Multiple instances of simple chat with Node.js, Websocket - Socket.IO and Redis -

i trying create simple chat app node.js , websocket using socket.io. inspired myself german tutorial , single backend instance works well.

i have 2 instances of server in backend, should sync chat messages between each other , store chat history in redis. client should display last 10 messages current channel, when new chat-room joined.

i tried apply solution stackoverflow page issues. first

websocket connection 'ws://localhost:8080/socket.io/?eio=3&transport=websocket&sid=leqgvy0cvk9yaszbaaaa' failed: connection closed before receiving handshake response

error in console. , second, both clients receiving 'payload' messages in 1-sec interval. not understand how redis-sync mechanism works , not yet know how display chat history.

here code far:

var conf = require('./config.json'); var cluster = require('cluster'); var os = require('os');  if (cluster.ismaster) {   // create http server, not use listen   // way, have socket.io server doesn't accept     connections   var server = require('http').createserver();   var io = require('socket.io').listen(server);   var redis = require('socket.io-redis');      io.adapter(redis({ host: conf.redisuri, port: conf.redisport }));    setinterval(function() {     // workers receive in redis, , emit     io.emit('chat', {time: new date(), text:'payload'});   }, conf.syncintervall);  // set number of workers   (var = 0; < conf.numberofworkers; i++) {     cluster.fork();   }    cluster.on('exit', function(worker, code, signal) {     console.log('worker ' + worker.process.pid + ' died');   }); }  if (cluster.isworker) {   var express = require('express');   var app = express();    var http = require('http');   var server = http.createserver(app);   var io = require('socket.io').listen(server);   var redis = require('socket.io-redis');      // webserver     //app.listen(conf.defaultport);     server.listen(conf.defaultport);      // deliver static files     app.use(express.static(__dirname + '/public'));     // route / path     app.get('/', function (req, res) {         // send index.html in reponse         res.sendfile(__dirname + '/public/index.html');     });      // websocket      io.adapter(redis({ host: conf.redisuri, port: conf.redisport }));     // callback when client connects     io.sockets.on('connection', function (socket) {     // store room name in socket session client     socket.room = 'defaultchannel';     // send client room 1     socket.join('defaultchannel');     // echo client they've connected     socket.emit('chat', { time: new date(), text: 'you have connected room defaultchannel on server!' });     socket.emit('chat', { time: new date(), text: 'connected chat worker-node: ' + cluster.worker.id});     // if message received     socket.on('chat', function (data) {         // send other clients         console.log('the current channel', socket.room);         socket.broadcast.in(socket.room).emit('chat', { time: new date(), name: data.name || 'anonymous', text: data.text });     });     // if client joins channel     socket.on('join', function (room) {     // store room name in socket session client     socket.room = room;     // send client room 1     socket.join(room);     console.log('client joined room ' + room);     }); });  // log port number in console console.log('server running under http://127.0.0.1:' + conf.defaultport + '/');  }