org.jgroups.protocols
Class TCPGOSSIP

java.lang.Object
  org.jgroups.stack.Protocol
      org.jgroups.protocols.Discovery
          org.jgroups.protocols.TCPGOSSIP

public class TCPGOSSIP
extends Discovery

The TCPGOSSIP protocol layer retrieves the initial membership (used by the GMS when started by sending event FIND_INITIAL_MBRS down the stack). We do this by contacting one or more GossipRouters, which must be running at well-known addresses:ports. The responses should allow us to determine the coordinator whom we have to contact, e.g. in case we want to join the group. When we are a server (after having received the BECOME_SERVER event), we'll respond to TCPGOSSIP requests with a TCPGOSSIP response.

The FIND_INITIAL_MBRS event will eventually be answered with a FIND_INITIAL_MBRS_OK event up the stack.

Author:

Bela Ban

Field Summary

Fields inherited from class org.jgroups.stack.Protocol

down_handler, down_prot, down_queue, down_thread, down_thread_prio, log, observer, props, stack, stats, up_handler, up_prot, up_queue, up_thread, up_thread_prio

Constructor Summary

TCPGOSSIP()

Method Summary

void	destroy() This method is called on a Channel.close().
java.lang.String	getName()
void	handleConnectOK() Called when CONNECT_OK has been received
void	sendGetMembersRequest()
boolean	setProperties(java.util.Properties props) sets the properties of the PING protocol.
void	start() This method is called on a Channel.connect(String).
void	stop() This method is called on a Channel.disconnect().

Methods inherited from class org.jgroups.protocols.Discovery

down, findInitialMembers, findInitialMembersAsString, getNumberOfDiscoveryRequestsSent, getNumInitialMembers, getNumPingRequests, getTimeout, handleConnect, handleDisconnect, localAddressSet, makeView, providedUpServices, resetStats, setNumInitialMembers, setNumPingRequests, setTimeout, up

Methods inherited from class org.jgroups.stack.Protocol

downThreadEnabled, dumpStats, enableStats, getDownProtocol, getDownQueue, getProperties, getUpProtocol, getUpQueue, handleSpecialDownEvent, init, passDown, passUp, printStats, providedDownServices, receiveDownEvent, receiveUpEvent, requiredDownServices, requiredUpServices, setDownProtocol, setObserver, setPropertiesInternal, setProtocolStack, setUpProtocol, startDownHandler, startUpHandler, statsEnabled, stopInternal, upThreadEnabled

Methods inherited from class java.lang.Object

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

Constructor Detail

TCPGOSSIP

public TCPGOSSIP()

Method Detail

getName

public java.lang.String getName()

Specified by:

getName in class Protocol

setProperties

public boolean setProperties(java.util.Properties props)

Description copied from class: Discovery

sets the properties of the PING protocol. The following properties are available property: timeout - the timeout (ms) to wait for the initial members, default is 3000=3 secs property: num_initial_members - the minimum number of initial members for a FIND_INITAL_MBRS, default is 2

Overrides:

setProperties in class Discovery

Parameters:

props - - a property set

Returns:

returns true if all properties were parsed properly returns false if there are unrecnogized properties in the property set

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

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 Protocol

handleConnectOK

public void handleConnectOK()

Description copied from class: Discovery

Called when CONNECT_OK has been received

Overrides:

handleConnectOK in class Discovery

sendGetMembersRequest

public void sendGetMembersRequest()

Specified by:

sendGetMembersRequest in class Discovery