apache的Socket.io-套接字客户端1 ID在连接客户端2时刷新

Question

I am using socket.io in my cakephp3 application for showing status of their processed requests to the connected clients.

Socket script (Server.js) :

var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);
var jsdom = require("jsdom");
const { JSDOM } = jsdom;

var dom = new JSDOM("");
var $ = require("jquery")(dom.window);

io.on('connection', function(socket){
  console.log('A user connected');

  socket.on('Event 1', function(data, fn){

    // Data received successfully!!!
    fn();
    // Processing
    sock.emit('Return 1', {data});
  });
  socket.on('disconnect', function(){
    console.log('A user disconnected');
  });
  socket.on('Event 2', function(data){
    // Processing
    var uid = data['uid']; //adding same user socket
    if(!sockets_uid[uid]){
        sockets_uid[uid] = [];
    }
    sockets_uid[uid].push(socket);
    $.each(sockets_uid, function(i, sock){
        sock.emit('Return 2', res);  
    });                 
});

http.listen(2105, function(){
    console.log('Started on 2105');
});

Client javascript(client.js) placed in default.ctp (CakePHP default rendering layout) :

var nodeToken = "<?= $this->request->session()->read('nodeToken');?>";
var socket = io('http://localhost/node', {secure: true, query: {token: nodeToken}});
socket.on('connect_error', function(){
    console.log('Unable to connect);
});

The workflow is working as expected when client is connecting to the node server via http://localhost:2105 .

But on porting the code to production, I used apache(v2.4.7) to mask the port using Proxy Pass and rewrite to forward any requests to http://localhost/node . Apache2 config :

Upon connecting to node via apache, initial connection is established successfully and client is receiving the responses from the node server as expected. As socket-client connection is being written in default.ctp, the connection to the node server refreshes on each page refresh or redirect to any other view using same default.ctp layout.

The problem I am facing is, as soon as some action is performed-say calling another any view ctp, the parent client didn't able to receive any update pushed by the node server to the client.

If apache is not used and node server is directly connected with port in client.js then everything works as expected, so I suspect there must be some problem in apache2 proxy pass configuration. I have already enabled mod_proxy and mod_ws_proxy modules.

Any help would be highly appreciated.

Answer 1

After much googling and browsing, I found that after the page is reloaded or in my case, default.ctp layout is used for another view render, the socket connection is ungracefully terminated .

So, I solved this problem by maintaining 3 arrays for holding:

• Users => Sockets-IDSs
• Sockets-IDs => Sockets, and
• All Active sockets

Now, upon page refresh/socket disconnection, I removed the old terminated sockets and emit the event to the new sockets only.

socket.on('disconnect', function(){
    var socket_id = socket.id;
    var uid = uids_sockets[socket_id];
    delete sockets[socket_id];
    var temp_array = sockets_uid[uid];
    var index = temp_array.indexOf(socket_id);
    temp_array.splice(index, 1);
    sockets_uid[uid] = temp_array;
  });

Also, on the client side, I am emitting the start event on socket connect event, so after new connection is established, the event gets re-registered with the new socket.

All the configuration is not required if connection to the node is established directly without using Apache Proxy-pass Middleware .