example statsd callback in node

README.md

setup and usage

• download folder
• cd into root
• npm install
• node index.js

Sample Output

COMP10929:statsd_example eric.mustin$ node index.js
Successfully sent 20 bytes

index.js

var StatsD = require('./test_client.js'),
var client = new StatsD({
      host: 'localhost',
      port: 8125,
      tags: { env: 'dev' },
      protocol: "udp"
  });
 
client.flush("some example message", function(error, bytes) {
  //this only gets called once after all messages have been sent
  if(error){
    console.error('Oh noes! There was an error:', error);
  } else {
    console.log('Successfully sent', bytes, 'bytes');
  }
})

package.json

{
  "name": "statsd_example",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "hot-shots": "^6.8.5",
    "safe-buffer": "^5.2.0"
  }
}

test_client.js

const dgram = require('dgram')
const lookup = require('dns').lookup // cache to avoid instrumentation
const Buffer = require('safe-buffer').Buffer


const MAX_BUFFER_SIZE = 1024 // limit from the agent

class Client {
  constructor (options) {
    options = options || {}

    this._host = options.host || 'localhost'
    this._port = options.port || 8125
    this._prefix = options.prefix || ''
    this._tags = options.tags || []
    this._queue = []
    this._buffer = ''
    this._offset = 0
    this._udp4 = dgram.createSocket('udp4')
    this._udp6 = dgram.createSocket('udp6')
  }

  flush (input, callback) {
    lookup(this._host, (err, address, family) => {
      if (err === null) {
        this._send(address, family, Buffer.from(input.toString(), 'utf-8'), callback)
      }
    })
  }

  _send (address, family, buffer, callback) {
    const socket = family === 6 ? this._udp6 : this._udp4

    socket.send(buffer, 0, buffer.length, this._port, address, callback)
  }
}

module.exports = Client