request-stats

Get stats on your Node.js HTTP server requests.

Emits two events:

• request when ever a request starts: Passes a Request object that can later be used to query for the progress of a long running request
• complete when ever a request completes: Passes a stats object containing the overall stats for the entire HTTP request

Installation

npm install request-stats --save

Example usage

Get stats for each completed HTTP request:

var requestStats = require('request-stats')
var server = http.createServer(...)
 
requestStats(server, function (stats) {
  // this function will be called every time a request to the server completes
  console.log(stats)
})

Get periodic stats for long running requests:

var server = http.createServer(...)
 
var stats = requestStats(server)
 
stats.on('request', function (req) {
  // evey second, print stats
  var interval = setInterval(function () {
    var progress = req.progress()
    console.log(progress)
    if (progress.completed) clearInterval(interval)
  }, 1000)
})

API

Constructor

requestStats(server[, callback])

Attach request-stats to a HTTP server.

Initialize request-stats with an instance a HTTP server. Returns a StatsEmitter object. Optionally provide a callback which will be called for each completed HTTP request with a stats object (see stats object details below).

If no callback is provided, you can later attach a listener on the "complete" event.

requestStats(req, res[, callback])

Attach request-stats to a single HTTP request.

Initialize request-stats with an instance a HTTP request and response. Returns a StatsEmitter object. Optionally provide a callback which will be called with a stats object when the HTTP request completes (see stats object details below).

If no callback is provided, you can later attach a listener on the "complete" event.

StatsEmitter object

.on('complete', callback)

Calls the callback function with a stats object when a HTTP request completes:

{
  ok: true,           // `true` if the connection was closed correctly and `false` otherwise
  time: 0,            // The milliseconds it took to serve the request
  req: {
    bytes: 0,         // Number of bytes sent by the client
    headers: { ... }, // The headers sent by the client
    method: 'POST',   // The HTTP method used by the client
    path: '...',      // The path part of the request URL
    ip: '...',        // The remote ip
    raw: [Object]     // The original `http.IncomingMessage` object
  },
  res: {
    bytes: 0,         // Number of bytes sent back to the client
    headers: { ... }, // The headers sent back to the client
    status: 200,      // The HTTP status code returned to the client
    raw: [Object]     // The original `http.ServerResponse` object
  }
}

.on('request', callback)

Calls the callback function with a special Request object when a HTTP request is made to the server.

Request object

The Request object should not be confused with the Node.js http.IncomingMessage object. The request-stats Request object provides only a single but powerfull function:

.progress()

Returns a progress object if called while a HTTP request is in progress. If called multiple times, the returned progress object will contain the delta of the previous call to .progress().

{
  completed: false, // `false` if the request is still in progress
  time: 0,          // The total time the reuqest have been in progress
  timeDelta: 0,     // The time since previous call to .progress()
  req: {
    bytes: 0,       // Total bytes received
    bytesDelta: 0,  // Bytes received since previous call to .progress()
    speed: 0,       // Bytes per second calculated since previous call to .progress()
    bytesLeft: 0,   // If the request contains a Content-Size header
    timeLeft: 0     // If the request contains a Content-Size header
  },
  res: {
    bytes: 0,       // Total bytes send back to the client
    bytesDelta: 0,  // Bytes sent back to the client since previous call to .progress()
    speed: 0        // Bytes per second calculated since previous call to .progress()
  }
}

Acknowledgement

Thanks to mafintosh for coming up with the initial concept and pointing me in the right direction.

License

MIT