Measured Reporting

The registry and reporting library that has the classes needed to create a dimension aware, self reporting metrics registry.


Install

``
npm install measured-reporting
`

What is in this package

$3

A dimensional aware self-reporting metrics registry, just supply this class with a reporter implementation at instantiation and this is all you need to instrument application level metrics in your app.

See the SelfReportingMetricsRegistryOptions for advanced configuration.

`javascript
const { SelfReportingMetricsRegistry, LoggingReporter } = require('measured-reporting');
const registry = new SelfReportingMetricsRegistry(new LoggingReporter({
defaultDimensions: {
hostname: os.hostname()
}
}));

// The metric will flow through LoggingReporter#_reportMetrics(metrics) every 10 seconds by default
const myCounter = registry.getOrCreateCounter('my-counter');

`

$3

Extend this class and override the _reportMetrics(metrics) method to create a vendor specific reporter implementation.

See the ReporterOptions for advanced configuration.

#### Current Implementations
- SignalFx Reporter in the measured-signalfx-reporter package.
- reports metrics to SignalFx.
- Logging Reporter in the measured-reporting package.
- A reporter impl that simply logs the metrics via the Logger

#### Creating an anonymous Implementation
You can technically create an anonymous instance of this, see the following example.
`javascript
const os = require('os');
const process = require('process');
const { SelfReportingMetricsRegistry, Reporter } = require('measured-reporting');

// Create a self reporting registry with an anonymous Reporter instance;
const registry = new SelfReportingMetricsRegistry(
new class extends Reporter {
constructor() {
super({
defaultDimensions: {
hostname: os.hostname(),
env: process.env['NODE_ENV'] ? process.env['NODE_ENV'] : 'unset'
}
})
}

_reportMetrics(metrics) {
metrics.forEach(metric => {
console.log(JSON.stringify({
metricName: metric.name,
dimensions: this._getDimensions(metric),
data: metric.metricImpl.toJSON()
}))
});
}
}()
);

// create a gauge that reports the process uptime every second
const processUptimeGauge = registry.getOrCreateGauge('node.process.uptime', () => process.uptime(), {}, 1);
`

Example output:
`bash
APP5HTD6ACCD8C:foo jfiel2$ NODE_ENV=development node index.js
{"metricName":"node.process.uptime","dimensions":{"hostname":"APP5HTD6ACCD8C","env":"development"},"data":0.092}
{"metricName":"node.process.uptime","dimensions":{"hostname":"APP5HTD6ACCD8C","env":"development"},"data":1.099}
{"metricName":"node.process.uptime","dimensions":{"hostname":"APP5HTD6ACCD8C","env":"development"},"data":2.104}
{"metricName":"node.process.uptime","dimensions":{"hostname":"APP5HTD6ACCD8C","env":"development"},"data":3.105}
{"metricName":"node.process.uptime","dimensions":{"hostname":"APP5HTD6ACCD8C","env":"development"},"data":4.106}
`


Consider creating a proper class and contributing it back to Measured if it is generic and sharable.

$3

A simple reporter that logs the metrics via the Logger.

See the ReporterOptions for advanced configuration.

`javascript
const { SelfReportingMetricsRegistry, LoggingReporter } = require('measured-reporting');
const registry = new SelfReportingMetricsRegistry(new LoggingReporter({
logger: myLogerImpl, // defaults to new console logger if not supplied
defaultDimensions: {
hostname: require('os').hostname()
}
}));
``

What are dimensions?

As described by Signal Fx:

*A dimension is a key/value pair that, along with the metric name, is part of the identity of a time series.
You can filter and aggregate time series by those dimensions across SignalFx.*

DataDog has a nice blog post about how they are used in their aggregator api.

Graphite also supports the concept via tags.