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

Nested Class Summary

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

Discovery.Responses

Field Summary

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, view

Fields inherited from class org.jgroups.stack.Protocol

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

Constructor Summary

Constructors

Constructor and Description
TCPGOSSIP()

Method Summary

Methods

Modifier and Type	Method and Description
void	addInitialHost(String hostname, int port)
protected void	connect(RouterStub stub, String group, Address logical_addr)
protected void	connectAllStubs(String group, Address logical_addr)
void	destroy() This method is called on a Channel.close().
Collection<PhysicalAddress>	fetchClusterMembers(String cluster_name) Grab all current cluster members
List<InetSocketAddress>	getInitialHosts()
void	handleConnect()
void	handleDisconnect()
void	init() Called after instance has been created (null constructor) and before protocol is started.
boolean	isDynamic()
boolean	removeInitialHost(String hostname, int port)
boolean	sendDiscoveryRequestsInParallel() Whether or not to send each discovery request on a separate (timer) thread.
void	setInitialHosts(List<InetSocketAddress> hosts)
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

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

Methods inherited from class org.jgroups.stack.Protocol

dumpStats, enableStats, getConfigurableObjects, getDownProtocol, getId, getLevel, getName, getProtocolStack, getSocketFactory, getThreadFactory, getTransport, getUpProtocol, 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

Constructor Detail

TCPGOSSIP

public TCPGOSSIP()

Method Detail

setInitialHosts

public void setInitialHosts(List<InetSocketAddress> hosts)

getInitialHosts

public List<InetSocketAddress> getInitialHosts()

isDynamic

public boolean isDynamic()

Specified by:

isDynamic in class Discovery

init

public void init()
          throws 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:

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 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:

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

handleConnect

public void handleConnect()

Overrides:

handleConnect in class Discovery

handleDisconnect

public void handleDisconnect()

Overrides:

handleDisconnect in class Discovery

fetchClusterMembers

public Collection<PhysicalAddress> fetchClusterMembers(String cluster_name)

Description copied from class: Discovery

Grab all current cluster members

Specified by:

fetchClusterMembers in class Discovery

Returns:

A list of the cluster members (usually IpAddresses), or null if the transport is multicast-enabled. Returns an empty list if no cluster members could be found.

sendDiscoveryRequestsInParallel

public boolean sendDiscoveryRequestsInParallel()

Description copied from class: Discovery

Whether or not to send each discovery request on a separate (timer) thread. If disabled, a discovery request will be sent to all members fetched by Discovery.fetchClusterMembers(String) sequentially

Specified by:

sendDiscoveryRequestsInParallel in class Discovery

addInitialHost

public void addInitialHost(String hostname,
                  int port)

removeInitialHost

public boolean removeInitialHost(String hostname,
                        int port)

connectAllStubs

protected void connectAllStubs(String group,
                   Address logical_addr)

connect

protected void connect(RouterStub stub,
           String group,
           Address logical_addr)