I'm running a real time web application which uses Symfony 2 PHP framework on the backend. I want to implement websockets for my real time interaction. Is it possible to install a node.js server on the same machine as my Symfony 2 server to handle websocket connections? If so, is it standard to open another port (say 81) to handle the websocket connection?
Yes, it is possible. Why not? It's just another application.
As for the second question. You can either open another port, which is easy to handle (WebSockets are not limited with cross-origin policy) but you may lose some data (cookies) or you can put a proxy which will send HTTP requests to web server and WS requests to Node.JS server. The latter can be recognized by having special header Upgrade: websocket. Either way WebSocket server has to listen on different port (unless you are developing application entirely in Node.JS).
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We are using IIS and ISAPI DLL's to deliver our web application. We can see the websocket upgrade request coming from the browser in our ISAPI application. We could accept the request and pass the connection to a thread to continue the conversation. The thread would now be the "websocket server" so in this sense we are able to handle incoming http (and https on 443) then switch from http to websocket, is that right?
I am assuming Microsoft's implementation of websockets only works with asp.net?
Some people have said to me "put the websocket server on a different port and have the javascript connect to that port." But, then the websocket server is not using HTTPS (SSL).
For example:
var socket = new WebSocket('ws://echo.websocket.org');
I have lots of books and examples but this simple issue is eluding me.
The thread would now be the "websocket server" so in this sense we are able to handle incoming http (and https on 443) then switch from http to websocket, is that right?
Yes, if the client side send the request which contains the Upgrade: websocket, the websocket serve will switch from http to websocket.
I am assuming Microsoft's implementation of websockets only works with asp.net?
If you means the websocket .net library, it will just work with .net application like asp.net, it is developed based on the .net framework.
For example: var socket = new WebSocket('ws://echo.websocket.org');
As far as I know, the websocket also contains the secure connection like https.
Like below image shows:
More details about the difference between http and websocket, you could refer to below article:
https://developerinsider.co/difference-between-http-and-http-2-0-websocket/
I'm making an app using node.js' express framework which serves both html content over http and uses websockets for a chat feature. I'm wondering how I can accomplish both at the same time. My idea is to use a different port for websocket connections (so http requests would come to port 3000 and websockets would connect on port 3001) but I don't know if that's a good solution. I'm especially worried about deployment to something like heroku and if I can specify different ports for my app.
I'm wondering how I can accomplish both at the same time.
The webSocket protocol is specially designed so it can run on the same port as your regular web server requests. So, you don't need a separate port in order to have both a web server and chat running using webSockets.
This works because a webSocket connection is always initiated with an http request that sets a few special headers. The receiving web server can then detect those special headers and know that this incoming http request is actually a request to initiate a webSocket connection. With a particular response, the client and server then agree to "upgrade" the connection and switch to the webSocket protocol. From that point on, that particular TCP connection uses the webSocket protocol.
Meanwhile any incoming http request that does not have the special webSocket headers on it is treated by your web server as just a regular http request. In this way, the same server and the same port can be used for both webSocket connections and regular http requests. No second port is needed.
Another advantage of this scheme is that the client can avoid the cross-origin issues that it would run into if it was trying to use a different port than the web page it was loaded from.
I'm especially worried about deployment to something like heroku and
if I can specify different ports for my app.
If you were to actually use two ports, then you would need to create two separate servers, one listening on each port since a given server can only listen on one port. In node.js, the two servers could both be in the same node.js app (making it easier to share data between them) or you could put them in completely separate node.js processes (your choice).
And, if you used multiple ports, you'd also have to support CORS so that the browser would be allowed to connect to the separate port (to avoid same-origin restrictions).
I basically want to know if its possible to use Socket.io using the server-side only with no client side? BUT I want to know if my server-side can instead connect with a different site that I cannot use Socket.io to connect to.
Use PhantomJS to load the third-party site and then inject your own javascript into the page to catch events and send those events back to your own server.
socket.io is a two-way connection. Client <--> Server. You must have a socket.io endpoint at both ends to even establish a connection in the first place. And, then once you establish the connection, you must have agreed upon messages that can be exchanged between the two ends for it to do anything useful.
It is not useful to have a server-side socket.io that doesn't actually connect to anything and nothing connects to it. It wouldn't be doing anything, just sitting there waiting for someone to connect to it.
It is possible to have two cooperating servers connect to one another with socket.io (one server just acts like a client in that case by initiating the connection to the other server). But, again both endpoints must participate in the connection for the connection to even be established and certainly for it to do anything useful.
If you just want to download the contents of a site for scraping purposes, then you would not use socket.io for that. You would just use the nodejs http module (or any of several other modules built on top of it). Your server would essentially pretend to be a browser. It would request a web page from any random web server using HTTP (not socket.io). That web server would return the web page via the normal HTTP request. Your receiving server can then do whatever it wants with that web page (scrape it, whatever).
I have been breaking my head on understanding what exactly is socket.io and its role in the whole persistent communication between client and server in general. Some fundamental questions that keep coming up in my mind are :
Are node.js and socket.io server different ways of doing the same thing ? Like lighthttpd and apache ?
Why should I use socket.io server if I have node.js ?
Can I use socket.io client with another server side programming language like PHP ?
Are there alternatives to using socket.io client ?
Is socket.io client just another javascript library for websocket communication ?
Thanks :)
The Socket.IO server accepts connections from Socket.IO clients. This is not any different than any other server (such as a web server like Apache) accepting a connection from a client (such as a web browser like Internet Explorer).
Node.js is a platform built on top of the V8 JavaScript engine, which comes with a convenient library usually used for web and network applications. Socket.IO is a web-socket-like communication wrapper and RPC which enables servers and clients to communicate over a variety of transports (every thing from long-polling JSON to real Web Sockets). Generally, the Socket.IO server code runs in your JavaScript application running on top of Node.js, and the Socket.IO client runs in your JavaScript on a web browser. (Note that you can run the Socket.IO client in your Node.js application to, which I have used in the past as a quick RPC between multiple Node.js applications.)
There are Socket.IO clients available for many languages, and yes I believe there is one for PHP but I haven't used it personally.
If you want to communicate with a Socket.IO server, you must use a Socket.IO client. It is a protocol all on its own.
Are node.js and socket.io server different ways of doing the same thing ?
SocketIO is actually a I/O engine that permits realtime communication between client and server, unlike classic HTTP requests.
Why should I use socket.io server if I have node.js ?
Since both are differents, we can't compare.
Can I use socket.io client with another server side programming language like PHP ?
No, because socketIO server run in NodeJS environment.
Client first make a HTTP request, then socketIO send a static JS script to client.
This script establish the two-way communication.
But you can use socketIO server with different socketIO client implementation.
Are there alternatives to using socket.io client ?
Any socketIO client implementation can do the job since they connected to server.
But beware of asynchronous way of communication, like in Java or PHP.
Is socket.io client just another javascript library for websocket communication ?
Yes it is, but socketIO aims on reliability and easy to use, and also do best effort : It choose the best transport available for client.
Hope it helps !
Are node.js and socket.io server different ways of doing the same thing ? Like lighthttpd and apache ?
Socket.io is a framework/library for node.js
Why should I use socket.io server if I have node.js ?
It's a framework designed for two-way communication, use it if you want
Can I use socket.io client with another server side programming language like PHP ?
Technically yes. But then you would have to reimplement socket.io server in that other language to match it.
Are there alternatives to using socket.io client ?
Lots of, google for websocket/real time communication in [here put your language]
Is socket.io client just another javascript library for websocket communication ?
Socket.io client is a JavaScript library compatibile with socket.io server (which is JavaScript library as well, only on the server side, i.e. Node.js)
I'm going to use Socket.IO to handle websockets or XHR-polling to implement a realtime app
which is on the top of node.js.
Many people are so into proxying their node.js server and
I don't understand the true meaning of proxy except security reasons.
Is there other reason to set proxy to handle node?
I'm currently using nginx 1.1 as a webserver and proxy server.
Unfortunately, I have found that nginx 1.1 can support HTTP 1.1 but not websockets.
Should I just use Socket.IO without proxying?
Or If I really need to do it so, how can I set up proxying websockets with nginx or other alternatives?
You may have noticed that you can only run one server on any given TCP port. If you want to use node.js and any other web server, then you'll want to have a proxy server to send client requests to the correct backend server.