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.

Author:

Bela Ban

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	UDP.PacketReceiver

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

TP.Bundler, TP.ProtocolAdapter

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	disable_loopback
protected boolean	ip_mcast
protected int	ip_ttl
protected IpAddress	mcast_addr The multicast address (mcast address and port) this member uses
protected InetAddress	mcast_group_addr
protected int	mcast_port
protected UDP.PacketReceiver	mcast_receiver Runnable to receive multicast packets
protected int	mcast_recv_buf_size
protected int	mcast_send_buf_size
protected MulticastSocket	mcast_sock IP multicast socket for receiving multicast packets
protected DatagramSocket	sock Socket used for sending unicast and multicast packets and receiving unicast packets The address of this socket will be our local address (local_addr)
protected int	tos Traffic class for sending unicast and multicast datagrams.
protected UDP.PacketReceiver	ucast_receiver Runnable to receive unicast packets
protected int	ucast_recv_buf_size
protected int	ucast_send_buf_size

Fields inherited from class org.jgroups.protocols.TP

bind_addr, bind_interface_str, bind_port, bundler, bundler_capacity, bundler_type, can_bind_to_mcast_addr, channel_name, connect_count, connectLock, default_thread_factory, diag_handler, diagnostics_addr, diagnostics_port, discard_incompatible_packets, enable_bundling, enable_diagnostics, enable_unicast_bundling, external_addr, external_port, f, global_thread_factory, header, last_discovery_request, LIST, local_addr, log_discard_msgs, logical_addr_cache, logical_addr_cache_expiration, logical_addr_cache_max_size, loopback, max_bundle_size, max_bundle_timeout, members, MULTICAST, num_bytes_received, num_bytes_sent, num_incoming_msgs_received, num_msgs_received, num_msgs_sent, num_oob_msgs_received, OOB, 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, preregistered_probe_handlers, print_function, 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, tick_time, timer, timer_keep_alive_time, timer_max_threads, timer_min_threads, timer_queue_max_size, timer_rejection_policy, timer_thread_factory, timer_type, up_prots, wheel_size, who_has_cache

Fields inherited from class org.jgroups.stack.Protocol

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

Constructor Summary

Constructors

Constructor and Description
UDP()

Method Summary

Methods

Modifier and Type	Method and Description
protected void	_send(InetAddress dest, int port, boolean mcast, byte[] data, int offset, int length)
protected void	bindToInterfaces(List<NetworkInterface> interfaces, MulticastSocket s, InetAddress mcastAddr)
protected void	closeUnicastSocket()
protected DatagramSocket	createDatagramSocketWithBindPort() Creates a DatagramSocket when bind_port > 0.
protected DatagramSocket	createEphemeralDatagramSocket() Creates a DatagramSocket with a random port.
protected IpAddress	createLocalAddress()
protected void	createSockets() Create UDP sender and receiver sockets.
void	destroy() This method is called on a Channel.close().
protected void	destroySockets()
protected String	dumpSocketInfo()
String	getInfo()
InetAddress	getMulticastAddress()
int	getMulticastPort()
int	getMulticastTTL() Getter for current multicast TTL
protected PhysicalAddress	getPhysicalAddress()
protected void	handleConfigEvent(Map<String,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.
protected void	setBufferSize(DatagramSocket sock, int send_buf_size, int recv_buf_size)
void	setMaxBundleSize(int size)
void	setMcastPort(int mcast_port)
void	setMulticastAddress(InetAddress addr)
void	setMulticastPort(int mcast_port)
void	setMulticastTTL(int ttl) Set the ttl for multicast socket
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() Usually, src addresses are nulled, and the receiver simply sets them to the address of the sender.

Methods inherited from class org.jgroups.protocols.TP

addPhysicalAddressToCache, clearLogicalAddressCache, createThreadPool, dispatchToThreadPool, doSend, down, dumpTimerTasks, evictLogicalAddressCache, fetchLocalAddresses, getBindAddress, getBindPort, getBundlerBufferSize, getDefaultThreadPool, getDefaultThreadPoolThreadFactory, getLogDiscardMessages, getMaxBundleSize, getMaxBundleTimeout, getNumBytesReceived, getNumBytesSent, getNumMessagesReceived, getNumMessagesSent, getNumThreads, getNumTimerTasks, getOOBMaxQueueSize, getOOBMessages, getOOBPoolSize, getOOBQueueSize, getOOBThreadPool, getOOBThreadPoolKeepAliveTime, getOOBThreadPoolMaxThreads, getOOBThreadPoolMinThreads, getOOBThreadPoolThreadFactory, getPhysicalAddressFromCache, getPoolThreadGroup, getPortRange, getReceiveInterfaces, getRegularMaxQueueSize, getRegularMessages, getRegularPoolSize, getRegularQueueSize, getSingletonName, getSocketFactory, getThreadFactory, getThreadNamingPattern, getThreadPoolKeepAliveTime, getThreadPoolMaxThreads, getThreadPoolMinThreads, getTimer, getTimerClass, getTimerKeepAliveTime, getTimerMaxThreads, getTimerMinThreads, getTimerQueueSize, getTimerThreadFactory, getTimerThreads, getUpProtocols, handleDownEvent, init, isDefaulThreadPoolEnabled, isDiscardIncompatiblePackets, isEnableBundling, isEnableUnicastBundling, isLoopback, isMulticastCapable, isOOBThreadPoolEnabled, isReceiveOnAllInterfaces, isSingleton, passMessageUp, passToAllUpProtocols, printLogicalAddressCache, readMessage, readMessageList, receive, registerLocalAddress, registerProbeHandler, removeLogicalAddressFromCache, resetStats, send, sendToAllPhysicalAddresses, sendToSingleMember, setBindAddress, setBindPort, setBindToAllInterfaces, setDefaultThreadPool, setDefaultThreadPoolThreadFactory, setDiagnosticsHandler, setDiscardIncompatiblePackets, setEnableBundling, setEnableUnicastBundling, setInAllThreadFactories, setLogDiscardMessages, setLoopback, setMaxBundleTimeout, setOOBRejectionPolicy, setOOBThreadPool, setOOBThreadPoolKeepAliveTime, setOOBThreadPoolMaxThreads, setOOBThreadPoolMinThreads, setOOBThreadPoolThreadFactory, setPortRange, setRegularRejectionPolicy, setSocketFactory, setSourceAddress, setThreadFactory, setThreadNames, setThreadPoolKeepAliveTime, setThreadPoolMaxThreads, setThreadPoolMinThreads, setThreadPoolQueueEnabled, setTimer, setTimerKeepAliveTime, setTimerMaxThreads, setTimerMinThreads, setTimerThreadFactory, shutdownThreadPool, toString, unregisterProbeHandler, unsetThreadNames, up, writeMessage, writeMessageList

Methods inherited from class org.jgroups.stack.Protocol

dumpStats, enableStats, getConfigurableObjects, getDownProtocol, getId, getLevel, getName, getProtocolStack, getTransport, getUpProtocol, getValue, isErgonomics, printStats, providedDownServices, providedUpServices, requiredDownServices, requiredUpServices, resetStatistics, setDownProtocol, setErgonomics, setId, setLevel, setProtocolStack, setUpProtocol, setValue, setValues, statsEnabled

Methods inherited from class java.lang.Object

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

Field Detail

tos

protected int tos

Traffic class for sending unicast and multicast datagrams. Valid values are (check DatagramSocket.setTrafficClass(int) ); for details):

• IPTOS_LOWCOST (0x02), decimal 2
• IPTOS_RELIABILITY (0x04)<, decimal 4/LI>
• IPTOS_THROUGHPUT (0x08), decimal 8
• IPTOS_LOWDELAY (0x10), decimal 16

mcast_group_addr

protected InetAddress mcast_group_addr

mcast_port

protected int mcast_port

ip_mcast

protected boolean ip_mcast

ip_ttl

protected int ip_ttl

mcast_send_buf_size

protected int mcast_send_buf_size

mcast_recv_buf_size

protected int mcast_recv_buf_size

ucast_send_buf_size

protected int ucast_send_buf_size

ucast_recv_buf_size

protected int ucast_recv_buf_size

disable_loopback

protected boolean disable_loopback

mcast_addr

protected IpAddress mcast_addr

The multicast address (mcast address and port) this member uses

sock

protected DatagramSocket sock

Socket used for

1. sending unicast and multicast packets and
2. receiving unicast packets

The address of this socket will be our local address (local_addr)

mcast_sock

protected MulticastSocket mcast_sock

IP multicast socket for receiving multicast packets

mcast_receiver

protected UDP.PacketReceiver mcast_receiver

Runnable to receive multicast packets

ucast_receiver

protected UDP.PacketReceiver ucast_receiver

Runnable to receive unicast packets

Constructor Detail

UDP

public UDP()

Method Detail

supportsMulticasting

public boolean supportsMulticasting()

Usually, src addresses are nulled, and the receiver simply sets them to the address of the sender. However, for multiple addresses on a Windows loopback device, this doesn't work (see http://jira.jboss.com/jira/browse/JGRP-79 and the JGroups wiki for details). This must be the same value for all members of the same group. Default is true, for performance reasons

Specified by:

supportsMulticasting in class TP

setMulticastAddress

public void setMulticastAddress(InetAddress addr)

getMulticastAddress

public InetAddress getMulticastAddress()

getMulticastPort

public int getMulticastPort()

setMulticastPort

public void setMulticastPort(int mcast_port)

setMcastPort

public void setMcastPort(int mcast_port)

setMulticastTTL

public void setMulticastTTL(int ttl)
                     throws IOException

Set the ttl for multicast socket

Parameters:

ttl - the time to live for the socket.

Throws:

IOException

getMulticastTTL

public int getMulticastTTL()

Getter for current multicast TTL

Returns:

setMaxBundleSize

public void setMaxBundleSize(int size)

Overrides:

setMaxBundleSize in class TP

getInfo

public String getInfo()

Specified by:

getInfo in class TP

sendMulticast

public void sendMulticast(byte[] data,
                 int offset,
                 int length)
                   throws 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:

Exception

sendUnicast

public void sendUnicast(PhysicalAddress dest,
               byte[] data,
               int offset,
               int length)
                 throws 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:

Exception

_send

protected void _send(InetAddress dest,
         int port,
         boolean mcast,
         byte[] data,
         int offset,
         int length)
              throws Exception

Throws:

Exception

start

public void start()
           throws Exception

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

Overrides:

start in class TP

Throws:

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 Exception

Overrides:

handleConnect in class TP

Throws:

Exception

handleDisconnect

protected void handleDisconnect()

Overrides:

handleDisconnect in class TP

createSockets

protected void createSockets()
                      throws Exception

Create UDP sender and receiver sockets. Currently there are 2 sockets (sending and receiving). This is due to Linux's non-BSD compatibility in the JDK port (see DESIGN).

Throws:

Exception

destroySockets

protected void destroySockets()

createLocalAddress

protected IpAddress createLocalAddress()

getPhysicalAddress

protected PhysicalAddress getPhysicalAddress()

Specified by:

getPhysicalAddress in class TP

bindToInterfaces

protected void bindToInterfaces(List<NetworkInterface> interfaces,
                    MulticastSocket s,
                    InetAddress mcastAddr)

Parameters:

interfaces - List. Guaranteed to have no duplicates

s -

mcastAddr -

Throws:

IOException

createEphemeralDatagramSocket

protected DatagramSocket createEphemeralDatagramSocket()
                                                throws 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:

SocketException

createDatagramSocketWithBindPort

protected DatagramSocket createDatagramSocketWithBindPort()
                                                   throws 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:

Exception

dumpSocketInfo

protected String dumpSocketInfo()
                         throws Exception

Throws:

Exception

setBufferSize

protected void setBufferSize(DatagramSocket sock,
                 int send_buf_size,
                 int recv_buf_size)

closeUnicastSocket

protected void closeUnicastSocket()

handleConfigEvent

protected void handleConfigEvent(Map<String,Object> map)