Various metrics generators and http framework middlewares that can be used with a self reporting metrics registry to easily instrument metrics for a node app.
npm install measured-node-metricsVarious metrics generators and http framework middlewares that can be used with a self reporting metrics registry to easily instrument metrics for a node app.
``
npm install measured-node-metrics
`javascript
const express = require('express');
const { createProcessMetrics, createOSMetrics, createExpressMiddleware } = require('measured-node-metrics');
const registry = new SelfReportingMetricsRegistry(new SomeReporterImple());
// Create and register default OS metrics
createOSMetrics(registry);
// Create and register default process metrics
createProcessMetrics(registry);
// Use the express middleware
const app = express();
app.use(createExpressMiddleware(registry));
// Implement the rest of app
`
You can also create your own middleware if your not using express, (please contribute it)
`javascript
const { onRequestStart, onRequestEnd } = require('measured-node-metrics');
/**
* Creates an Express middleware that reports a timer on request data.
* With this middleware you will get requests counts and latency percentiles all filterable by status codes, http method, and uri paths.
*
* @param {SelfReportingMetricsRegistry} metricsRegistry
* @param {number} [reportingIntervalInSeconds]
* @return {Function}
*/
createExpressMiddleware: (metricsRegistry, reportingIntervalInSeconds) => {
return (req, res, next) => {
const stopwatch = onRequestStart();
req.on('end', () => {
const { method } = req;
const { statusCode } = res;
// path variables should be stripped in order to avoid runaway time series creation,
// /v1/cars/:id should be one dimension rather than n, one for each id.
const uri = req.route ? req.route.path : '_unknown';
onRequestEnd(metricsRegistry, stopwatch, method, statusCode, uri, reportingIntervalInSeconds);
});
next();
};
}
``