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 org.apache.catalina.tribes.ChannelInterceptor
  ChannelInterceptor.InterceptorEvent

Field Summary

Fields
Modifier and Type	Field	Description
`protected java.util.HashMap<Member,java.lang.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 java.util.HashMap<Member,java.lang.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 StringManager`	`sm`	The string manager for this package.
`protected static byte[]`	`TCP_FAIL_DETECT`	Test payload sent during member liveness checks.

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

Constructor Summary

Constructors
Constructor Description

TcpFailureDetector()
Constructs a new TcpFailureDetector.

Method Summary

All Methods Instance Methods Concrete Methods
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 org.apache.catalina.tribes.group.ChannelInterceptorBase
fireInterceptorEvent, getChannel, getNext, getOptionFlag, getPrevious, okToProcess, setChannel, setNext, setOptionFlag, setPrevious, start, stop

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.catalina.tribes.group.interceptors.TcpFailureDetectorMBean
getOptionFlag

- Field Detail
  - 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 java.util.HashMap<Member,java.lang.Long> removeSuspects
```
    Map of members suspected of being dead and their detection time.
  - addSuspects
```
protected final java.util.HashMap<Member,java.lang.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 Detail
  - TcpFailureDetector
```
public TcpFailureDetector()
```
    Constructs a new 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 - 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

Class TcpFailureDetector

Nested Class Summary

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

Field Summary

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

Constructor Summary

Method Summary

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

Methods inherited from class java.lang.Object

Methods inherited from interface org.apache.catalina.tribes.group.interceptors.TcpFailureDetectorMBean

Field Detail

sm

TCP_FAIL_DETECT

connectTimeout

performSendTest

performReadTest

readTestTimeout

membership

removeSuspects

addSuspects

removeSuspectsTimeout

Constructor Detail

TcpFailureDetector

Method Detail

sendMessage

messageReceived

memberAdded

memberDisappeared

hasMembers

getMembers

getMember

getLocalMember

heartbeat

checkMembers

performForcedCheck

performBasicCheck

setupMembership

memberAlive

memberAlive

getReadTestTimeout

getPerformSendTest

getPerformReadTest

getConnectTimeout

getRemoveSuspectsTimeout

setPerformReadTest

setPerformSendTest

setReadTestTimeout

setConnectTimeout

setRemoveSuspectsTimeout