Class TcpFailureDetector

java.lang.Object

org.apache.catalina.tribes.group.ChannelInterceptorBase

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

All Implemented Interfaces:

ChannelInterceptor, TcpFailureDetectorMBean, Heartbeat, MembershipListener

public class TcpFailureDetector
extends ChannelInterceptorBase
implements TcpFailureDetectorMBean

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

Nested Class Summary

Nested classes/interfaces inherited from interface ChannelInterceptor

ChannelInterceptor.InterceptorEvent

Field Summary

Fields

Modifier and Type	Field	Description
protected final HashMap<Member,Long>	addSuspects	Map of members suspected of rejoining and their detection time.
protected long	connectTimeout	Connection timeout in milliseconds for member checks.
protected Membership	membership	The membership tracker.
protected boolean	performReadTest	Whether to perform TCP read tests during member checks.
protected boolean	performSendTest	Whether to perform TCP send tests during member checks.
protected long	readTestTimeout	Read test timeout in milliseconds.
protected final HashMap<Member,Long>	removeSuspects	Map of members suspected of being dead and their detection time.
protected int	removeSuspectsTimeout	Timeout in seconds for removing suspected dead members.
protected static final StringManager	sm	The string manager for this package.
protected static final byte[]	TCP_FAIL_DETECT	Test payload sent during member liveness checks.

Fields inherited from class ChannelInterceptorBase

optionFlag

Constructor Summary

Constructors

Constructor	Description
TcpFailureDetector()	Constructs a new TcpFailureDetector.

Method Summary

Modifier and Type	Method	Description
void	checkMembers(boolean checkAll)	Checks the status of cluster members.
long	getConnectTimeout()	Returns the connection timeout in milliseconds.
Member	getLocalMember(boolean incAlive)	Intercepts the Channel.getLocalMember(boolean) method
Member	getMember(Member mbr)	Intercepts the Channel.getMember(Member) method
Member[]	getMembers()	Intercepts the Channel.getMembers() method
boolean	getPerformReadTest()	Returns whether read tests are performed.
boolean	getPerformSendTest()	Returns whether send tests are performed.
long	getReadTestTimeout()	Returns the read test timeout in milliseconds.
int	getRemoveSuspectsTimeout()	Returns the timeout for removing suspects.
boolean	hasMembers()	Intercepts the Channel.hasMembers() method
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)	Checks whether the given member is alive using the default test parameters.
protected boolean	memberAlive(Member mbr, byte[] msgData, boolean sendTest, boolean readTest, long readTimeout, long conTimeout, int optionFlag)	Checks whether the given member is alive using the specified test parameters.
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()	Performs a basic check of suspected members.
protected void	performForcedCheck()	Performs a forced check of all cluster members.
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)	Sets the connection timeout in milliseconds.
void	setPerformReadTest(boolean performReadTest)	Sets whether read tests should be performed.
void	setPerformSendTest(boolean performSendTest)	Sets whether send tests should be performed.
void	setReadTestTimeout(long readTestTimeout)	Sets the read test timeout in milliseconds.
void	setRemoveSuspectsTimeout(int removeSuspectsTimeout)	Sets the timeout for removing suspects.
protected void	setupMembership()	Initializes the membership tracker if not already set up.

Methods inherited from class ChannelInterceptorBase

fireInterceptorEvent, getChannel, getNext, getOptionFlag, getPrevious, okToProcess, setChannel, setNext, setOptionFlag, setPrevious, start, stop

Methods inherited from class Object

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

Methods inherited from interface TcpFailureDetectorMBean

getOptionFlag

Field Details

sm

protected static final StringManager sm

The string manager for this package.

TCP_FAIL_DETECT

protected static final byte[] TCP_FAIL_DETECT

Test payload sent during member liveness checks.

connectTimeout

protected long connectTimeout

Connection timeout in milliseconds for member checks.

performSendTest

protected boolean performSendTest

Whether to perform TCP send tests during member checks.

performReadTest

protected boolean performReadTest

Whether to perform TCP read tests during member checks.

readTestTimeout

protected long readTestTimeout

Read test timeout in milliseconds.

membership

protected Membership membership

The membership tracker.

removeSuspects

protected final HashMap<Member,Long> removeSuspects

Map of members suspected of being dead and their detection time.

addSuspects

protected final HashMap<Member,Long> addSuspects

Map of members suspected of rejoining and their detection time.

removeSuspectsTimeout

protected int removeSuspectsTimeout

Timeout in seconds for removing suspected dead members.

Constructor Details

TcpFailureDetector

public TcpFailureDetector()

Constructs a new TcpFailureDetector.

Method Details

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 - if a serialization error happens.

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 interface: ChannelInterceptor

Intercepts the Channel.hasMembers() method

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 interface: ChannelInterceptor

Intercepts the Channel.getMembers() method

Specified by:

getMembers in interface ChannelInterceptor

Overrides:

getMembers in class ChannelInterceptorBase

Returns:

the members

See Also:

• Channel.getMembers()

getMember

public Member getMember(Member mbr)

Description copied from interface: ChannelInterceptor

Intercepts the Channel.getMember(Member) method

Specified by:

getMember in interface ChannelInterceptor

Overrides:

getMember in class ChannelInterceptorBase

Parameters:

mbr - Member

Returns:

Member - the actual member information, including stay alive

See Also:

• Channel.getMember(Member)

getLocalMember

public Member getLocalMember(boolean incAlive)

Description copied from interface: ChannelInterceptor

Intercepts the Channel.getLocalMember(boolean) method

Specified by:

getLocalMember in interface ChannelInterceptor

Overrides:

getLocalMember in class ChannelInterceptorBase

Parameters:

incAlive - boolean

Returns:

the member that represents this node

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)

Description copied from interface: TcpFailureDetectorMBean

Checks the status of cluster members.

Specified by:

checkMembers in interface TcpFailureDetectorMBean

Parameters:

checkAll - true to check all members, false to check only suspects

performForcedCheck

protected void performForcedCheck()

Performs a forced check of all cluster members.

performBasicCheck

protected void performBasicCheck()

Performs a basic check of suspected members.

setupMembership

protected void setupMembership()

Initializes the membership tracker if not already set up.

memberAlive

protected boolean memberAlive(Member mbr)

Checks whether the given member is alive using the default test parameters.

Parameters:

mbr - the member to check

Returns:

true if the member is alive

memberAlive

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

Checks whether the given member is alive using the specified test parameters.

Parameters:

mbr - the member to check

msgData - the test message data

sendTest - whether to perform a send test

readTest - whether to perform a read test

readTimeout - the read timeout in milliseconds

conTimeout - the connection timeout in milliseconds

optionFlag - the socket option flag

Returns:

true if the member is alive

getReadTestTimeout

public long getReadTestTimeout()

Description copied from interface: TcpFailureDetectorMBean

Returns the read test timeout in milliseconds.

Specified by:

getReadTestTimeout in interface TcpFailureDetectorMBean

Returns:

the read test timeout

getPerformSendTest

public boolean getPerformSendTest()

Description copied from interface: TcpFailureDetectorMBean

Returns whether send tests are performed.

Specified by:

getPerformSendTest in interface TcpFailureDetectorMBean

Returns:

true if send tests are enabled

getPerformReadTest

public boolean getPerformReadTest()

Description copied from interface: TcpFailureDetectorMBean

Returns whether read tests are performed.

Specified by:

getPerformReadTest in interface TcpFailureDetectorMBean

Returns:

true if read tests are enabled

getConnectTimeout

public long getConnectTimeout()

Description copied from interface: TcpFailureDetectorMBean

Returns the connection timeout in milliseconds.

Specified by:

getConnectTimeout in interface TcpFailureDetectorMBean

Returns:

the connection timeout

getRemoveSuspectsTimeout

public int getRemoveSuspectsTimeout()

Description copied from interface: TcpFailureDetectorMBean

Returns the timeout for removing suspects.

Specified by:

getRemoveSuspectsTimeout in interface TcpFailureDetectorMBean

Returns:

the remove suspects timeout

setPerformReadTest

public void setPerformReadTest(boolean performReadTest)

Description copied from interface: TcpFailureDetectorMBean

Sets whether read tests should be performed.

Specified by:

setPerformReadTest in interface TcpFailureDetectorMBean

Parameters:

performReadTest - true to enable read tests

setPerformSendTest

public void setPerformSendTest(boolean performSendTest)

Description copied from interface: TcpFailureDetectorMBean

Sets whether send tests should be performed.

Specified by:

setPerformSendTest in interface TcpFailureDetectorMBean

Parameters:

performSendTest - true to enable send tests

setReadTestTimeout

public void setReadTestTimeout(long readTestTimeout)

Description copied from interface: TcpFailureDetectorMBean

Sets the read test timeout in milliseconds.

Specified by:

setReadTestTimeout in interface TcpFailureDetectorMBean

Parameters:

readTestTimeout - the timeout value

setConnectTimeout

public void setConnectTimeout(long connectTimeout)

Description copied from interface: TcpFailureDetectorMBean

Sets the connection timeout in milliseconds.

Specified by:

setConnectTimeout in interface TcpFailureDetectorMBean

Parameters:

connectTimeout - the timeout value

setRemoveSuspectsTimeout

public void setRemoveSuspectsTimeout(int removeSuspectsTimeout)

Description copied from interface: TcpFailureDetectorMBean

Sets the timeout for removing suspects.

Specified by:

setRemoveSuspectsTimeout in interface TcpFailureDetectorMBean

Parameters:

removeSuspectsTimeout - the timeout value