OrderInterceptor (Apache Tomcat 7.0.109 API Documentation)

java.lang.Object
- org.apache.catalina.tribes.group.ChannelInterceptorBase
- - org.apache.catalina.tribes.group.interceptors.OrderInterceptor

All Implemented Interfaces:

ChannelInterceptor, Heartbeat, MembershipListener
```
public class OrderInterceptor
extends ChannelInterceptorBase
```
The order interceptor guarantees that messages are received in the same order they were sent. This interceptor works best with the ack=true setting.
There is no point in using this with the replicationMode="fastasynchqueue" as this mode guarantees ordering.
If you are using the mode ack=false replicationMode=pooled, and have a lot of concurrent threads, this interceptor can really slow you down, as many messages will be completely out of order and the queue might become rather large. If this is the case, then you might want to set the value OrderInterceptor.maxQueue = 25 (meaning that we will never keep more than 25 messages in our queue)
Configuration Options
OrderInterceptor.expire=<milliseconds> - if a message arrives out of order, how long before we act on it default=3000ms
OrderInterceptor.maxQueue=<max queue size> - how much can the queue grow to ensure ordering. This setting is useful to avoid OutOfMemoryErrorsdefault=Integer.MAX_VALUE
OrderInterceptor.forwardExpired=<boolean> - this flag tells the interceptor what to do when a message has expired or the queue has grown larger than the maxQueue value. true means that the message is sent up the stack to the receiver that will receive and out of order message false means, forget the message and reset the message counter. default=true

Version:

1.1

Author:

Filip Hanik

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

protected static class OrderInterceptor.Counter

protected static class OrderInterceptor.MessageOrder
- Nested classes/interfaces inherited from interface org.apache.catalina.tribes.ChannelInterceptor
  ChannelInterceptor.InterceptorEvent

Nested Classes
Modifier and Type	Class and Description
`protected static class`	`OrderInterceptor.Counter`
`protected static class`	`OrderInterceptor.MessageOrder`

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

Constructor Summary

Constructors
Constructor and Description

OrderInterceptor()

Constructors
Constructor and Description
`OrderInterceptor()`

Method Summary

Methods
Modifier and Type	Method and Description
`long`	`getExpire()`
`boolean`	`getForwardExpired()`
`protected OrderInterceptor.Counter`	`getInCounter(Member mbr)`
`int`	`getMaxQueue()`
`protected OrderInterceptor.Counter`	`getOutCounter(Member mbr)`
`protected int`	`incCounter(Member mbr)`
`void`	`memberAdded(Member member)` A member was added to the group
`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 boolean`	`processIncoming(OrderInterceptor.MessageOrder order)`
`protected void`	`processLeftOvers(Member member, boolean force)`
`void`	`sendMessage(Member[] destination, ChannelMessage msg, InterceptorPayload payload)` The `sendMessage` method is called when a message is being sent to one more destinations.
`void`	`setExpire(long expire)`
`void`	`setForwardExpired(boolean forwardExpired)`
`void`	`setMaxQueue(int maxQueue)`

Methods inherited from class org.apache.catalina.tribes.group.ChannelInterceptorBase
accept, fireInterceptorEvent, getChannel, getLocalMember, getMember, getMembers, getNext, getOptionFlag, getPrevious, hasMembers, heartbeat, 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

- Constructor Detail
  - OrderInterceptor
```
public OrderInterceptor()
```
- 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
  - processLeftOvers
```
protected void processLeftOvers(Member member,
                    boolean force)
```
  - processIncoming
```
protected boolean processIncoming(OrderInterceptor.MessageOrder order)
```
    Parameters:
    order - MessageOrder
    
    Returns:
    boolean - true if a message expired and was processed
  - 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
  - incCounter
```
protected int incCounter(Member mbr)
```
  - getInCounter
```
protected OrderInterceptor.Counter getInCounter(Member mbr)
```
  - getOutCounter
```
protected OrderInterceptor.Counter getOutCounter(Member mbr)
```
  - setExpire
```
public void setExpire(long expire)
```
  - setForwardExpired
```
public void setForwardExpired(boolean forwardExpired)
```
  - setMaxQueue
```
public void setMaxQueue(int maxQueue)
```
  - getExpire
```
public long getExpire()
```
  - getForwardExpired
```
public boolean getForwardExpired()
```
  - getMaxQueue
```
public int getMaxQueue()
```

Class OrderInterceptor

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

Constructor Detail

OrderInterceptor

Method Detail

sendMessage

messageReceived

processLeftOvers

processIncoming

memberAdded

memberDisappeared

incCounter

getInCounter

getOutCounter

setExpire

setForwardExpired

setMaxQueue

getExpire

getForwardExpired

getMaxQueue