librato-node
librato-node is a Node.js client for Librato Metrics (http://metrics.librato.com/)
Getting Started
Install
yarn add librato-node
Setup
Once librato.start is called, a worker will send aggregated stats to Librato once every 60 seconds.
var librato = require('librato-node');
librato.configure({email: 'foo@example.com', token: 'ABC123'});
librato.start();
process.once('SIGINT', function() {
librato.stop(); // stop optionally takes a callback
});
// Don't forget to specify an error handler, otherwise errors will be thrown
librato.on('error', function(err) {
console.error(err);
});Increment
Use librato.increment to track counts in Librato. On each flush, the incremented total for that period will be sent.
var librato = require('librato-node');
librato.increment('foo'); // increment by 1
librato.increment('foo', 2); // increment by 2
librato.increment('foo', 2, {source: 'bar'}); // custom sourceMeasurements
You can send arbitrary measurements to Librato using librato.measure. These will be sent as gauges. For example:
var librato = require('librato-node');
librato.measure('member-count', 2001);
librato.measure('response-time', 500);
librato.measure('foo', 250, {source: 'bar'}); // custom sourceTiming
Use librato.timing to measure durations in Librato. You can pass it a synchronous function or an asynchronous function (it checks the function arity). For example:
var librato = require('librato-node');
// synchronous
librato.timing('foo', function() {
for (var i=0; i<50000; i++) console.log(i);
});
// async without a callback
librato.timing('foo', function(done) {
setTimeout(done, 1000);
});
// async with a callback
var workFn = function(done) {
setTimeout(function() {
done(null, 'foo');
});
};
var cb = function(err, res) {
console.log(res); // => 'foo'
};
librato.timing('foo', workFn, cb);
librato.timing('foo', workFn, {source: 'bar'}, cb); // all timing calls also accept a custom sourceExpress
librato-node includes Express middleware to log the request count and response times for your app. It also works in other Connect-based apps.
var express = require('express');
var librato = require('librato-node');
var app = express();
app.use(librato.middleware());The key names the middleware uses are configurable by passing an options hash.
librato.middleware({requestCountKey: 'myRequestCount', responseTimeKey: 'myResponseTime'});Advanced
By default the librato-node worker publishes data every 60 seconds. Configure
this value by passing a period argument to the configure hash.
var librato = require('librato-node');
librato.configure({email: 'foo@bar.com', token: 'ABC123', period: 5000})Request Options
You can pass additional options for the HTTP POST to Librato using the requestOptions parameter. See request/request for a complete list of options. For example, to configure a timeout:
var librato = require('librato-node');
librato.configure({email: 'foo@bar.com', token: 'ABC123', requestOptions: {timeout: 250}})By default librato-node will retry up to 3 times on connection failures and 5xx responses using an exponential backoff strategy with a 100ms base. These defaults can be overridden using the requestOptions paramter. See requestretry for a list of options. For example, to limit to a single attempt:
var librato = require('librato-node');
librato.configure({email: 'foo@bar.com', token: 'ABC123', requestOptions: {maxAttempts: 1}})Contributing
Please follow our Code of Conduct when contributing to this project.
yarn install
yarn test
Deploying a new version
This module is automatically deployed when a version tag bump is detected by travis. Remember to update the changelog!
yarn version
History
librato-node is largely based off of Librato's own librato-rack. Visit that repository if you're running Ruby or for more information on Librato Metrics in general.