io.prometheus.client

Class Counter

java.lang.Object

io.prometheus.client.Collector

io.prometheus.client.SimpleCollector<Counter.Child>

io.prometheus.client.Counter

All Implemented Interfaces:

Collector.Describable

public class Counter
extends SimpleCollector<Counter.Child>
implements Collector.Describable

Counter metric, to track counts of events or running totals.

Example of Counters include:

• Number of requests processed
• Number of items that were inserted into a queue
• Total amount of data a system has processed

Counters can only go up (and be reset), if your use case can go down you should use a Gauge instead. Use the rate() function in Prometheus to calculate the rate of increase of a Counter. By convention, the names of Counters are suffixed by _total.

An example Counter:

 
   class YourClass {
     static final Counter requests = Counter.build()
         .name("requests_total").help("Total requests.").register();
     static final Counter failedRequests = Counter.build()
         .name("requests_failed_total").help("Total failed requests.").register();

     void processRequest() {
        requests.inc();
        try {
          // Your code here.
        } catch (Exception e) {
          failedRequests.inc();
          throw e;
        }
     }
   }
 
 

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

 
   class YourClass {
     static final Counter requests = Counter.build()
         .name("requests_total").help("Total requests.")
         .labelNames("method").register();

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

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	Counter.Builder
static class	Counter.Child The value of a single Counter.

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

Collector.Describable, 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

Modifier and Type	Method and Description
static Counter.Builder	build() Return a Builder to allow configuration of a new Counter.
static Counter.Builder	build(String name, String help) Return a Builder to allow configuration of a new Counter.
List<Collector.MetricFamilySamples>	collect() Return all of the metrics of this Collector.
List<Collector.MetricFamilySamples>	describe() Provide a list of metric families this Collector is expected to return.
double	get() Get the value of the counter.
void	inc() Increment the counter with no labels by 1.
void	inc(double amt) Increment the counter with no labels by the given amount.
protected Counter.Child	newChild() Return a new child, workaround for Java generics limitations.

Methods inherited from class io.prometheus.client.SimpleCollector

clear, familySamplesList, initializeNoLabelsChild, labels, remove, setChild

Methods inherited from class io.prometheus.client.Collector

checkMetricLabelName, checkMetricName, doubleToGoString, register, register, sanitizeMetricName

Methods inherited from class java.lang.Object

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

Method Detail

build

public static Counter.Builder build(String name,
                                    String help)

Return a Builder to allow configuration of a new Counter. Ensures required fields are provided.

Parameters:

name - The name of the metric

help - The help string of the metric

build

public static Counter.Builder build()

Return a Builder to allow configuration of a new Counter.

newChild

protected Counter.Child newChild()

Description copied from class: SimpleCollector

Return a new child, workaround for Java generics limitations.

Specified by:

newChild in class SimpleCollector<Counter.Child>

inc

public void inc()

Increment the counter with no labels by 1.

inc

public void inc(double amt)

Increment the counter with no labels by the given amount.

Throws:

IllegalArgumentException - If amt is negative.

get

public double get()

Get the value of the counter.

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

describe

public List<Collector.MetricFamilySamples> describe()

Description copied from interface: Collector.Describable

Provide a list of metric families this Collector is expected to return. These should exclude the samples. This is used by the registry to detect collisions and duplicate registrations. Usually custom collectors do not have to implement Describable. If Describable is not implemented and the CollectorRegistry was created with auto describe enabled (which is the case for the default registry) then collect will be called at registration time instead of describe. If this could cause problems, either implement a proper describe, or if that's not practical have describe return an empty list.

Specified by:

describe in interface Collector.Describable