crontab 无法执行 coffee程序的问题

express框架下coffee程序：

http = require 'http'
EventEmitter = require('events').EventEmitter
exports.importRequestNumber = (db, datetime)->
  COL = db.collection 'requestData'
  em = new EventEmitter()
  process.nextTick ->
    em.emit 'query data'
  em.once '500', (err)->
    console.log 'Error in import_data: ' + err
    console.log err.stack
    return em.emit 'error', err
  em.once 'done', ->
    return em.emit 'end'
  em.once 'query data', ->
    body = ''
    reqGet = http.get "http://test.komoxo.com:5000/cut?date="+datetime,(response)->
      response.on 'data', (chunk)->
        body += chunk
      response.on 'end', ()->
        data = JSON.parse data
        em.emit 'update data', data
    reqGet.on 'error', (e)->
      em.emit '500', e
    reqGet.end()
  em.once 'update data', (data)->
    COL.update {date: datetime}, {$set: {count: data.data.a, total: data.data.n, placecount: data.data.c}}, {upsert: true}, (err)->
      if err
        em.emit '500', err
      em.emit 'done'

if !module.parent
  db = require('./db').defaultDb()
  argv = process.argv[2..]
  if argv[0]
    datetime = argv[0]
  l=exports.importRequestNumber db, datetime
  l.once 'error', ->
    process.exit -1
  l.once 'end', ->
    process.exit 0

直接用coffee命令执行程序没问题，但在crontab下执行报错 crontab 环境变量已设置运行程序，http.get请求时报

Failed to load c++ bson extension, using pure JS version (这个警告应该没影响的。。。)
Error in import_data: Error: connect ECONNREFUSED
Error: connect ECONNREFUSED
  at errnoException (net.js:646:11)
  at Object.afterConnect [as oncomplete] (net.js:637:18)

不知道，哪位大神遇到过类似问题，跪求帮助啊。。。