socket.io: Clients don't receive messages

I have server and clients in node.js.

Every time client connects to server:

var response = {};
if (currentPlayers < maxPlayers) {
    currentPlayers++;
    response.username = currentPlayers;

    players[currentPlayers] = {
        score: 0
    };

    socket.join('players');
} else {
    if (currentPlayers === maxPlayers) {
        //Set a little delay
        setTimeout(function () {
            //I also tried this:
            //players_sockets.forEach(function (s) {
            //    s.emit('start');
            //});


            io.to('players').emit('start');
        }, 1500);
    }
}

Server checks is there enough players for game, if it is, server emits start message. The problem is that some clients doesn’t receive this message(to be current: mobile devices(e.g. meizu mx5, iphone 5, iphone 5s and some others). I watched debug: they are using long-polling.

Desktop clients, which are connected with WebSocket are okay.

How i need to fix this? Or maybe I’m doing something wrong?

About this issue

Original URL
State: closed
Created 8 years ago
Comments: 16 (1 by maintainers)

Most upvoted comments

I’m no expert here just learning but isn’t the point of websockets to replace long polling?

Socket.io doesn’t replace long polling. And by design it can fallback to XHR long polling if web sockets are unavailable or socket.io isn’t too warm and fuzzy about the web socket implementation. For whatever reason some browsers/clients make it switch to the fallback. I worked on an application where I only wanted web sockets. So I enforced it via the connection configuration using `“transports” : [“websocket”]`` and used Modenizr to ensure web sockets were available. This did the trick for me and the browsers quit performing a fallback to XHR long polling.

baconbrad on Feb 23, 2021