express-watcher

express-watcher

It is a middleware of monitoring Express router, this middleware can be used either globally or on a per-route basis and sends information of response time, used memory and CPU.

Install

$ npm install --save express-watcher

Usage

var resourceMonitorMiddleware = require('express-watcher').resourceMonitorMiddleware

// example without callback function
app.use(resourceMonitorMiddleware)

Using with Callback

var resourceMonitorMiddlewareCB = require('express-watcher').resourceMonitorMiddlewareCB

// example with callback function
app.use(function(req, res, next){
  resourceMonitorMiddlewareCB(req, res, next, function(diffJson){
    console.log(' diffJson : ', diffJson)
  })
})


// { 
//      diffRss: 0.0078125,
//      diffHeapTotal: 0,
//      diffHeapUsed: 0.012725830078125,
//      diffExternal: 0,
//      diffCpu: 0.000427 
// }

Functionality

1- Monitoring each response

Return object as a callback:

{ diffRss: 0.0078125,
  diffHeapTotal: 0,
  diffHeapUsed: 0.012725830078125,
  diffExternal: 0,
  diffCpu: 0.000427 }

And auto print:

2- Monitoring all time high information

All time high information is printed when closing (CRT+c) the node process

And auto print:

Reference

• https://www.dynatrace.com/blog/understanding-garbage-collection-and-hunting-memory-leaks-in-node-js/
• https://nodejs.org/api/process.html#process_process

License

MIT