OpenTelemetry Metrics SDK
This module contains the Metrics SDK of opentelemetry-js.
Used standalone, this module provides methods for manual instrumentation of code, offering full control over recording metrics for client-side JavaScript (browser) and Node.js.
It does not provide automated instrumentation of known libraries or host environment metrics out-of-the-box.
Installation
npm install --save @opentelemetry/api
npm install --save @opentelemetry/sdk-metrics
Usage
The basic setup of the SDK can be seen as followings:
const opentelemetry = require('@opentelemetry/api');
const { MeterProvider } = require('@opentelemetry/sdk-metrics');
opentelemetry.setGlobalMeterProvider(new MeterProvider());
const counter = opentelemetry.getMeter('default').createCounter('foo');
counter.add(1, { attributeKey: 'attribute-value' });
In conditions, we may need to setup an async instrument to observe costly events:
const observableCounter = opentelemetry.getMeter('default')
.createObservableCounter('observable-counter');
observableCounter.addCallback(async (observableResult) => {
observableResult.observe(1, { attributeKey: 'attribute-value' });
});
opentelemetry.getMeter('default')
.addBatchObservableCallback(batchObservableCallback, [ observableCounter ]);
async function batchObservableCallback(batchObservableResult) {
batchObservableResult.observe(observableCounter, 1, { attributeKey: 'attribute-value' });
}
Views can be registered when instantiating a MeterProvider
:
const meterProvider = new MeterProvider({
views: [
new View({ aggregation: new ExplicitBucketHistogramAggregation([0, 50, 100]), instrumentName: 'my.histogram'}),
new View({ name: 'my.renamed.counter', instrumentName: 'my.counter'})
]
})
Example
See examples/prometheus for an end-to-end example, including exporting metrics.
Useful links
License
Apache 2.0 - See LICENSE for more information.