Sample Express app with domain wrapping

index.js

var app = require('express')()
  , server = require('http').createServer(app)

app.use(function (req, res, next) {
  console.log('Handling', req.path, process.pid)

  var d = require('domain').create()
  d.add(req)
  d.add(res)

  d.on('error', function (err) {
    console.log('error', err)
    next(err)
    d.dispose()

    cluster.worker.disconnect()
  })

  req.domain = d
  d.run(next)
})

var defer = require('when').defer()

app.use(function (req, res, next) {
  defer.promise.then(function () {
    req.domain.run(next)
    // next()
  })
})
app.get('/', function (req, res) {
  res.send('hello')
})

app.get('/slow', function (req, res) {
  setTimeout(function () {
    res.send('eventual response')
  }, 10000)
})

app.get('/throw', function (req, res) {
  setTimeout(function () {
    throw new Error('fdsa')
  }, 10)
})

server.listen(process.env.NODE_PORT, function () {
  defer.resolve()
  setTimeout(function () {
    process.send('ready')
  }, 5000)
})