org.apache.catalina.tribes.group.interceptors
Class TcpFailureDetector

java.lang.Object
  org.apache.catalina.tribes.group.ChannelInterceptorBase
      org.apache.catalina.tribes.group.interceptors.TcpFailureDetector

All Implemented Interfaces:

ChannelInterceptor, Heartbeat, MembershipListener

public class TcpFailureDetector
extends ChannelInterceptorBase

Title: A perfect failure detector

Description: The TcpFailureDetector is a useful interceptor that adds reliability to the membership layer.

If the network is busy, or the system is busy so that the membership receiver thread is not getting enough time to update its table, members can be "timed out" This failure detector will intercept the memberDisappeared message(unless its a true shutdown message) and connect to the member using TCP.

The TcpFailureDetector works in two ways.
1. It intercepts memberDisappeared events 2. It catches send errors

Version:

1.0

Author:

Filip Hanik

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.catalina.tribes.ChannelInterceptor

ChannelInterceptor.InterceptorEvent

Field Summary

protected HashMap<Member,Long>	addSuspects
protected long	connectTimeout
protected Membership	membership
protected boolean	performConnectTest
protected boolean	performReadTest
protected boolean	performSendTest
protected long	readTestTimeout
protected HashMap<Member,Long>	removeSuspects
protected static byte[]	TCP_FAIL_DETECT

Fields inherited from class org.apache.catalina.tribes.group.ChannelInterceptorBase

optionFlag

Constructor Summary

TcpFailureDetector()

Method Summary

void	checkMembers(boolean checkAll)
long	getConnectTimeout()
Member	getLocalMember(boolean incAlive) Return the member that represents this node.
Member	getMember(Member mbr) Intercepts the code>Channel.getMember(Member) method
Member[]	getMembers() Get all current cluster members
boolean	getPerformConnectTest()
boolean	getPerformReadTest()
boolean	getPerformSendTest()
long	getReadTestTimeout()
boolean	hasMembers() has members
void	heartbeat() The heartbeat() method gets invoked periodically to allow interceptors to clean up resources, time out object and perform actions that are unrelated to sending/receiving data.
void	memberAdded(Member member) A member was added to the group
protected boolean	memberAlive(Member mbr)
protected static boolean	memberAlive(Member mbr, byte[] msgData, boolean sendTest, boolean readTest, long readTimeout, long conTimeout, int optionFlag)
void	memberDisappeared(Member member) A member was removed from the group If the member left voluntarily, the Member.getCommand will contain the Member.SHUTDOWN_PAYLOAD data
void	messageReceived(ChannelMessage msg) the messageReceived is invoked when a message is received.
protected void	performBasicCheck()
protected void	performForcedCheck()
void	sendMessage(Member[] destination, ChannelMessage msg, InterceptorPayload payload) The sendMessage method is called when a message is being sent to one more destinations.
void	setConnectTimeout(long connectTimeout)
void	setPerformConnectTest(boolean performConnectTest)
void	setPerformReadTest(boolean performReadTest)
void	setPerformSendTest(boolean performSendTest)
void	setReadTestTimeout(long readTestTimeout)
protected void	setupMembership()

Methods inherited from class org.apache.catalina.tribes.group.ChannelInterceptorBase

accept, fireInterceptorEvent, getNext, getOptionFlag, getPrevious, okToProcess, setNext, setOptionFlag, setPrevious, start, stop

Methods inherited from class java.lang.Object

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

Field Detail

TCP_FAIL_DETECT

protected static byte[] TCP_FAIL_DETECT

performConnectTest

protected boolean performConnectTest

connectTimeout

protected long connectTimeout

performSendTest

protected boolean performSendTest

performReadTest

protected boolean performReadTest

readTestTimeout

protected long readTestTimeout

membership

protected Membership membership

removeSuspects

protected HashMap<Member,Long> removeSuspects

addSuspects

protected HashMap<Member,Long> addSuspects

Constructor Detail

TcpFailureDetector

public TcpFailureDetector()

Method Detail

sendMessage

public void sendMessage(Member[] destination,
                        ChannelMessage msg,
                        InterceptorPayload payload)
                 throws ChannelException

Description copied from interface: ChannelInterceptor

The sendMessage method is called when a message is being sent to one more destinations. The interceptor can modify any of the parameters and then pass on the message down the stack by invoking getNext().sendMessage(destination,msg,payload)
Alternatively the interceptor can stop the message from being sent by not invoking getNext().sendMessage(destination,msg,payload)
If the message is to be sent asynchronous the application can be notified of completion and errors by passing in an error handler attached to a payload object.
The ChannelMessage.getAddress contains Channel.getLocalMember, and can be overwritten to simulate a message sent from another node.

Specified by:

sendMessage in interface ChannelInterceptor

Overrides:

sendMessage in class ChannelInterceptorBase

Parameters:

destination - Member[] - the destination for this message

msg - ChannelMessage - the message to be sent

payload - InterceptorPayload - the payload, carrying an error handler and future useful data, can be null

Throws:

ChannelException

See Also:

ErrorHandler, InterceptorPayload

messageReceived

public void messageReceived(ChannelMessage msg)

Description copied from interface: ChannelInterceptor

the messageReceived is invoked when a message is received. ChannelMessage.getAddress() is the sender, or the reply-to address if it has been overwritten.

Specified by:

messageReceived in interface ChannelInterceptor

Overrides:

messageReceived in class ChannelInterceptorBase

Parameters:

msg - ChannelMessage

memberAdded

public void memberAdded(Member member)

Description copied from interface: MembershipListener

A member was added to the group

Specified by:

memberAdded in interface MembershipListener

Overrides:

memberAdded in class ChannelInterceptorBase

Parameters:

member - Member - the member that was added

memberDisappeared

public void memberDisappeared(Member member)

Description copied from interface: MembershipListener

A member was removed from the group
If the member left voluntarily, the Member.getCommand will contain the Member.SHUTDOWN_PAYLOAD data

Specified by:

memberDisappeared in interface MembershipListener

Overrides:

memberDisappeared in class ChannelInterceptorBase

Parameters:

member - Member

See Also:

Member.SHUTDOWN_PAYLOAD

hasMembers

public boolean hasMembers()

Description copied from class: ChannelInterceptorBase

has members

Specified by:

hasMembers in interface ChannelInterceptor

Overrides:

hasMembers in class ChannelInterceptorBase

Returns:

boolean - if the channel has members in its membership group

See Also:

Channel.hasMembers()

getMembers

public Member[] getMembers()

Description copied from class: ChannelInterceptorBase

Get all current cluster members

Specified by:

getMembers in interface ChannelInterceptor

Overrides:

getMembers in class ChannelInterceptorBase

Returns:

all members or empty array

See Also:

Channel.getMembers()

getMember

public Member getMember(Member mbr)

Description copied from interface: ChannelInterceptor

Intercepts the code>Channel.getMember(Member) method

Specified by:

getMember in interface ChannelInterceptor

Overrides:

getMember in class ChannelInterceptorBase

Parameters:

mbr - Member

Returns:

Member

See Also:

Channel.getMember(Member)

getLocalMember

public Member getLocalMember(boolean incAlive)

Description copied from class: ChannelInterceptorBase

Return the member that represents this node.

Specified by:

getLocalMember in interface ChannelInterceptor

Overrides:

getLocalMember in class ChannelInterceptorBase

Parameters:

incAlive - boolean

Returns:

Member

See Also:

Channel.getLocalMember(boolean)

heartbeat

public void heartbeat()

Description copied from interface: ChannelInterceptor

The heartbeat() method gets invoked periodically to allow interceptors to clean up resources, time out object and perform actions that are unrelated to sending/receiving data.

Specified by:

heartbeat in interface ChannelInterceptor

Specified by:

heartbeat in interface Heartbeat

Overrides:

heartbeat in class ChannelInterceptorBase

checkMembers

public void checkMembers(boolean checkAll)

performForcedCheck

protected void performForcedCheck()

performBasicCheck

protected void performBasicCheck()

setupMembership

protected void setupMembership()

memberAlive

protected boolean memberAlive(Member mbr)

memberAlive

protected static boolean memberAlive(Member mbr,
                                     byte[] msgData,
                                     boolean sendTest,
                                     boolean readTest,
                                     long readTimeout,
                                     long conTimeout,
                                     int optionFlag)

getPerformConnectTest

public boolean getPerformConnectTest()

getReadTestTimeout

public long getReadTestTimeout()

getPerformSendTest

public boolean getPerformSendTest()

getPerformReadTest

public boolean getPerformReadTest()

getConnectTimeout

public long getConnectTimeout()

setPerformConnectTest

public void setPerformConnectTest(boolean performConnectTest)

setPerformReadTest

public void setPerformReadTest(boolean performReadTest)

setPerformSendTest

public void setPerformSendTest(boolean performSendTest)

setReadTestTimeout

public void setReadTestTimeout(long readTestTimeout)

setConnectTimeout

public void setConnectTimeout(long connectTimeout)