node.js timers doc unreferenced Timers unref() setTimeout(callback, delay, [arg], [...]) setTimeout setImmediate See the Node.js documentation on timeoutId. clearInterval(intervalId) setImmediate() clearTimeout(timeoutId) See the Node.js documentation on timeoutId. setTimeout unreferenced node.js timers doc unreferenced ref() setInterval(callback, delay, [arg], [...]) ref() unref() http://nodejs.org/api/timers.html Timers