71 Gauge.md

title	excerpt
Gauge	Gauge is an object for representing a custom metric holding only the latest value added.

Gauge is an object for representing a custom metric holding only the latest value added. It is one of the four custom metrics.

Parameter	Type	Description
name	string	The name of the custom metric.
isTime	boolean	A boolean indicating whether the values added to the metric are time values or just untyped values.

Method	Description
Gauge.add(value, [tags])	Add a value to the gauge metric. Only the latest value added will be kept.

Gauge usage in Thresholds

When gauge is used in a threshold expression, the variable must be called value (lower case). For example:

• value < 200
• value > 1

Examples

<CodeGroup labels={["gauge-metric.js"]} lineNumbers={[true]}>

import { Gauge } from 'k6/metrics';

const myGauge = new Gauge('my_gauge');

export default function () {
  myGauge.add(3);
  myGauge.add(1);
  myGauge.add(2, { tag1: 'value', tag2: 'value2' });
}

<CodeGroup labels={["gauge-threshold.js"]} lineNumbers={[true]}>

import http from 'k6/http';
import { sleep } from 'k6';
import { Gauge } from 'k6/metrics';

const GaugeContentSize = new Gauge('ContentSize');

export const options = {
  thresholds: {
    ContentSize: ['value<4000'],
  },
};

export default function () {
  const res = http.get('https://test-api.k6.io/public/crocodiles/1/');
  GaugeContentSize.add(res.body.length);
  sleep(1);
}