This topic includes instructions on how to send custom metrics to Logz.io from your Node.js application.

The included example uses the OpenTelemetry JS SDK and its based on OpenTelemetry exporter collector proto.

Before you begin, you'll need: Node 8 or higher

Quick start

Set the variables in the following code snippet:

|Environment variable|Description| |---|---| |url| The Logz.io Listener URL for for your region, configured to use port 8052 for http traffic, or port 8053 for https traffic. | |token| Your Logz.io Prometheus Metrics account token. |

const { MeterProvider } = require('@opentelemetry/metrics');
const { RemoteWriteMetricExporter } =  require('yotam-js-metrics-test');

const collectorOptions = {
    url: '<<url>>',
    token: '<<token>>',
};
// Initialize the exporter
const metricExporter = new RemoteWriteMetricExporter(collectorOptions);

// Initialize the meter provider
const meter = new MeterProvider({
    exporter: metricExporter,
    interval: 15000, // Push interval in seconds
}).getMeter('example-exporter');

// Create your first counter metric
const requestCounter = meter.createCounter('Counter', {
    description: 'Example of a Counter', 
});
// Define some labels for your metrics
const labels = { environment: 'prod' };
// Record some value
requestCounter.bind(labels).add(1);
// In logzio Metrics you will see the following metric:
// Counter_total{environment: 'prod'} 1.0

Types of metric instruments

For more information, see the OpenTelemetry documentation.

| Name | Behavior | | ---- | ---------- | | Counter | Metric value can only go up or be reset to 0, calculated per counter.Add(context,value,labels) request. | | UpDownCounter | Metric value can arbitrarily increment or decrement, calculated per updowncounter.Add(context,value,labels) request. | | ValueRecorder | Metric values captured by the valuerecorder.Record(context,value,labels) function, calculated per request. | | SumObserver | Metric value can only go up or be reset to 0, calculated per push interval.| | UpDownSumObserver | Metric value can arbitrarily increment or decrement, calculated per push interval.| | ValueObserver | Metric values captured by the callback function, calculated per push interval.|

More examples

First Initialize the exporter and meter provider:

const { MeterProvider } = require('@opentelemetry/metrics');
const { RemoteWriteMetricExporter } =  require('yotam-js-metrics-test');

const collectorOptions = {
    url: '<<url>>',
    token: '<<token>>',
};
// Initialize the exporter
const metricExporter = new RemoteWriteMetricExporter(collectorOptions);

// Initialize the meter provider
const meter = new MeterProvider({
    exporter: metricExporter,
    interval: 15000, // Push interval in seconds
}).getMeter('example-exporter');

Then create different types of metrics

UpDownCounter:

// Create UpDownCounter metric
const upDownCounter = meter.createUpDownCounter('UpDownCounter', {
    description: 'Example of a UpDownCounter',
});
// Define some labels for your metrics
const labels = { environment: 'prod' };
// Record some values
upDownCounter.bind(labels);
upDownCounter.add(5);
upDownCounter.add(-1);
// In logzio you will see the following metric:
// UpDownCounter{environment: 'prod'} 4.0

ValueRecorder:

// Create ValueRecorder metric
const recorder = meter.createValueRecorder('test_value_recorder', {
    description: 'Example of a ValueRecorder',
});
// Define some labels for your metrics
const labels = { environment: 'prod' };
// Record some values
recorder.bind(labels);
recorder.record(30);
recorder.record(20);
// In logzio you will see the following metrics:
// test_value_recorder_sum{environment: 'prod'} 50.0
// test_value_recorder_count{environment: 'prod'} 2.0
// test_value_recorder_avg{environment: 'prod'} 25.0

SumObserver:

// Create SumObserver metric
meter.createSumObserver('SumObserver', {
    description: 'Example of a sync sum observer with callback',
}, (observerResult) => {
    const value = getMetrics(); // Calculte your metric value
    const labels = { environment: 'prod' }; // Define some labels
    observerResult.observe(value, labels);
});
// In logzio you will see the following metrics:
// SumObserver_total{environment: 'prod'}

UpDownSumObserver:

// This function will calculate your metric value
function getAsyncValue() {
    return new Promise((resolve) => {
        setTimeout(()=> {
            resolve(Math.random());
        }, 100);
    });
}
// Create UpDownSumObserver metric
meter.createUpDownSumObserver('UpDownSumObserver', {
    description: 'Example of an async observer with callback',
}, async (observerResult) => {
    const value = await getAsyncValue(); // Calculte your metric value
    const labels = { environment: 'prod' }; // Define some labels
    observerResult.observe(value, labels);
});
// In logzio you will see the following metrics:
// UpDownSumObserver{environment: 'prod'}

ValueObserver:

// This function will calculate your metric value
function getSomeAsyncMetrics() {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            resolve({
                value1: Math.random(),
                value2: Math.random(),
            });
        }, 100)
    });
}

// Create ValueObserver metrics
const valueObserver = meter.createValueObserver('value_observer', {
    description: 'Example of a value observer metric',
});
const anotherValueObserver = meter.createValueObserver('another_value_observer', {
    description: 'Example of a value observer metric',
});

meter.createBatchObserver((observerBatchResult) => {
    getSomeAsyncMetrics().then(metrics => {
        const labels = { environment: 'prod' }; // Define some labels
        observerBatchResult.observe(labels, [
            valueObserver.observation(metrics.value1),
            anotherValueObserver.observation(metrics.value2),
        ]);
    });
});

// In logzio you will see the following metrics:
// value_observer{environment: 'prod'}
// another_value_observer{environment: 'prod'}