在node.js中进行长时间轮询-如果没有可用数据，如何“暂停”挂起的请求？

Question

I'm trying to implement an http long polling server in Node.js, and have no idea how to close/shutdown pending requests if a timeout is reached.

3 possible solutions come to my mind:

1. Store the pendingRequest with a timestamp in a hash/object, then call setIntervall, so that every 1/2/x secs the pendingRequests are removed if the timestamp is too old.
2. set a timeout on the socket connection

Both solutions don't seem very reasonable, so what would be the Node.js way to achieve something like this?

Answer 1

Why don't those sound reasonable? In particular, setting a timeout on the socket seems to make sense to me, as:

1. There is a built-in method for doing so
2. An event is fired when the connection times out, allowing you to do any necessary cleanup (eg calling end / destroy on the socket)

I would probably go this route so that Node handles the timeout behind the scenes; however, if it makes sense for your app, I don't see any harm in keeping a timestamp and expiring connections manually.

You may be interested in these articles, each of which handles expiring connections differently:

• Long polling in Node.js
• How to write a Long Polling Event Push Server with node.js