ds.funnel.traffic

Class TrafficGenerator

java.lang.Object

ds.funnel.node.task.Task<T>

ds.funnel.node.task.ScheduledTask<java.lang.Void>

ds.funnel.traffic.TrafficGenerator

All Implemented Interfaces:

java.lang.Runnable

public class TrafficGenerator
extends ScheduledTask<java.lang.Void>

A TrafficGenerator sends some number of packets to a host (via a Link) following some sort of distribution pattern (size and spacing). The number of packets for the TrafficGenerator to send must be specified via a setter.

The TrafficGenerator's behavior can be specified further by the user in a number of ways. A TrafficGenerator has the following components:

• A PacketTimeDistribution - The provided PacketTimeDistribution controls the pattern of packet transmissions over time.
• A PacketSizeDistribution - The provided PacketTimeDistribution controls the pattern of packet sizes over time.
• A PacketGenerator - The provided PacketGenerator controls the method of packet generation and, by extension, the contents of the packets sent.
• A Link - The provided Link controls all communications with the TrafficGenerator's host. The Link passed to the TrafficGenerator should already be initialized with the information it needs to connect to the desired host, although the link itself may not yet have been established.

TrafficGenerator should be run within a thread. When started via the run() method, attempts to connect to its host; upon successful connection, sends the specified number of packets over the link, then ends.

After getting a TrafficGenerator instance via the getInstance() method, the user must specify the desired packet count, PacketTimeDistribution, PacketSizeDistribution, PacketGenerator, and Link via the corresponding setter methods. There are currently no default values for any of the aforementioned parameters. Failure to specify all parameters before running the TrafficGenerator instance will result in unspecified behavior.

To aid in tracking packet distributions, TrafficGenerator has an option to generate logs of packet transmissions using the java.util.logging API. This option is disabled by default and can be toggled using the setLoggingEnabled() method. When logging is enabled, the TrafficGenerator will log its activity to the console if default console logging is enabled (can be disabled), and to any Handlers which are subscribed to the logs. Methods are provided to subscribe/unsubscribe Handlers to/from the logs.

Author:

Kira Lindburg

Field Summary

Fields inherited from class ds.funnel.node.task.Task

AUTOSTART, IGNORENULL, RUNONCE

Method Summary

Modifier and Type	Method and Description
static void	addLoggingHandler(java.util.logging.Handler handler) Adds a log Handler to receive packet transmission log records from all TrafficGenerators.
static TrafficGenerator	getInstance()
boolean	loggingEnabled()
int	prediction() Generates the next predicted interval.
int[]	prediction(int size) Generates an array containing predicted packet transmission times, in terms of number of ms from this instant.
static void	removeLoggingHandler(java.util.logging.Handler handler) Removes the specified log Handler from TrafficGenerator's Logger, if the given Handler is currently subscribed to the logger.
static void	setDefaultConsoleLogging(boolean enable) Toggles future logging of packet transmissions to the default console handler by all TrafficGenerators.
void	setEventDispatcher(EventDispatcher newDispatcher)
void	setLoggingEnabled(boolean enable) Toggles packet transmission logging.
void	setPacketGenerator(PacketGenerator newPacketGenerator)
void	setSizeDistribution(PacketSizeDistribution newSizeDistribution)
void	setStreamIdentifier(java.lang.String newStreamIdentifier)
void	setTimeDistribution(PacketTimeDistribution newTimeDistribution)

Methods inherited from class ds.funnel.node.task.ScheduledTask

cancel, startTaskAsync, startTaskLater, startTaskTimer

Methods inherited from class ds.funnel.node.task.Task

chainTask, getResult, getResult, getResultNow, isCancelled, run, startTask

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getInstance

public static TrafficGenerator getInstance()

setTimeDistribution

public void setTimeDistribution(PacketTimeDistribution newTimeDistribution)

setSizeDistribution

public void setSizeDistribution(PacketSizeDistribution newSizeDistribution)

setPacketGenerator

public void setPacketGenerator(PacketGenerator newPacketGenerator)

setEventDispatcher

public void setEventDispatcher(EventDispatcher newDispatcher)

setStreamIdentifier

public void setStreamIdentifier(java.lang.String newStreamIdentifier)

setLoggingEnabled

public void setLoggingEnabled(boolean enable)

Toggles packet transmission logging. If logging is set to enabled, all future packet transmissions will be logged to the console (if default console logging is enabled) and to any additional handlers which are subscribed to the TrafficGenerator logger.

Parameters:

enable - true if logging should be enabled, false if logging should be disabled

loggingEnabled

public boolean loggingEnabled()

Returns:

a boolean indicating whether packet transmission logging is currently enabled for this traffic generator

addLoggingHandler

public static void addLoggingHandler(java.util.logging.Handler handler)

Adds a log Handler to receive packet transmission log records from all TrafficGenerators.

Parameters:

handler - the logging Handler to add to TrafficGenerator's logger

removeLoggingHandler

public static void removeLoggingHandler(java.util.logging.Handler handler)

Removes the specified log Handler from TrafficGenerator's Logger, if the given Handler is currently subscribed to the logger. As per the Logger's removeHandler method, returns silently if the given Handler is not found or is null.

Parameters:

handler - the Handler to remove from TrafficGenerator's Logger

setDefaultConsoleLogging

public static void setDefaultConsoleLogging(boolean enable)

Toggles future logging of packet transmissions to the default console handler by all TrafficGenerators. The overall status of logging (enabled or disabled) and any other Handlers (including other ConsoleHandlers) subscribed are unaffected by this method.

Parameters:

enable - a boolean indicating whether default console logging should be enabled

prediction

public int prediction()

Generates the next predicted interval.

Returns:

an int containing predicted packet transmission time in numbers of ms after this method was called

prediction

public int[] prediction(int size)

Generates an array containing predicted packet transmission times, in terms of number of ms from this instant.

Parameters:

size - the number of predictions contained in the returned array

Returns:

an array of the specified size, containing predicted packet transmission times in numbers of ms after this method was called