group.
void	sendUnicast(PhysicalAddress dest, byte[] data, int offset, int length) Send a unicast to 1 member.
void	setMcastPort(int mcast_port)
void	setMulticastAddress(java.net.InetAddress addr)
void	setMulticastPort(int mcast_port)
void	start() Creates the unicast and multicast sockets and starts the unicast and multicast receiver threads
void	stop() This method is called on a Channel.disconnect().
boolean	supportsMulticasting() Whether or not hardware multicasting is supported

Methods inherited from class org.jgroups.protocols.TP

addPhysicalAddressToCache, clearLogicalAddressCache, createThreadPool, doSend, down, evictLogicalAddressCache, fetchLocalAddresses, getBindAddress, getBindAddressAsInetAddress, getBindPort, getBindToAllInterfaces, getBundlerBufferSize, getDefaultThreadPool, getDefaultThreadPoolThreadFactory, getLogDiscardMessages, getMaxBundleSize, getMaxBundleTimeout, getNumBytesReceived, getNumBytesSent, getNumMessagesReceived, getNumMessagesSent, getNumTimerTasks, getOOBMaxQueueSize, getOOBMessages, getOOBPoolSize, getOOBQueueSize, getOOBThreadPool, getOOBThreadPoolKeepAliveTime, getOOBThreadPoolMaxThreads, getOOBThreadPoolMinThreads, getOOBThreadPoolThreadFactory, getPhysicalAddressFromCache, getPoolThreadGroup, getPortRange, getReceiveInterfaces, getRegularMaxQueueSize, getRegularMessages, getRegularPoolSize, getRegularQueueSize, getSendInterfaces, getSingletonName, getSocketFactory, getThreadFactory, getThreadNamingPattern, getThreadPoolKeepAliveTime, getThreadPoolMaxThreads, getThreadPoolMinThreads, getTimer, getTimerThreadFactory, getUpProtocols, handleDownEvent, init, isDefaulThreadPoolEnabled, isDiscardIncompatiblePackets, isEnableBundling, isEnableUnicastBundling, isLoopback, isOOBThreadPoolEnabled, isReceiveOnAllInterfaces, isSendOnAllInterfaces, isSingleton, isUseIncomingPacketHandler, parseRejectionPolicy, passToAllUpProtocols, printLogicalAddressCache, readMessage, receive, registerLocalAddress, registerProbeHandler, removeLogicalAddressFromCache, resetStats, send, sendToAllPhysicalAddresses, sendToSingleMember, setBindAddress, setBindPort, setBindToAllInterfaces, setDefaultThreadPool, setDefaultThreadPoolThreadFactory, setDiscardIncompatiblePackets, setEnableBundling, setEnableUnicastBundling, setLogDiscardMessages, setLoopback, setMaxBundleSize, setMaxBundleTimeout, setOOBRejectionPolicy, setOOBThreadPool, setOOBThreadPoolKeepAliveTime, setOOBThreadPoolMaxThreads, setOOBThreadPoolMinThreads, setOOBThreadPoolThreadFactory, setPortRange, setRegularRejectionPolicy, setSocketFactory, setThreadFactory, setThreadNames, setThreadPoolKeepAliveTime, setThreadPoolMaxThreads, setThreadPoolMinThreads, setThreadPoolQueueEnabled, setTimerThreadFactory, setUseConcurrentStack, toString, unregisterProbeHandler, unsetThreadNames, up, writeMessage

Methods inherited from class org.jgroups.stack.Protocol

downThreadEnabled, dumpStats, enableStats, getConfigurableObjects, getDownProtocol, getId, getLevel, getName, getProperties, getProtocolStack, getTransport, getUpProtocol, printStats, providedDownServices, providedUpServices, requiredDownServices, requiredUpServices, setDownProtocol, setId, setLevel, setProperties, setPropertiesInternal, setProperty, setProtocolStack, setUpProtocol, statsEnabled, upThreadEnabled

Methods inherited from class java.lang.Object

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

Constructor Detail

UDP

public UDP()

Creates the UDP protocol, and initializes the state variables, does however not start any sockets or threads.

Method Detail

supportsMulticasting

public boolean supportsMulticasting()

Description copied from class: TP

Whether or not hardware multicasting is supported

Specified by:

supportsMulticasting in class TP

setMulticastAddress

public void setMulticastAddress(java.net.InetAddress addr)

getMulticastAddress

public java.net.InetAddress getMulticastAddress()

getMulticastPort

public int getMulticastPort()

setMulticastPort

public void setMulticastPort(int mcast_port)

setMcastPort

public void setMcastPort(int mcast_port)

getInfo

public java.lang.String getInfo()

Specified by:

getInfo in class TP

sendMulticast

public void sendMulticast(byte[] data,
                          int offset,
                          int length)
                   throws java.lang.Exception

Description copied from class: TP

Send to all members in the group. UDP would use an IP multicast message, whereas TCP would send N messages, one for each member

Specified by:

sendMulticast in class TP

Parameters:

data - The data to be sent. This is not a copy, so don't modify it

Throws:

java.lang.Exception

sendUnicast

public void sendUnicast(PhysicalAddress dest,
                        byte[] data,
                        int offset,
                        int length)
                 throws java.lang.Exception

Description copied from class: TP

Send a unicast to 1 member. Note that the destination address is a *physical*, not a logical address

Specified by:

sendUnicast in class TP

Parameters:

dest - Must be a non-null unicast address

data - The data to be sent. This is not a copy, so don't modify it

Throws:

java.lang.Exception

start

public void start()
           throws java.lang.Exception

Creates the unicast and multicast sockets and starts the unicast and multicast receiver threads

Overrides:

start in class TP

Throws:

java.lang.Exception - Thrown if protocol cannot be started successfully. This will cause the ProtocolStack to fail, so Channel.connect(String) will throw an exception

stop

public void stop()

Description copied from class: Protocol

This method is called on a Channel.disconnect(). Stops work (e.g. by closing multicast socket). Will be called from top to bottom. This means that at the time of the method invocation the neighbor protocol below is still working. This method will replace the STOP, STOP_OK, CLEANUP and CLEANUP_OK events. The ProtocolStack guarantees that when this method is called all messages in the down queue will have been flushed

Overrides:

stop in class TP

destroy

public void destroy()

Description copied from class: Protocol

This method is called on a Channel.close(). Does some cleanup; after the call the VM will terminate

Overrides:

destroy in class TP

handleConnect

protected void handleConnect()
                      throws java.lang.Exception

Overrides:

handleConnect in class TP

Throws:

java.lang.Exception

handleDisconnect

protected void handleDisconnect()

Overrides:

handleDisconnect in class TP

destroySockets

protected void destroySockets()

createLocalAddress

protected IpAddress createLocalAddress()

getPhysicalAddress

protected PhysicalAddress getPhysicalAddress()

Specified by:

getPhysicalAddress in class TP

createEphemeralDatagramSocket

protected java.net.DatagramSocket createEphemeralDatagramSocket()
                                                         throws java.net.SocketException

Creates a DatagramSocket with a random port. Because in certain operating systems, ports are reused, we keep a list of the n last used ports, and avoid port reuse

Throws:

java.net.SocketException

createDatagramSocketWithBindPort

protected java.net.DatagramSocket createDatagramSocketWithBindPort()
                                                            throws java.lang.Exception

Creates a DatagramSocket when bind_port > 0. Attempts to allocate the socket with port == bind_port, and increments until it finds a valid port, or until port_range has been exceeded

Returns:

DatagramSocket The newly created socket

Throws:

java.lang.Exception

handleConfigEvent

protected void handleConfigEvent(java.util.Map<java.lang.String,java.lang.Object> map)