clustering proxy server

package.json

{
  "name": "ProxyServer",
  "version": "0.0.1",
  "private": true,
  "scripts": {
    "start": "NODE_ENV=production forever start -c coffee proxyserver.coffee",
    "stop": "forever stop proxyserver.coffee"
  },
  "dependencies": {
    "http-proxy": "*",
    "underscore": "*"
  }
}

proxyserver.coffee

#!/usr/bin/env coffee

###
Copyright (c) 2012 geta6
http://www.geta6.net/

Global Requirement:
  forever

Scripts:
  init    : npm install
  start   : npm start
  stop    : npm stop
  restart : npm restart
###   

_ = require 'underscore'
cluster = require 'cluster'
cpunums = (require 'os').cpus().length
http = require 'http'
proxy = require 'http-proxy'

if cluster.isMaster
  workers = {}
  killall = (msg) ->
    return (msg) ->
      console.error "Killing with received #{msg}"
      _.each workers, (worker) ->
        worker.kill()
        console.info "Worker died #{worker.pid}"
      console.error "Shutting down master process."
      process.exit 1

  for i in [0...cpunums]
    worker = cluster.fork()
    workers[worker.pid] = worker

  process.on 'uncaughtException', killall 'uncaughtException'
  process.on 'exit', killall 'exit'

  cluster.on 'death', (worker, code, signal) ->
    cluster.fork()
    console.log "Worker #{worker.process.pid} died"

else
  server = proxy.createServer (req, res, proxy) ->
    switch req.headers.host
      when 'hoge.example.com'    then port = 3030
      when 'fuga.example.com'    then port = 3031
      when 'poyo.example.com'    then port = 3032
      else port = 0
    if port > 3000
      proxy.proxyRequest req, res,
        host: req.headers.host
        port: port
    else
      res.writeHead 404
      res.end()

  server.listen 3000