Package io.prometheus.client

Class Histogram.Child

java.lang.Object

io.prometheus.client.Histogram.Child

Enclosing class:

Histogram

public static class Histogram.Child
extends Object

The value of a single Histogram.

Warning: References to a Child become invalid after using SimpleCollector.remove(java.lang.String...) or SimpleCollector.clear().

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Histogram.Child.Value

Method Summary

Modifier and Type	Method	Description
Histogram.Child.Value	get()	Get the value of the Histogram.
void	observe(double amt)	Observe the given amount.
void	observeWithExemplar(double amt, String... exemplarLabels)	Like observe(double), but additionally creates an exemplar.
void	observeWithExemplar(double amt, Map<String,String> exemplarLabels)	Like observeWithExemplar(double, String...), but the exemplar labels are passed as a Map.
Histogram.Timer	startTimer()	Start a timer to track a duration.
double	time(Runnable timeable)	Executes runnable code (e.g.
<E> E	time(Callable<E> timeable)	Executes callable code (e.g.
double	timeWithExemplar(Runnable timeable, String... exemplarLabels)	Like time(Runnable), but additionally create an exemplar.
double	timeWithExemplar(Runnable timeable, Map<String,String> exemplarLabels)	Like time(Runnable), but additionally create an exemplar.
<E> E	timeWithExemplar(Callable<E> timeable, String... exemplarLabels)	Like time(Callable), but additionally create an exemplar.
<E> E	timeWithExemplar(Callable<E> timeable, Map<String,String> exemplarLabels)	Like time(Callable), but additionally create an exemplar.

Methods inherited from class java.lang.Object

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

Method Detail

time

public double time(Runnable timeable)

Executes runnable code (e.g. a Java 8 Lambda) and observes a duration of how long it took to run.

Parameters:

timeable - Code that is being timed

Returns:

Measured duration in seconds for timeable to complete.

timeWithExemplar

public double timeWithExemplar(Runnable timeable,
                               String... exemplarLabels)

Like time(Runnable), but additionally create an exemplar.

See observeWithExemplar(double, String...) for documentation on the exemplarLabels parameter.

timeWithExemplar

public double timeWithExemplar(Runnable timeable,
                               Map<String,String> exemplarLabels)

Like time(Runnable), but additionally create an exemplar.

See observeWithExemplar(double, Map) for documentation on the exemplarLabels parameter.

time

public <E> E time(Callable<E> timeable)

Executes callable code (e.g. a Java 8 Lambda) and observes a duration of how long it took to run.

Parameters:

timeable - Code that is being timed

Returns:

Result returned by callable.

timeWithExemplar

public <E> E timeWithExemplar(Callable<E> timeable,
                              String... exemplarLabels)

Like time(Callable), but additionally create an exemplar.

See observeWithExemplar(double, String...) for documentation on the exemplarLabels parameter.

timeWithExemplar

public <E> E timeWithExemplar(Callable<E> timeable,
                              Map<String,String> exemplarLabels)

Like time(Callable), but additionally create an exemplar.

See observeWithExemplar(double, Map) for documentation on the exemplarLabels parameter.

observe

public void observe(double amt)

Observe the given amount.

Parameters:

amt - in most cases amt should be >= 0. Negative values are supported, but you should read https://prometheus.io/docs/practices/histograms/#count-and-sum-of-observations for implications and alternatives.

observeWithExemplar

public void observeWithExemplar(double amt,
                                String... exemplarLabels)

Like observe(double), but additionally creates an exemplar.

This exemplar takes precedence over any exemplar returned by the HistogramExemplarSampler configured in ExemplarConfig.

The exemplar will have amt as the value, System.currentTimeMillis() as the timestamp, and the specified labels.

Parameters:

amt - same as in observe(double) (double)}

exemplarLabels - list of name/value pairs, as documented in Exemplar(double, String...). A commonly used name is "trace_id". Calling observeWithExemplar(amt) means that an exemplar without labels is created. Calling observeWithExemplar(amt, (String[]) null) is equivalent to calling observe(amt).

observeWithExemplar

public void observeWithExemplar(double amt,
                                Map<String,String> exemplarLabels)

Like observeWithExemplar(double, String...), but the exemplar labels are passed as a Map.

startTimer

public Histogram.Timer startTimer()

Start a timer to track a duration.

Call Histogram.Timer.observeDuration() at the end of what you want to measure the duration of.

get

public Histogram.Child.Value get()

Get the value of the Histogram.

Warning: The definition of Histogram.Child.Value is subject to change.