Class OrderInterceptor

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

  • Field Details

    • sm

      protected static final StringManager sm
      String manager for internationalization.

  • Constructor Details

    • OrderInterceptor

      public OrderInterceptor()
      Constructs an OrderInterceptor.

  • 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:

    • 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)
      Processes leftover messages for a member.
      Parameters:
      member - The member
      force - Whether to force processing

    • processIncoming

      protected boolean processIncoming(OrderInterceptor.MessageOrder order)
      Processes incoming messages, handling expiration and ordering.
      Parameters:
      order - The message order to process
      Returns:
      true if a message expired and was processed

    • 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:

    • incCounter

      protected int incCounter(Member mbr)
      Increments the outgoing message counter for a member.
      Parameters:
      mbr - The member
      Returns:
      The new counter value

    • getInCounter

      protected OrderInterceptor.Counter getInCounter(Member mbr)
      Returns the incoming counter for a member, creating one if needed.
      Parameters:
      mbr - The member
      Returns:
      The counter

    • getOutCounter

      protected OrderInterceptor.Counter getOutCounter(Member mbr)
      Returns the outgoing counter for a member, creating one if needed.
      Parameters:
      mbr - The member
      Returns:
      The counter

    • setExpire

      public void setExpire(long expire)
      Sets the message expiration time in milliseconds.
      Parameters:
      expire - The expiration time

    • setForwardExpired

      public void setForwardExpired(boolean forwardExpired)
      Sets whether expired messages should be forwarded.
      Parameters:
      forwardExpired - true to forward expired messages

    • setMaxQueue

      public void setMaxQueue(int maxQueue)
      Sets the maximum queue size.
      Parameters:
      maxQueue - The maximum queue size

    • getExpire

      public long getExpire()
      Returns the message expiration time in milliseconds.
      Returns:
      The expiration time

    • getForwardExpired

      public boolean getForwardExpired()
      Returns whether expired messages are forwarded.
      Returns:
      true if expired messages are forwarded

    • getMaxQueue

      public int getMaxQueue()
      Returns the maximum queue size.
      Returns:
      The maximum queue size