org.jgroups.protocols
Class MPING

java.lang.Object
  org.jgroups.stack.Protocol
      org.jgroups.protocols.Discovery
          org.jgroups.protocols.PING
              org.jgroups.protocols.MPING

All Implemented Interfaces:

java.lang.Runnable

public class MPING
extends PING
implements java.lang.Runnable

Uses its own IP multicast socket to send and receive discovery requests/responses. Can be used in conjuntion with a non-UDP transport, e.g. TCP.

The discovery is assymetric: discovery requests are broadcast via the multicast socket, and received via the multicast socket by everyone in the group. However, the discovery responses are sent back via the regular transport (e.g. TCP) to the sender (discovery request contained sender's regular address, e.g. 192.168.0.2:7800).

Author:

Bela Ban

Nested Class Summary

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

Discovery.Responses

Field Summary

protected java.lang.String

bind_interface_str

Fields inherited from class org.jgroups.protocols.Discovery

break_on_coord_rsp, current_coord, force_sending_discovery_rsps, group_addr, is_coord, is_leaving, is_server, local_addr, members, num_discovery_requests, num_initial_members, num_initial_srv_members, ping_responses, return_entire_cache, stagger_timeout, timeout, timer, use_disk_cache, view

Fields inherited from class org.jgroups.stack.Protocol

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

Constructor Summary

MPING()

Method Summary

java.net.InetAddress	getBindAddr()
java.net.InetAddress	getMcastAddr()
int	getMcastPort()
java.util.List<java.net.NetworkInterface>	getReceiveInterfaces()
java.util.List<java.net.NetworkInterface>	getSendInterfaces()
int	getTTL()
void	init() Called after instance has been created (null constructor) and before protocol is started.
boolean	isReceiveOnAllInterfaces()
boolean	isSendOnAllInterfaces()
void	run()
protected void	sendMcastDiscoveryRequest(Message msg)
void	setBindAddr(java.net.InetAddress bind_addr)
void	setMcastAddr(java.net.InetAddress mcast_addr)
void	setMcastPort(int mcast_port)
void	setMulticastAddress(java.lang.String addr)
void	setTTL(int ip_ttl)
void	start() This method is called on a Channel.connect(String).
void	stop() This method is called on a Channel.disconnect().
java.lang.Object	up(Event evt) An event was received from the layer below.

Methods inherited from class org.jgroups.protocols.PING

fetchClusterMembers, isDynamic, sendDiscoveryRequestsInParallel

Methods inherited from class org.jgroups.protocols.Discovery

deserialize, discoveryRequestReceived, down, findAllViews, findAllViewsAsString, findInitialMembers, findInitialMembersAsString, findMembers, getCurrentCoord, getNumberOfDiscoveryRequestsSent, getNumInitialMembers, getTimeout, getView, getViewId, handleConnect, handleDisconnect, isMergeRunning, providedUpServices, resetStats, sendDiscoveryRequest, sendDiscoveryResponse, serializeWithoutView, setForceSendingDiscoveryRsps, setNumInitialMembers, setTimeout

Methods inherited from class org.jgroups.stack.Protocol

destroy, dumpStats, enableStats, getConfigurableObjects, getDownProtocol, getDownServices, getId, getIdsAbove, getLevel, getName, getProtocolStack, getSocketFactory, getThreadFactory, getTransport, getUpProtocol, getUpServices, getValue, isErgonomics, printStats, providedDownServices, requiredDownServices, requiredUpServices, resetStatistics, setDownProtocol, setErgonomics, setId, setLevel, setProtocolStack, setSocketFactory, setUpProtocol, setValue, setValues, statsEnabled

Methods inherited from class java.lang.Object

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

Field Detail

bind_interface_str

protected java.lang.String bind_interface_str

Constructor Detail

MPING

public MPING()

Method Detail

getBindAddr

public java.net.InetAddress getBindAddr()

setBindAddr

public void setBindAddr(java.net.InetAddress bind_addr)

getReceiveInterfaces

public java.util.List<java.net.NetworkInterface> getReceiveInterfaces()

getSendInterfaces

public java.util.List<java.net.NetworkInterface> getSendInterfaces()

isReceiveOnAllInterfaces

public boolean isReceiveOnAllInterfaces()

isSendOnAllInterfaces

public boolean isSendOnAllInterfaces()

getTTL

public int getTTL()

setTTL

public void setTTL(int ip_ttl)

getMcastAddr

public java.net.InetAddress getMcastAddr()

setMcastAddr

public void setMcastAddr(java.net.InetAddress mcast_addr)

setMulticastAddress

public void setMulticastAddress(java.lang.String addr)
                         throws java.net.UnknownHostException

Throws:

java.net.UnknownHostException

getMcastPort

public int getMcastPort()

setMcastPort

public void setMcastPort(int mcast_port)

up

public java.lang.Object up(Event evt)

Description copied from class: Discovery

An event was received from the layer below. Usually the current layer will want to examine the event type and - depending on its type - perform some computation (e.g. removing headers from a MSG event type, or updating the internal membership list when receiving a VIEW_CHANGE event). Finally the event is either a) discarded, or b) an event is sent down the stack using PassDown or c) the event (or another event) is sent up the stack using PassUp.

For the PING protocol, the Up operation does the following things. 1. If the event is a Event.MSG then PING will inspect the message header. If the header is null, PING simply passes up the event If the header is PingHeader.GET_MBRS_REQ then the PING protocol will PassDown a PingRequest message If the header is PingHeader.GET_MBRS_RSP we will add the message to the initial members vector and wake up any waiting threads. 2. If the event is Event.SET_LOCAL_ADDR we will simple set the local address of this protocol 3. For all other messages we simple pass it up to the protocol above

Overrides:

up in class Discovery

Parameters:

evt - - the event that has been sent from the layer below

init

public void init()
          throws java.lang.Exception

Description copied from class: Protocol

Called after instance has been created (null constructor) and before protocol is started. Properties are already set. Other protocols are not yet connected and events cannot yet be sent.

Overrides:

init in class Discovery

Throws:

java.lang.Exception - Thrown if protocol cannot be initialized successfully. This will cause the ProtocolStack to fail, so the channel constructor will throw an exception

start

public void start()
           throws java.lang.Exception

Description copied from class: Protocol

This method is called on a Channel.connect(String). Starts work. Protocols are connected and queues are ready to receive events. Will be called from bottom to top. This call will replace the START and START_OK events.

Overrides:

start in class Discovery

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 Discovery

sendMcastDiscoveryRequest

protected void sendMcastDiscoveryRequest(Message msg)

Overrides:

sendMcastDiscoveryRequest in class Discovery

run

public void run()

Specified by:

run in interface java.lang.Runnable