Package 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`, `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 final HashMap<Member,Long>`
`addSuspects`
`protected long`
`connectTimeout`
`protected Membership`
`membership`
`protected boolean`
`performReadTest`
`protected boolean`
`performSendTest`
`protected long`
`readTestTimeout`
`protected final HashMap<Member,Long>`
`removeSuspects`
`protected int`
`removeSuspectsTimeout`
`protected static final StringManager`
`sm`
`protected static final byte[]`
`TCP_FAIL_DETECT`

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

`optionFlag`

## Constructor Summary

Constructors
Constructor
Description
`TcpFailureDetector()`

## Method Summary

Modifier and Type
Method
Description
`void`
`checkMembers(boolean checkAll)`
`long`
`getConnectTimeout()`
`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()`
`boolean`
`getPerformSendTest()`
`long`
`getReadTestTimeout()`
`int`
`getRemoveSuspectsTimeout()`
`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)`
`protected 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`
`setPerformReadTest(boolean performReadTest)`
`void`
`setPerformSendTest(boolean performSendTest)`
`void`
`setReadTestTimeout(long readTestTimeout)`
`void`
`setRemoveSuspectsTimeout(int removeSuspectsTimeout)`
`protected void`
`setupMembership()`

### 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 Details

### sm

protected static final StringManager sm

### TCP_FAIL_DETECT

protected static final byte[] TCP_FAIL_DETECT

### connectTimeout

protected long connectTimeout

### performSendTest

protected boolean performSendTest

### performReadTest

protected boolean performReadTest

### readTestTimeout

protected long readTestTimeout

### membership

protected Membership membership

### removeSuspects

protected final HashMap<Member,Long> removeSuspects

### addSuspects

protected final HashMap<Member,Long> addSuspects

### removeSuspectsTimeout

protected int removeSuspectsTimeout

## Constructor Details

### TcpFailureDetector

public 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)

Specified by:
  `checkMembers` in interface `TcpFailureDetectorMBean`

### performForcedCheck

protected void performForcedCheck()

### performBasicCheck

protected void performBasicCheck()

### setupMembership

protected void setupMembership()

### memberAlive

protected boolean memberAlive(Member mbr)

### memberAlive

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

### getReadTestTimeout

public long getReadTestTimeout()

Specified by:
  `getReadTestTimeout` in interface `TcpFailureDetectorMBean`

### getPerformSendTest

public boolean getPerformSendTest()

Specified by:
  `getPerformSendTest` in interface `TcpFailureDetectorMBean`

### getPerformReadTest

public boolean getPerformReadTest()

Specified by:
  `getPerformReadTest` in interface `TcpFailureDetectorMBean`

### getConnectTimeout

public long getConnectTimeout()

Specified by:
  `getConnectTimeout` in interface `TcpFailureDetectorMBean`

### getRemoveSuspectsTimeout

public int getRemoveSuspectsTimeout()

Specified by:
  `getRemoveSuspectsTimeout` in interface `TcpFailureDetectorMBean`

### setPerformReadTest

public void setPerformReadTest(boolean performReadTest)

Specified by:
  `setPerformReadTest` in interface `TcpFailureDetectorMBean`

### setPerformSendTest

public void setPerformSendTest(boolean performSendTest)

Specified by:
  `setPerformSendTest` in interface `TcpFailureDetectorMBean`

### setReadTestTimeout

public void setReadTestTimeout(long readTestTimeout)

Specified by:
  `setReadTestTimeout` in interface `TcpFailureDetectorMBean`

### setConnectTimeout

public void setConnectTimeout(long connectTimeout)

Specified by:
  `setConnectTimeout` in interface `TcpFailureDetectorMBean`

### setRemoveSuspectsTimeout

public void setRemoveSuspectsTimeout(int removeSuspectsTimeout)

Specified by:
  `setRemoveSuspectsTimeout` in interface `TcpFailureDetectorMBean`