org.perfcake.reporting.reporter

Class ResponseTimeHistogramReporter

java.lang.Object

org.perfcake.reporting.reporter.AbstractReporter

org.perfcake.reporting.reporter.ResponseTimeHistogramReporter

All Implemented Interfaces:

Reporter

public class ResponseTimeHistogramReporter
extends AbstractReporter

Reports response time in milliseconds using HDR Histogram that can computationally correct the Coordinated omission problem.

The following paragraphs are based on the HDR Histogram documentation.

This reporter depends on the features introduced by HDR Histogram to correct the coordinated omission. To compensate for the loss of sampled values when a recorded value is larger than the expected, interval between value samples, HDR Histogram will auto-generate an additional series of decreasingly-smaller value records. The values go down to the expectedValue in case of the ResponseTimeHistogramReporter.Correction.USER correction mode, or down to the average response time in case of the ResponseTimeHistogramReporter.Correction.AUTO correction mode.

The reporter could be configured to track the counts of observed response times in milliseconds between 0 and 3,600,000 (maxExpectedValue) while maintaining a value precision of 3 (precision) significant digits across that range. Value quantization within the range will thus be no larger than 1/1,000th (or 0.1%) of any value. This example reporter could be used to track and analyze the counts of observed response times ranging between 1 millisecond and 1 hour in magnitude, while maintaining a value resolution of 1 millisecond (or better) up to one second, and a resolution of 1 second (or better) up to 1,000 seconds. At its maximum tracked value (1 hour), it would still maintain a resolution of 3.6 seconds (or better).

Author:

Martin Večeřa

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ResponseTimeHistogramReporter.Correction Correction mode can be switched off (no correction), automatic or user specified.

Constructor Summary

Constructors

Constructor and Description
ResponseTimeHistogramReporter()

Method Summary

Modifier and Type	Method and Description
ResponseTimeHistogramReporter.Correction	getCorrectionMode() Gets the expectedValue of coordinated omission in the resulting histogram.
int	getDetail() Gets the detail level of the result (the number of iteration steps per half-distance to 100%).
long	getExpectedValue() Gets the expectedValue value for the coordinated omission when the ResponseTimeHistogramReporter.Correction.USER mode is set.
long	getMaxExpectedValue() Gets the maximum expected value to better organize the data in the histogram.
int	getPrecision() Gets the precision as the number of significant digits that are recognized by this reporter.
String	getPrefix() Gets the prefix of percentile values in the result map.
boolean	isFilter() Gets the state of results filter.
void	publishResult(PeriodType periodType, Destination destination) Publishes results to the destination.
ResponseTimeHistogramReporter	setCorrectionMode(ResponseTimeHistogramReporter.Correction correctionMode) Sets the expectedValue of coordinated omission in the resulting histogram.
ResponseTimeHistogramReporter	setDetail(int detail) Sets the detail level of the result (the number of iteration steps per half-distance to 100%).
ResponseTimeHistogramReporter	setExpectedValue(long expectedValue) Sets the expectedValue value for the coordinated omission when the ResponseTimeHistogramReporter.Correction.USER mode is set.
ResponseTimeHistogramReporter	setFilter(boolean filter) Sets the state of results filter.
ResponseTimeHistogramReporter	setMaxExpectedValue(long maxExpectedValue) Sets the maximum expected value to better organize the data in the histogram.
ResponseTimeHistogramReporter	setPrecision(int precision) Sets the precision as the number of significant digits that are recognized by this reporter.
ResponseTimeHistogramReporter	setPrefix(String prefix) Sets the prefix of percentile values in the result map.

Methods inherited from class org.perfcake.reporting.reporter.AbstractReporter

getDestinations, getReportingPeriods, newMeasurement, registerDestination, registerDestination, report, reset, setReportManager, setRunInfo, start, stop, unregisterDestination

Methods inherited from class java.lang.Object

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

Constructor Detail

ResponseTimeHistogramReporter

public ResponseTimeHistogramReporter()

Method Detail

publishResult

public void publishResult(PeriodType periodType,
                          Destination destination)
                   throws ReportingException

Description copied from interface: Reporter

Publishes results to the destination. This method is called only when the results should be published.

Parameters:

periodType - A period type that caused the invocation of this method.

destination - A destination to which the result should be reported.

Throws:

ReportingException - When it was not possible to publish results to the given destination.

getPrecision

public int getPrecision()

Gets the precision as the number of significant digits that are recognized by this reporter.

Returns:

The number of significant digits that are recognized by this reporter.

setPrecision

public ResponseTimeHistogramReporter setPrecision(int precision)

Sets the precision as the number of significant digits that are recognized by this reporter. Must be in interval 0 - 5. Default value is 2.

Parameters:

precision - The number of significant digits that are recognized by this reporter.

Returns:

Instance of this to support fluent API.

getCorrectionMode

public ResponseTimeHistogramReporter.Correction getCorrectionMode()

Gets the expectedValue of coordinated omission in the resulting histogram. ResponseTimeHistogramReporter.Correction.AUTO is the default value and this means that the histogram is corrected by the average measured value. In case of the ResponseTimeHistogramReporter.Correction.USER mode, the user specifies the expected response time manually for correct computation of the histogram. When the ResponseTimeHistogramReporter.Correction.OFF mode is used, no correction is performed.

Returns:

The expectedValue mode.

setCorrectionMode

public ResponseTimeHistogramReporter setCorrectionMode(ResponseTimeHistogramReporter.Correction correctionMode)

Sets the expectedValue of coordinated omission in the resulting histogram. ResponseTimeHistogramReporter.Correction.AUTO is the default value and this means that the histogram is corrected by the average measured value. In case of the ResponseTimeHistogramReporter.Correction.USER mode, the user specifies the expected response time manually for correct computation of the histogram. When the ResponseTimeHistogramReporter.Correction.OFF mode is used, no correction is performed.

Parameters:

correctionMode - The expectedValue mode to be used.

Returns:

Instance of this to support fluent API.

getExpectedValue

public long getExpectedValue()

Gets the expectedValue value for the coordinated omission when the ResponseTimeHistogramReporter.Correction.USER mode is set.

Returns:

The expectedValue value.

setExpectedValue

public ResponseTimeHistogramReporter setExpectedValue(long expectedValue)

Sets the expectedValue value for the coordinated omission when the ResponseTimeHistogramReporter.Correction.USER mode is set.

Parameters:

expectedValue - The expectedValue value.

Returns:

Instance of this to support fluent API.

getPrefix

public String getPrefix()

Gets the prefix of percentile values in the result map.

Returns:

The percentile value prefix.

setPrefix

public ResponseTimeHistogramReporter setPrefix(String prefix)

Sets the prefix of percentile values in the result map.

Parameters:

prefix - The percentile value prefix.

Returns:

Instance of this to support fluent API.

getDetail

public int getDetail()

Gets the detail level of the result (the number of iteration steps per half-distance to 100%). Must be greater than 0. The default value is 2.

Returns:

The detail level.

setDetail

public ResponseTimeHistogramReporter setDetail(int detail)

Sets the detail level of the result (the number of iteration steps per half-distance to 100%). Must be greater than 0. The default value is 2.

Parameters:

detail - The detail level.

Returns:

Instance of this to support fluent API.

getMaxExpectedValue

public long getMaxExpectedValue()

Gets the maximum expected value to better organize the data in the histogram.

Returns:

The maximal expected value. -1 means that this optimization off.

setMaxExpectedValue

public ResponseTimeHistogramReporter setMaxExpectedValue(long maxExpectedValue)

Sets the maximum expected value to better organize the data in the histogram. The response time reported must never exceed this value, otherwise the result will be skipped, an error reported and the output will be invalid. -1 turns the optimization off. It is valuable to set some reasonable number like 3_600_000 which equals to the resolution from 1 millisecond to 1 hour.

Parameters:

maxExpectedValue - The maximal expected value. -1 to turn this optimization off. -1 is the default value.

Returns:

Instance of this to support fluent API.

isFilter

public boolean isFilter()

Gets the state of results filter. When true, the results with the same value are collapsed.

Returns:

The state of results filter. When true, the results with the same value are collapsed.

setFilter

public ResponseTimeHistogramReporter setFilter(boolean filter)

Sets the state of results filter. When true, the results with the same value are collapsed.

Parameters:

filter - The state of results filter. When true, the results with the same value are collapsed.

Returns:

Instance of this to support fluent API.