org.apache.commons.performance
Class ClientThread

java.lang.Object
  org.apache.commons.performance.ClientThread

All Implemented Interfaces:

java.lang.Runnable

Direct Known Subclasses:

DBCPClientThread, HttpClientThread, PoolClientThread

public abstract class ClientThread
extends java.lang.Object
implements java.lang.Runnable

Base for performance / load test clients. The run method executes init, then setup-execute-cleanup in a loop, gathering performance statistics, with time between executions based on configuration parameters. See nextDelay() for details on inter-arrival time computation.

Subclasses must implement execute, which is the basic client request action that is executed, and timed, repeatedly. If per-request setup is required, and you do not want the time associated with this setup to be included in the reported timings, implement setUp and put the setup code there. Similarly for cleanUp. Initialization code that needs to be executed once only, before any requests are initiated, should be put into init.

Field Summary

protected int	cycleState Cycle state
protected java.lang.String	cycleType Cycle type
protected java.lang.String	delayType Delay type - determines how next start times are computed
protected long	iterations Number of iterations
protected double	lastMean Last mean delay
protected java.util.logging.Logger	logger Logger shared by client threads
protected long	maxDelay Maxiimum mean time between requests
protected long	minDelay Minimum mean time between requests
protected static int	PEAK_LOAD
protected long	peakPeriod Peak length for cyclic mean delay
protected long	periodStart Start time of current period
protected static int	RAMPING_DOWN
protected static int	RAMPING_UP Cycle state constants
protected long	rampPeriod Ramp length for cyclic mean delay
protected java.lang.String	rampType Ramp type
protected org.apache.commons.math.random.RandomData	randomData Random data generator
protected double	sigma Standard deviation of delay distribution
protected long	startTime Start time of run
protected Statistics	stats Statistics container
protected static int	TROUGH_LOAD
protected long	troughPeriod Trough length for cyclic mean delay

Constructor Summary

ClientThread(long iterations, long minDelay, long maxDelay, double sigma, java.lang.String delayType, long rampPeriod, long peakPeriod, long troughPeriod, java.lang.String cycleType, java.lang.String rampType, java.util.logging.Logger logger, Statistics stats)
Create a client thread.

Method Summary

protected void	adjustState(long currentTime) Adjusts cycleState, periodStart and lastMean if a cycle state transition needs to happen.
protected void	cleanUp() Executed in finally block of iteration try-catch
protected double	computeCyclicDelay(long currentTime, double min, double max)
abstract void	execute() Core iteration code.
protected void	finalize() Executed once after the run finishes
protected void	init() Executed once at the beginning of the run
protected long	nextDelay() Computes the next interarrival time (time to wait between requests) based on configured values for min/max delay, delay type, cycle type, ramp type and period.
void	run()
protected void	setUp() Executed at the beginning of each iteration

Methods inherited from class java.lang.Object

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

Field Detail

minDelay

protected long minDelay

Minimum mean time between requests

maxDelay

protected long maxDelay

Maxiimum mean time between requests

sigma

protected double sigma

Standard deviation of delay distribution

delayType

protected java.lang.String delayType

Delay type - determines how next start times are computed

rampPeriod

protected long rampPeriod

Ramp length for cyclic mean delay

peakPeriod

protected long peakPeriod

Peak length for cyclic mean delay

troughPeriod

protected long troughPeriod

Trough length for cyclic mean delay

cycleType

protected java.lang.String cycleType

Cycle type

rampType

protected java.lang.String rampType

Ramp type

iterations

protected long iterations

Number of iterations

startTime

protected long startTime

Start time of run

periodStart

protected long periodStart

Start time of current period

lastMean

protected double lastMean

Last mean delay

RAMPING_UP

protected static final int RAMPING_UP

Cycle state constants

See Also:

Constant Field Values

RAMPING_DOWN

protected static final int RAMPING_DOWN

See Also:

Constant Field Values

PEAK_LOAD

protected static final int PEAK_LOAD

See Also:

Constant Field Values

TROUGH_LOAD

protected static final int TROUGH_LOAD

See Also:

Constant Field Values

cycleState

protected int cycleState

Cycle state

randomData

protected org.apache.commons.math.random.RandomData randomData

Random data generator

stats

protected Statistics stats

Statistics container

logger

protected java.util.logging.Logger logger

Logger shared by client threads

Constructor Detail

ClientThread

public ClientThread(long iterations,
                    long minDelay,
                    long maxDelay,
                    double sigma,
                    java.lang.String delayType,
                    long rampPeriod,
                    long peakPeriod,
                    long troughPeriod,
                    java.lang.String cycleType,
                    java.lang.String rampType,
                    java.util.logging.Logger logger,
                    Statistics stats)

Create a client thread.

Parameters:

iterations - number of iterations

minDelay - minumum mean time between client requests

maxDelay - maximum mean time between client requests

delayType - distribution of time between client requests

rampPeriod - ramp period of cycle for cyclic load

peakOeriod - peak period of cycle for cyclic load

troughPeriod - trough period of cycle for cyclic load

cycleType - type of cycle for mean delay

rampType - type of ramp (linear or random jumps)

logger - common logger shared by all clients

statsList - List of SummaryStatistics to add results to

Method Detail

run

public void run()

Specified by:

run in interface java.lang.Runnable

init

protected void init()
             throws java.lang.Exception

Executed once at the beginning of the run

Throws:

java.lang.Exception

setUp

protected void setUp()
              throws java.lang.Exception

Executed at the beginning of each iteration

Throws:

java.lang.Exception

cleanUp

protected void cleanUp()
                throws java.lang.Exception

Executed in finally block of iteration try-catch

Throws:

java.lang.Exception

finalize

protected void finalize()
                 throws java.lang.Exception

Executed once after the run finishes

Overrides:

finalize in class java.lang.Object

Throws:

java.lang.Exception

execute

public abstract void execute()
                      throws java.lang.Exception

Core iteration code. Timings are based on this, so keep it tight.

Throws:

java.lang.Exception

nextDelay

protected long nextDelay()
                  throws ConfigurationException

Computes the next interarrival time (time to wait between requests) based on configured values for min/max delay, delay type, cycle type, ramp type and period. Currently supports constant (always returning minDelay delay time), Poisson and Gaussian distributed random time delays, linear and random ramps, and oscillating / non-oscillating cycle types.

loadType determines whether returned times are deterministic or random. If loadType is not "constant", a random value with the specified distribution and mean determined by the other parameters is returned. For "gaussian" loadType, sigma is used as used as the standard deviation.

cycleType determines how the returned times vary over time. "oscillating", means times ramp up and down between minDelay and maxDelay. Ramp type is controlled by rampType. Linear rampType means the means increase or decrease linearly over the time of the period. Random makes random jumps up or down toward the next peak or trough. "None" for rampType under oscillating cycleType makes the means alternate between peak (minDelay) and trough (maxDelay) with no ramp between.

Oscillating loads cycle through RAMPING_UP, PEAK_LOAD, RAMPING_DOWN and TROUGH_LOAD states, with the amount of time spent in each state determined by rampPeriod (time spent increasing on the way up and decreasing on the way down), peakPeriod (time spent at peak load, i.e., minDelay mean delay) and troughPeriod (time spent at minimum load, i.e., maxDelay mean delay). All times are specified in milliseconds.

Examples:

1. Given

    delayType = "constant"
    minDelay = 250
    maxDelay = 500
    cycleType = "oscillating"
    rampType = "linear" 
    rampPeriod = 10000
    peakPeriod = 20000
    troughPeriod = 30000

   load will start at one request every 500 ms, which is "trough load." Load then ramps up linearly over the next 10 seconds unil it reaches one request per 250 milliseconds, which is "peak load." Peak load is sustained for 20 seconds and then load ramps back down, again taking 10 seconds to get down to "trough load," which is sustained for 30 seconds. The cycle then repeats.

2.  delayType = "gaussian"
    minDelay = 250
    maxDelay = 500
    cycleType = "oscillating"
    rampType = "linear" 
    rampPeriod = 10000
    peakPeriod = 20000
    troughPeriod = 30000
    sigma = 100 

   produces a load pattern similar to example 1, but in this case the computed delay value is fed into a gaussian random number generator as the mean and 100 as the standard deviation - i.e., nextDelay returns random, gaussian distributed values with means moving according to the cyclic pattern in example 1.

3.  delayType = "constant"
    minDelay = 250
    maxDelay = 500
    cycleType = "none"
    rampType = "linear" 
    rampPeriod = 10000

   produces a load pattern that increases linearly from one request every 500ms to one request every 250ms and then stays constant at that level until the run is over. Other parameters are ignored in this case.

4.  delayType = "poisson"
    minDelay = 250
    maxDelay = 500
    cycleType = "none"
    rampType = "none" 
    

   produces inter-arrival times that are poisson distributed with mean 250ms. Note that when rampType is "none," the value of minDelay is used as the (constant) mean delay.

Returns:

next value for delay

Throws:

ConfigurationException

adjustState

protected void adjustState(long currentTime)

Adjusts cycleState, periodStart and lastMean if a cycle state transition needs to happen.

Parameters:

currentTime - current time

computeCyclicDelay

protected double computeCyclicDelay(long currentTime,
                                    double min,
                                    double max)