Package io.prometheus.metrics.core.metrics

Class Gauge

java.lang.Object

io.prometheus.metrics.core.metrics.Metric

io.prometheus.metrics.core.metrics.MetricWithFixedMetadata

io.prometheus.metrics.core.metrics.StatefulMetric<GaugeDataPoint,Gauge.DataPoint>

io.prometheus.metrics.core.metrics.Gauge

All Implemented Interfaces:

DataPoint, GaugeDataPoint, TimerApi, Collector

public class Gauge
extends StatefulMetric<GaugeDataPoint,Gauge.DataPoint>
implements GaugeDataPoint

Gauge metric.

Example usage:

 Gauge currentActiveUsers = Gauge.builder()
     .name("current_active_users")
     .help("Number of users that are currently active")
     .labelNames("region")
     .register();

 public void login(String region) {
     currentActiveUsers.labelValues(region).inc();
     // perform login
 }

 public void logout(String region) {
     currentActiveUsers.labelValues(region).dec();
     // perform logout
 }
 

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Gauge.Builder
(package private) static class	Gauge.DataPoint

Field Summary

Fields

Modifier and Type	Field	Description
private final ExemplarSamplerConfig	exemplarSamplerConfig

Fields inherited from class io.prometheus.metrics.core.metrics.MetricWithFixedMetadata

labelNames

Fields inherited from class io.prometheus.metrics.core.metrics.Metric

constLabels

Constructor Summary

Constructors

Modifier	Constructor	Description
private	Gauge(Gauge.Builder builder, PrometheusProperties prometheusProperties)

Method Summary

Modifier and Type	Method	Description
static Gauge.Builder	builder()
static Gauge.Builder	builder(PrometheusProperties config)
GaugeSnapshot	collect()	Called when the Prometheus server scrapes metrics.
protected GaugeSnapshot	collect(List<Labels> labels, List<Gauge.DataPoint> metricData)	labels and metricData have the same size.
double	get()	Get the current value.
MetricType	getMetricType()	Returns the metric type for registration-time validation.
void	inc(double amount)	Add amount.
void	incWithExemplar(double amount, Labels labels)	Add amount, and create a custom exemplar with the given labels.
protected Gauge.DataPoint	newDataPoint()
void	set(double value)	Set the gauge to value.
void	setWithExemplar(double value, Labels labels)	Set the gauge to value, and create a custom exemplar with the given labels.

Methods inherited from class io.prometheus.metrics.core.metrics.StatefulMetric

clear, getConfigProperty, getMetricProperties, getNoLabels, initLabelValues, labelValues, remove, removeIf

Methods inherited from class io.prometheus.metrics.core.metrics.MetricWithFixedMetadata

getLabelNames, getMetadata, getPrometheusName

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.prometheus.metrics.model.registry.Collector

collect, collect, collect

Methods inherited from interface io.prometheus.metrics.core.datapoints.GaugeDataPoint

dec, dec, decWithExemplar, decWithExemplar, inc, incWithExemplar, startTimer

Methods inherited from interface io.prometheus.metrics.core.datapoints.TimerApi

time, time, timeChecked

Field Details

exemplarSamplerConfig

private final ExemplarSamplerConfig exemplarSamplerConfig

Constructor Details

Gauge

private Gauge(Gauge.Builder builder,
 PrometheusProperties prometheusProperties)

Method Details

inc

public void inc(double amount)

Description copied from interface: GaugeDataPoint

Add amount.

Specified by:

inc in interface GaugeDataPoint

get

public double get()

Description copied from interface: GaugeDataPoint

Get the current value.

Specified by:

get in interface GaugeDataPoint

incWithExemplar

public void incWithExemplar(double amount,
 Labels labels)

Description copied from interface: GaugeDataPoint

Add amount, and create a custom exemplar with the given labels.

Specified by:

incWithExemplar in interface GaugeDataPoint

set

public void set(double value)

Description copied from interface: GaugeDataPoint

Set the gauge to value.

Specified by:

set in interface GaugeDataPoint

setWithExemplar

public void setWithExemplar(double value,
 Labels labels)

Description copied from interface: GaugeDataPoint

Set the gauge to value, and create a custom exemplar with the given labels.

Specified by:

setWithExemplar in interface GaugeDataPoint

collect

public GaugeSnapshot collect()

Description copied from interface: Collector

Called when the Prometheus server scrapes metrics.

Specified by:

collect in interface Collector

Overrides:

collect in class StatefulMetric<GaugeDataPoint,Gauge.DataPoint>

collect

protected GaugeSnapshot collect(List<Labels> labels,
 List<Gauge.DataPoint> metricData)

Description copied from class: StatefulMetric

labels and metricData have the same size. labels.get(i) are the labels for metricData.get(i).

Specified by:

collect in class StatefulMetric<GaugeDataPoint,Gauge.DataPoint>

getMetricType

public MetricType getMetricType()

Description copied from interface: Collector

Returns the metric type for registration-time validation.

This is used to prevent different metric types (e.g., Counter and Gauge) from sharing the same name. Returning null means type validation is skipped for this collector.

Validation is performed only at registration time. If this method returns null, no type validation is performed for this collector, and duplicate or conflicting metrics may result in invalid exposition output.

Specified by:

getMetricType in interface Collector

Returns:

the metric type, or null to skip validation

newDataPoint

protected Gauge.DataPoint newDataPoint()

Specified by:

newDataPoint in class StatefulMetric<GaugeDataPoint,Gauge.DataPoint>

builder

public static Gauge.Builder builder()

builder

public static Gauge.Builder builder(PrometheusProperties config)