nodeJS mongoDB instrumentation – This allows you to profile all queries to your mongoDB collection, including collectionName, special find parameters and conditions.

instrumenting_mongodb.coffee

collection = require("mongodb/lib/mongodb/collection").Collection

oldFind = collection.prototype.find

collection.prototype.find = ->
  tagName = "#{@db.databaseName}/#{@collectionName}/find"
  findParameters = arguments[1]
  start = +new Date()

  cursor = oldFind.apply @, arguments

  selectorParameters = cursor.selector

  oldArray = cursor.toArray

  cursor.toArray = (cb) ->

    instrumentedCb = =>
      console.log tagName, +new Date() - start
      if findParameters
        console.log findParameters
      if selectorParameters
        console.log selectorParameters

      cb.apply cursor, arguments

    oldArray.apply cursor, [instrumentedCb]

  cursor