io.prometheus.client

Class Gauge

java.lang.Object

io.prometheus.client.Collector

io.prometheus.client.SimpleCollector<Gauge.Child,Gauge>

io.prometheus.client.Gauge

public class Gauge
extends SimpleCollector<Gauge.Child,Gauge>

Gauge metric, to report instantaneous values.

Examples of Gauges include:

• Inprogress requests
• Number of items in a queue
• Free memory
• Total memory
• Temperature

Gauges can go both up and down.

An example Gauge:

 class YourClass {
     static final Gauge inprogressRequests = Gauge.build()
         .name("inprogress_requests").help("Inprogress requests.").register();

     void processRequest() {
        inprogressRequest.inc();
        // Your code here.
        inprogressRequest.dec();
     }
   }
 
 

You can also use labels to track different types of metric:

 class YourClass {
     static final Gauge inprogressRequests = Gauge.build()
         .name("inprogress_requests").help("Inprogress requests.")
         .labelNames("method").register();

     void processGetRequest() {
        inprogressRequests.labels("get").inc();
        // Your code here.
        inprogressRequests.labels("get").dec();
     }
     void processPostRequest() {
        inprogressRequests.labels("post").inc();
        // Your code here.
        inprogressRequests.labels("post").dec();
     }
   }
 
 

These can be aggregated and processed together much more easily in the Prometheus server than individual metrics for each labelset.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Gauge.Builder
static class	Gauge.Child The value of a single Gauge.
static class	Gauge.Timer Represents an event being timed.

Nested classes/interfaces inherited from class io.prometheus.client.Collector

Collector.MetricFamilySamples, Collector.Type

Field Summary

Fields inherited from class io.prometheus.client.SimpleCollector

children, fullname, help, labelNames, noLabelsChild

Fields inherited from class io.prometheus.client.Collector

MILLISECONDS_PER_SECOND, NANOSECONDS_PER_SECOND

Method Summary

Methods

Modifier and Type	Method and Description
static Gauge.Builder	build() Return a Builder to allow configuration of a new Gauge.
List<Collector.MetricFamilySamples>	collect() Return all of the metrics of this Collector.
void	dec() Increment the gauge with no labels by 1.
void	dec(double amt) Decrement the gauge with no labels by the given amount.
void	inc() Increment the gauge with no labels by 1.
void	inc(double amt) Increment the gauge with no labels by the given amount.
protected Gauge.Child	newChild() Return a new child, workaround for Java generics limitations.
void	set(double val) Set the gauge with no labels to the given value.
void	setToCurrentTime() Set the gauge with no labels to the current unixtime.
Gauge.Timer	startTimer() Start a timer to track a duration, for the gauge with no labels.

Methods inherited from class io.prometheus.client.SimpleCollector

clear, labels, remove, setChild

Methods inherited from class io.prometheus.client.Collector

register, register

Methods inherited from class java.lang.Object

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

Method Detail

build

public static Gauge.Builder build()

Return a Builder to allow configuration of a new Gauge.

newChild

protected Gauge.Child newChild()

Description copied from class: SimpleCollector

Return a new child, workaround for Java generics limitations.

Specified by:

newChild in class SimpleCollector<Gauge.Child,Gauge>

inc

public void inc()

Increment the gauge with no labels by 1.

inc

public void inc(double amt)

Increment the gauge with no labels by the given amount.

dec

public void dec()

Increment the gauge with no labels by 1.

dec

public void dec(double amt)

Decrement the gauge with no labels by the given amount.

set

public void set(double val)

Set the gauge with no labels to the given value.

setToCurrentTime

public void setToCurrentTime()

Set the gauge with no labels to the current unixtime.

startTimer

public Gauge.Timer startTimer()

Start a timer to track a duration, for the gauge with no labels.

This is primarily useful for tracking the durations of major steps of batch jobs, which are then pushed with PushGateway. For tracking other durations/latencies you should usually use a Summary.

Call Gauge.Timer.setDuration() at the end of what you want to measure the duration of.

collect

public List<Collector.MetricFamilySamples> collect()

Description copied from class: Collector

Return all of the metrics of this Collector.

Specified by:

collect in class Collector