Number of connections to socket.io?

Question

JavaScript

How do you count connections to socket.io?
Tried like this: Object.keys(io.sockets.connected).length
And like this: io.sockets.sockets.length
And also like this:

var count = 0;
io.on('connection', function(socket) {
  console.log(++count);
  socket.on('disconnect', function() {
    console.log(--count);
  });
});

Everywhere there is one problem: with a very frequent page refresh, the number of connections increases (disconnect does not have time to work, as I understand it) and all left connections are eliminated after about a minute, how can it be in this case?

Answer 1

Something one subscription to the topic, no answers, no one knows how to solve this problem?
There is an idea to look at the minimum data exchange through sockets and navigate according to this data, but maybe there are much more profitable solutions?

Answer 2

Maybe this solution will work:
https://coderwall.com/p/ekrcyw/socket-io-managing-...

Answer 3

Writing to the session or database, and when disconnecting, delete the required sid accordingly