socket.io server very delayed in registering client disconnects

Question

I have a socket.io connection using xhr as its only transport. When I load up the app in the browser (tested in chrome and ff), the socket connects and everything works wel

Answer 1

After some more debugging, I noticed the following configuration in the socket.io Manager object:

blacklist : ['disconnect']

That causes this branch from namespace.js to not process the event:

case 'event':
  // check if the emitted event is not blacklisted
  if (-~manager.get('blacklist').indexOf(packet.name)) {
    this.log.debug('ignoring blacklisted event `' + packet.name + '`');
  } else {
    var params = [packet.name].concat(packet.args);

    if (dataAck) {
      params.push(ack);
    }

    socket.$emit.apply(socket, params);
}

The change is detailed in this pull request https://github.com/LearnBoost/socket.io/pull/569. I understand why this is in place for XHR, since anyone could send an HTTP request with random session IDs trying to disconnect other users from the server.

What I plan to do instead is to check each new connection for an existing session id in the server, and make sure to run my disconnect logic before continuing with the connection logic.