Package org.jgroups.protocols

Class RED

java.lang.Object
org.jgroups.stack.Protocol
org.jgroups.protocols.RED
All Implemented Interfaces:
Lifecycle
public class RED extends Protocol
Implementation of Random Early Drop: messages are discarded when the bundler's queue in the transport nears exhaustion. See Floyd and Van Jacobsen's paper for details.
Since:
5.0.0, 4.2.2

  • Field Details

    • enabled

      protected boolean enabled

    • queue_capacity

      protected int queue_capacity

    • min_threshold

      protected double min_threshold

    • min

      protected long min

    • max_threshold

      protected double max_threshold

    • max

      protected long max

    • avg_queue_size

      protected double avg_queue_size

    • weight_factor

      protected double weight_factor

    • dropped_msgs

      protected final LongAdder dropped_msgs

    • total_msgs

      protected final LongAdder total_msgs

    • bundler

      protected Bundler bundler

    • lock

      protected final Lock lock

    • span

      protected long span

    • weight

      protected double weight

  • Constructor Details

    • RED

      public RED()

  • Method Details

    • isEnabled

      public boolean isEnabled()

    • setEnabled

      public RED setEnabled(boolean e)

    • getMinThreshold

      public double getMinThreshold()

    • getDroppedMessages

      @Deprecated public long getDroppedMessages()
      Deprecated.
      Don't remove! https://issues.redhat.com/browse/JGRP-2814

    • getTotalMessages

      @Deprecated public long getTotalMessages()
      Deprecated.
      Don't remove! https://issues.redhat.com/browse/JGRP-2814

    • getDropRate

      public double getDropRate()

    • start

      public void start() throws Exception
      Description copied from class: Protocol
      This method is called on a JChannel.connect(String); starts work. Protocols are connected ready to receive events. Will be called from bottom to top.
      Specified by:
      start in interface Lifecycle
      Overrides:
      start in class Protocol
      Throws:
      Exception - Thrown if protocol cannot be started successfully. This will cause the ProtocolStack to fail, so JChannel.connect(String) will throw an exception

    • resetStats

      public void resetStats()
      Overrides:
      resetStats in class Protocol

    • down

      public Object down(Message msg)
      Description copied from class: Protocol
      A message is sent down the stack. Protocols may examine the message and do something (e.g. add a header) with it, before passing it down.
      Overrides:
      down in class Protocol

    • up

      public void up(MessageBatch batch)
      Description copied from class: Protocol
      Sends up a multiple messages in a MessageBatch. The sender of the batch is always the same, and so is the destination (null == multicast messages). Messages in a batch can be OOB messages, regular messages, or mixed messages, although the transport itself will create initial MessageBatches that contain only either OOB or regular messages.

      The default processing below sends messages up the stack individually, based on a matching criteria (calling Protocol.accept(Message)), and - if true - calls Protocol.up(org.jgroups.Event) for that message and removes the message. If the batch is not empty, it is passed up, or else it is dropped.

      Subclasses should check if there are any messages destined for them (e.g. using MessageBatch.iterator(Predicate)), then possibly remove and process them and finally pass the batch up to the next protocol. Protocols can also modify messages in place, e.g. ENCRYPT could decrypt all encrypted messages in the batch, not remove them, and pass the batch up when done.

      Overrides:
      up in class Protocol
      Parameters:
      batch - The message batch

    • toString

      public String toString()
      Overrides:
      toString in class Protocol

    • computeAverage

      protected double computeAverage(double old_avg, int new_queue_size)

    • computeDropProbability

      protected double computeDropProbability(double avg)
      Computes a probability P with which the message should get dropped. min_threshold < avg < max_threshold. Probability increases linearly with min moving toward max

    • drop

      protected boolean drop(double avg)

    • checkRange

      protected static double checkRange(double val, double min, double max, String name)