node.js timeout / task scheduling

I'm working on node application that would monitor user's online status. It uses socket.io to update online status for users we "observe" (as in, the users we are aware of on the page we're at). What I would like to introduce now is idle status, which would basically mean that after X time of inactivity (as in no request) the status would change from online to idle.

I do monitor all the sockets thus I know when connection was made, so I thought of using this.

My idea is to use setTimeout on every connection for this particular uses (clearing out the previous one if exists) and in setTimeout I would simply change user's status to idle and emit that status change to observers.

What I'm concerned about is performance and scalability of setting and clearning the timeout on every connection. So the question is, are there any issues in terms of the two above with such approach? Is there a better thing of doing it, perhaps a library that is better at handling such things?

via user1970395