Package org.jgroups.protocols

Class TIME

java.lang.Object

org.jgroups.stack.Protocol

org.jgroups.protocols.TIME

All Implemented Interfaces:

Lifecycle

public class TIME
extends Protocol

Protocol measuring delivery times. Can be used in the up or down direction JIRA: https://issues.redhat.com/browse/JGRP-2101

Since:

4.0

Author:

Bela Ban

Field Summary

Fields

Modifier and Type	Field	Description
protected AverageMinMax	avg_up_batch_size
protected AverageMinMax	down_delivery
protected boolean	down_msgs
protected boolean	up_batches
protected AverageMinMax	up_delivery_batches
protected AverageMinMax	up_delivery_msgs
protected boolean	up_msgs

Fields inherited from class org.jgroups.stack.Protocol

after_creation_hook, down_prot, ergonomics, id, local_addr, log, policies, stack, stats, up_prot

Constructor Summary

Constructors

Constructor	Description
TIME()

Method Summary

Modifier and Type	Method	Description
protected static void	add(AverageMinMax avg, long num)
protected static double	avgTimePerMessageIncludingDelay(int num, long time)
java.lang.Object	down(Message msg)	A message is sent down the stack.
void	resetStats()
java.lang.Object	up(Message msg)	A single message was received.
void	up(MessageBatch batch)	Dividing the delivery time for a batch by the batch size is problematic, e.g.

Methods inherited from class org.jgroups.stack.Protocol

accept, addPolicy, addr, addr, afterCreationHook, destroy, down, down, enableStats, getAddress, getComponents, getDownProtocol, getDownServices, getId, getIdsAbove, getLevel, getLog, getName, getPolicies, getProtocolStack, getSocketFactory, getThreadFactory, getTransport, getUpProtocol, getUpServices, getValue, init, isErgonomics, level, parse, policies, providedDownServices, providedUpServices, removePolicy, requiredDownServices, requiredUpServices, resetStatistics, setAddress, setDownProtocol, setErgonomics, setId, setLevel, setPolicies, setProtocolStack, setSocketFactory, setUpProtocol, setValue, start, statsEnabled, stop, toString, up

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

up_delivery_msgs

protected final AverageMinMax up_delivery_msgs

up_delivery_batches

protected final AverageMinMax up_delivery_batches

avg_up_batch_size

protected final AverageMinMax avg_up_batch_size

down_delivery

protected final AverageMinMax down_delivery

down_msgs

protected boolean down_msgs

up_batches

protected boolean up_batches

up_msgs

protected boolean up_msgs

Constructor Detail

TIME

public TIME()

Method Detail

resetStats

public void resetStats()

Overrides:

resetStats in class Protocol

down

public java.lang.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 java.lang.Object up(Message msg)

Description copied from class: Protocol

A single message was received. Protocols may examine the message and do something (e.g. add a header) with it before passing it up.

Overrides:

up in class Protocol

up

public void up(MessageBatch batch)

Dividing the delivery time for a batch by the batch size is problematic, e.g. if a batch of 5 is received at time 0 and the 5 messages are delivered at times 20, 40, 60, 80 and 100, then the total time is 100, divided by 5 would be 20 per message.
However, this is incorrect as it ignores the waiting times for the individual messages: e.g. message 3 gets delayed for 60 until it is processed.
The correct average delivery time per message is therefore (20+40+60+80+100)/5 = 60.
The above computation is not correct: we don't know whether a protocol looks at all messages: it may even remove some (making 'size' incorrect)!
Also, we don't know whether messages in a batch are processed in order, on by one, or whether they are processed in parallel. Therefore, times for individual messages will not be computed.

Overrides:

up in class Protocol

Parameters:

batch - The message batch

avgTimePerMessageIncludingDelay

protected static double avgTimePerMessageIncludingDelay(int num,
                                                        long time)

add

protected static void add(AverageMinMax avg,
                          long num)