org.jgroups.protocols

Class FD_ALL

java.lang.Object

org.jgroups.stack.Protocol

org.jgroups.protocols.FD_ALL

public class FD_ALL
extends Protocol

Failure detection based on simple heartbeat protocol. Every member periodically multicasts a heartbeat. Every member also maintains a table of all members (minus itself). When data or a heartbeat from P is received, we reset the timestamp for P to the current time. Periodically, we check for expired members, and suspect those.

Reduced number of messages exchanged on suspect event: https://jira.jboss.org/browse/JGRP-1241

Author:

Bela Ban

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FD_ALL.HeartbeatHeader

Field Summary

Fields

Modifier and Type	Field and Description
protected int	num_heartbeats_received
protected int	num_heartbeats_sent
protected int	num_suspect_events
protected Set<Address>	suspected_mbrs

Fields inherited from class org.jgroups.stack.Protocol

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

Constructor Summary

Constructors

Constructor and Description
FD_ALL()

Method Summary

Methods

Modifier and Type	Method and Description
Object	down(Event evt) An event is to be sent down the stack.
int	getHeartbeatsReceived()
int	getHeartbeatsSent()
long	getInterval()
String	getLocalAddress()
String	getMembers()
String	getSuspectedMembers()
int	getSuspectEventsSent()
long	getTimeout()
long	getTimeoutCheckInterval()
void	init() Called after instance has been created (null constructor) and before protocol is started.
boolean	isRunning()
String	printSuspectHistory()
String	printTimestamps()
void	resetStats()
void	setInterval(long interval)
void	setTimeout(long timeout)
void	setTimeoutCheckInterval(long timeout_check_interval)
void	startFailureDetection()
void	stop() This method is called on a Channel.disconnect().
void	stopFailureDetection()
Object	up(Event evt) An event was received from the layer below.

Methods inherited from class org.jgroups.stack.Protocol

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

Methods inherited from class java.lang.Object

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

Field Detail

num_heartbeats_sent

protected int num_heartbeats_sent

num_heartbeats_received

protected int num_heartbeats_received

num_suspect_events

protected int num_suspect_events

suspected_mbrs

protected final Set<Address> suspected_mbrs

Constructor Detail

FD_ALL

public FD_ALL()

Method Detail

getLocalAddress

public String getLocalAddress()

getMembers

public String getMembers()

getSuspectedMembers

public String getSuspectedMembers()

getHeartbeatsSent

public int getHeartbeatsSent()

getHeartbeatsReceived

public int getHeartbeatsReceived()

getSuspectEventsSent

public int getSuspectEventsSent()

getTimeout

public long getTimeout()

setTimeout

public void setTimeout(long timeout)

getTimeoutCheckInterval

public long getTimeoutCheckInterval()

setTimeoutCheckInterval

public void setTimeoutCheckInterval(long timeout_check_interval)

getInterval

public long getInterval()

setInterval

public void setInterval(long interval)

isRunning

public boolean isRunning()

printSuspectHistory

public String printSuspectHistory()

printTimestamps

public String printTimestamps()

stopFailureDetection

public void stopFailureDetection()

startFailureDetection

public void startFailureDetection()

resetStats

public void resetStats()

Overrides:

resetStats in class Protocol

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 Protocol

Throws:

Exception - Thrown if protocol cannot be initialized successfully. This will cause the ProtocolStack to fail, so the channel constructor 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 Protocol

up

public Object up(Event evt)

Description copied from class: Protocol

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 down_prot.down() or c) the event (or another event) is sent up the stack using up_prot.up().

Overrides:

up in class Protocol

down

public Object down(Event evt)

Description copied from class: Protocol

An event is to be sent down the stack. The layer may want to examine its type and perform some action on it, depending on the event's type. If the event is a message MSG, then the layer may need to add a header to it (or do nothing at all) before sending it down the stack using down_prot.down(). In case of a GET_ADDRESS event (which tries to retrieve the stack's address from one of the bottom layers), the layer may need to send a new response event back up the stack using up_prot.up().

Overrides:

down in class Protocol