Can socket.io client connect to two different ports on the same server?
Can socket.io client connect to two different server?
Sure:
var io1 = require('socket.io').listen(8001);
io1.sockets.on('connection', function (socket) {
socket.emit('news', { hello: 'world' });
});
var io2 = require('socket.io').listen(8002);
io2.sockets.on('connection', function (socket) {
socket.emit('flash', { hello: 'world' });
});
Perhaps this is an interesting read: (from github)
// connect at the same host / port as your website
var socket = io.connect();
// different port or host
var socket = io.connect('http://url.com');
// secure
var socket = io.connect('https://localhost');
Can socket.io client connect to two different ports on the same
server?
I assume both machines share same domain. I believe it can use long-polling(websockets, flashsockets, etc also work), even passing along cookie. But I still need to test this on Internet Explorer because that browser never does what I want...
Can socket.io client connect to two different server?
The big question is if those both machines are on different domains. If on same domain it will work just fine even passing along cookie(s). If they are on different domains then on some browser we fall-back to json-p transport(worst transport imaginable), but it will work. Unfortunately then the cookie is not passed along, because of same origin policy. Right now I am toying to get around this cookie restriction(hard problem)...
Related
I made a basic chat app using node.js, express and socket.io. It's not too different from the tutorial chat app for socket.io, it simply emits events between connected clients. When I ran it on port 3001 on my server, it worked fine.
Then I made a proxy server app using node-http-proxy which listens on port 80 and redirects traffic based on the requested url to various independent node apps I have running on different ports. Pretty straightforward. But something is breaking. Whenever anyone disconnects, every single socket dis- and re-connects. This is bad for my chat app, which has connection-based events. The client consoles all show:
WebSocket connection to 'ws://[some socket info]' failed: Connection closed before receiving a handshake response
Here's what I think are the important parts of my code.
proxy-server.js
var http = require('http');
var httpProxy = require('http-proxy');
//create proxy template object with websockets enabled
var proxy = httpProxy.createProxyServer({ws: true});
//check the header on request and return the appropriate port to proxy to
function sites (req) {
//webapps get their own dedicated port
if (req == 'mychatwebsite.com') {return 'http://localhost:3001';}
else if (req == 'someothersite.com') {return 'http://localhost:3002';}
//static sites are handled by a vhost server on port 3000
else {return 'http://localhost:3000';}
}
//create node server on port 80 and proxy to ports accordingly
http.createServer(function (req, res) {
proxy.web(req, res, { target: sites(req.headers.host) });
}).listen(80);
chat-app.js
/*
...other modules
*/
var express = require("express");
var app = exports.app = express(); //I probably don't need "exports.app" anymore
var http = require("http").Server(app);
var io = require("socket.io")(http);
io.on("connection", function (socket) {
/*
...fun socket.on and io.emit stuff
*/
socket.on("disconnect", function () {
//say bye
});
});
http.listen(3001, function () {
console.log("listening on port 3001");
});
Now from what I've read on socket.io's site, I might need to use something to carry the socket traffic through my proxy server. I thought that node-http-proxy did that for me with the {ws: true} option as it states in their docs, but apparently it doesn't work like I thought it would. socket.io mentions three different things:
sticky session based on node's built in cluster module
socket.io-redis, which allows separate socket.io instances to talk to each other
socket.io-emitter, which allows socket.io to talk to non-socket.io processes
I have exactly no idea what any of this means or does. I am accidentally coding way above my skill level here, and I have no idea which of these tools will solve my problem (if any) or even what the cause of my problem really is.
Obligatory apology: I'm new to node.js, so please forgive me.
Also obligatory: I know other apps like nginx can solve a lot of my issues, but my goal is to learn and understand how to use this set of tools before I go picking up new ones. And, the less apps I use, the better.
I think your intuition about needing to "carry the socket traffic through" the proxy server is right on. To establish a websocket, the client makes an HTTP request with a special Upgrade header, signalling the server to switch protocols (RFC 6455). In node, http.Server instances emit an upgrade event when this happens and if the event is not handled, the connection is immediately closed.
You need to listen for the upgrade event on your http server and handle it:
var proxy = httpProxy.createProxyServer({ws: true})
var http = http.createServer(/* snip */).listen(80)
// handle upgrade events by proxying websockets
// something like this
http.on('upgrade', function (req, socket, head) {
proxy.ws(req, socket, head, {target:sites(req.headers.host)})
})
See the node docs on the upgrade event and the node-http-proxy docs for more.
I have a chat server setup as such:
var port = Number(process.env.PORT || 5000);
var app = require('http').createServer(handler)
, io = require('socket.io').listen(app, {'log level':1, 'match origin protocol':true})
, fs = require('fs')
io.set('authorization', function (handshakeData, callback) {
console.log(handshakeData);
callback(null, true);
});
and then I handle some events:
io.sockets.on('connection', function(socket) {
socket.emit('handshaken', {id:socket.id}); // for HTML clients
socket.on('subscribe', function(roomId) {
doSubscribe(socket, roomId);
});
socket.on('unsubscribe', function(roomId) {
doUnsubscribe(socket, roomId);
});
socket.on('chat', function(data) {
doChat(data);
});
});
The client is on a different domain.
When I use the chat server via https, then everything is working fine. All the events are received. However, when I use http, I can see that the client can receive the 'handshaken' event, but nothing else is sent or received.
I wonder if this has anything to do with the socket.io authorization not working properly with non ssl connection.
However, in local environment, I can still use non ssl http://localhost:5000 as the chat server url without any issue. Is it also possible that this is an issue with Heroku?
UPDATE 1: After some investigation, if I use http url for the chat server, the server can emit to the client. The client can connect to the server, but cannot emit anything to the server (the server does not receive any emit).
Update 2: Some further investigations revealed that the chat server, under http, does received an emit, but only 1 emit. Any emit after that is not received.
It turned out that Sophos antivirus for Mac is the culprit here. After I disabled all web protection, my chat app works fine.
The interesting point here is that Sophos only targets Chrome browser, as Firefox and Safari work without any problem.
I'm trying to get this exmaple working on my own computer:
https://github.com/tamaspiros/simple-chat
I have node.js installed and have installed socket.io as well. The readme is informing me to change the IP addresses on these two lines:
var socket = io.listen(1223, "1.2.3.4");
var socket = io.connect("1.2.3.4:1223");
However, I'm not really sure what to change the IP addresses into. I would like to get the simple chat box application working on my own computer.
You just need to configure it in one like, for ie:
var socket = io.connect('adress:port');
where addres is Your socket.io server IP or hostname, and yyyy is port on which it listens.
after that, You can get and emit events with:
socket.on('news', function (data) {
console.log(data);
socket.emit('my other event', { my: 'data' });
});
on server listen for
and thats it.
Before making chat You can try just using this example from official socket.io: link
PS dont forget to add socket.io client file source on client side! :). The whole code should look like in the example in the provided link.
I'm trying to figure out how to horizontally scale my nodejs TCP Server.
Example server:
var socketServer = net.createServer(function (socket) {
// Identify this client
socket.name = socket.remoteAddress + ":" + socket.remotePort
// Put this new client in the list
clients.push(socket);
sockets[socket.name] = socket;
// Handle incoming messages from clients.
socket.on('data', function (data) {
// Write to a specific user
var socketName = "xx.xx.xx.xx:56512";
sockets[socketName].write("Hello!");
}
}).listen(8080);
The following example stores each new connection in an array so that we can write a message to a specific user down the road.
I would like to scale this with haproxy as the loadbalancer. But how can i get all of my servers to share the same array of connected clients?
Stickysessions is not a solution that would work for me, since two people talking (two clients) could be on different servers, so all servers somehow have to share the same array of connected clients.
Any ideas how this can be done?
An idea i had:
Is it maybe possible to store each connection in MySQL?
Edit
Maybe the only way of actually doing this is by using Redis?
Any ideas if that would be a suitable option? The load is going to be extremely heavy
1.Use Redis to share your session with your servers.
2.Write a Login-Server,all users should login in Login-Server.
firstly.Login-server will generate a session,and share session on Redis-server and return transaction server ip and port,
Secondly,Client receive ip and port, disconnect Login-server, and connect to the transaction server,
Lastly,You can provide several TCP servers to handle transaction,Login-server will balance load through ip and port. of course, you can use haproxy to do that.but i don't know how to configure it.
I am attempting to upgrade to socket.io 0.7.9 and have run in to problems.
I have used the basic example from the socket.io homepage. My server is:
var http = require('http'),
url = require('url'),
https = require('https'),
fs = require('fs'),
crypto = require('crypto'),
io = require('../'),
sys = require(process.binding('natives').util ? 'util' : 'sys'),
server = http.createServer(function(req, res){
res.writeHead(200, {'Content-Type': 'text/plain'});
res.end();
});
server.listen(80,"[MYIP]");
var io = io.listen(server), buffer=[];
io.sockets.on('connection', function (socket) {
socket.emit('news', { hello: 'world' });
socket.on('my other event', function (data) {
console.log(data);
});
});
It connects OK on some computers but not on others. It is the same across all browsers.
Does anyone know why this would happen? Could there be some local networking issue that causes this?
UPDATE
It appears that the people who are unable to connect from their computers are running anti virus with real time web shields that seem to block the connection. When they turn it off, it connects OK on some browsers...
I have been using socket.io and node.js for the last two months and some issues like yours happened to me too.
Firewalls are often a problem with the port 80, especially when used with a DNS (like in a corporate network) because they will temper with the headers of the socket packages. One work around could be to try another port.
My application has an apache server on the port 80 and my websocket is on the port 843, everything is working fine on Firefox and Chrome.
You can use the xhr-polling fallback option to bypass this type of errors by adding this script:
io.set('transports', ['websocket','xhr-polling']);
xhr-polling offers less real-time performance, but is really dependable and works on most browsers and network configurations.
I hope this will help you!