I would like to know if is possible create a socket connection using TCP protocol between servers.
For example: I have two servers, one is a API, and the other only services, so the API calls the service, how could i send messages if they aren't in the same machine?
I'm using ZeroMQ and i definitely need this separation.
Other import piece is about secure. Is TCP socket connections secure??
Thanks.
It is absolutely possible, and is the base for the internet. Your browser on your machine opens up sockets to remote servers perpetually.
There are so many ways to lock down TCP connections: spanning Network Level, OS level, or application level.
If you need to encrypt the data you are sending TLS/SSL is the defacto way, if your servers are on your own private subnet with no access to the outside, unencrypted communication is often used.
I've never used ZeroMQ, but if you are using it as a central store or message bus accross your services, you could bind it to an interface with the appropriate visibilty on your net, then connect to it from any of your servers.
Since it is 100% possible, I feel liek the issues become:
How should you expose their external interfaces?, on which level of abstraction should you expose your servers? ie.
Should they communicate through raw sockets?
Should they communicate through RPC?
Should they have a higher level interace like REST?
Should all communcation take place through a zeroMQ?
I would highly recommend whatever course you decide to take, you audit the security very careful and make sure that nothing is exposed to the outside world that shouldn't be.
You can use Redis for this purpose. If two servers (one is API and other you called as services) has to communicate other than API calls(client side). Then Redis pub/sub is good suggestion.
If they are not in same server
yes It can communicate within a machine or remotely.Depends upon how you configure it.
TCP Secure Socket
yes it can be configure to use SSL see Redis Encryption.
Here is great topic about this how to communicate via redis. see Real time communication over redis
Related
I have a c# tcp server, I want to connect to the server via a html client page.
The problem: There is no simple way to create TCP sockets in Javascript on a browser side. Although solutions like Websockets allow to create something that resemble sockets, you can use them to connect only to servers that support Websockets. Not to any random servers that know nothing about HTTP.
so is there a solution to connect to my srver.
No. There just isn't. The browser is a tightly locked down environment. The only socket connection that you can open from JavaScript is WebSocket. Since it's your server, adding WebSocket support shouldn't be too complicated, and there are WebSocket libraries available for C#.
Maybe someone else will have an idea for you, but...
The best solution I can think of is for your server to support websockets.
The situation you described - along with connectivity issues for traffic passing through proxies and routers - is one of the reasons Websockets were introduced in the first place.
Bare in mind that Websockets can send and receive binary data. It's just that javascript make it more comfortable to write text based messages.
Also, many NAT routers, Proxies and firewalls will block raw TCP/IP communication while allowing Http communication to pass through. This is why you have a better chance at connection establishment and retention when implementing the Websocket protocol.
I'm trying to build a website that allows you to transfer files to devices connected on your local network. This website is static, and will be hosted on GitHub pages.
Is it possible to use Javascript to communicate with (i.e. transfer files/text) other devices on the local network? The IP addresses of the devices are already known and I'm looking for a peer-to-peer connection here.
Note: As this website is static, there is no server side code that can be controlled.
Thanks
Yes, it's possible with caveats, depending on the specifics of your situation.
WebRTC
With WebRTC, you can establish a real peer-to-peer connection between two clients on a network. They can send data (binary or strings), and media streams (like webcams and microphones). This can even work from a static page.
The catch is that you need some sort of server to help coordinate the connection. Because of the way the WebRTC standard was originally set up, there is some back-and-forth that must occur to set up that peer-to-peer connection. Some method of communicating the signalling between the clients must exist, and this is usually done via web sockets and an intermediary server.
There are some novel alternatives.
In the future, ORTC may solve this issue, allowing a one-shot method for setting up the call, making the server-side requirements easier.
Embedded HTTP Server
You didn't elaborate on the specifics of what device you want to communicate with on your network, so maybe this is a possibility as well. There's nothing stopping your browser from communicating with devices on your LAN. Your static web page can use the Fetch API or AJAX to retrieve data from devices.
I'm new to Web Sockets in general, but get the main concept.
I am trying to build a simple multiplayer game and would like to have a server selection where I can run sockets on multiple IPs and it will connect the client through that, to mitigate connections in order to improve performance, this is hypothetical in the case of there being thousands of players at once, but would like some insight into how this would work and if there are any resources I can use to integrate this before hand, in order to prevent extra work at a later date. Is this at all possible, as I understand it Node.Js runs on a server and uses the Socket.io dependencies to create sockets within that, so I can't think of a possible solution to route it through another server unless I had multiple sites running it separately.
The first question I have is this:
Are you hosting on AWS or in a local datacenter?
The reason I ask is because SOCKET.io requires sticky sessions to work properly across multiple servers. Due to the fact that SOCKET.io will attempt to upgrade each connection, and because that upgrade request must reach the original server that authorized the session, you'll need to route websocket (TCP) connections back to that original server via sticky sessions. Unfortunately AWS makes this extremely tricky and will require you to learn how to:
A) Modify elastic load balancer policies to forward protocol information
B) Split apart TCP connections from standard web requests using something like HA PROXY or NGINX. This is necessary in order to handle web socket UPGRADE requests properly, as you will be setting TCP to sticky and web requests to round-robin.
C) Attach your socket.io configuration to a common storage source, like Redis (elasticache).
Once you've figured out what's needed for AWS (or if you've got full control over request routing at your local datacenter), you'll want to architect your SOCKET application to use multicast rooms rather than direct socket messaging.
Example:
To send a message to users in game #4444, emit a message to room 'games:4444', rather than direct to the user's socket.
If your socket instance is configured using REDIS, REDIS will automatically take care of maintaining lists of people who are connected to your 'games:4444' channel. Otherwise you'll need to maintain the list yourself using a database or other shared mechanism.
Other than that, there are plenty of resources online that can help you figure out each step along the way. I'd start with understanding something like HA PROXY and how it can help split apart your SOCKETS from your web requests.
I have a c# tcp server, I want to connect to the server via a html client page.
The problem: There is no simple way to create TCP sockets in Javascript on a browser side. Although solutions like Websockets allow to create something that resemble sockets, you can use them to connect only to servers that support Websockets. Not to any random servers that know nothing about HTTP.
so is there a solution to connect to my srver.
No. There just isn't. The browser is a tightly locked down environment. The only socket connection that you can open from JavaScript is WebSocket. Since it's your server, adding WebSocket support shouldn't be too complicated, and there are WebSocket libraries available for C#.
Maybe someone else will have an idea for you, but...
The best solution I can think of is for your server to support websockets.
The situation you described - along with connectivity issues for traffic passing through proxies and routers - is one of the reasons Websockets were introduced in the first place.
Bare in mind that Websockets can send and receive binary data. It's just that javascript make it more comfortable to write text based messages.
Also, many NAT routers, Proxies and firewalls will block raw TCP/IP communication while allowing Http communication to pass through. This is why you have a better chance at connection establishment and retention when implementing the Websocket protocol.
I would like to connect to to irc, icq, sip, etc services using WebSockets.
Assuming I have some sort implementation of those protocols in JavaScript ?
Is that possible? I don't seems to understand limitations of WebSockets comparing to regular sockets.
No, you can't, at least not directly.
WebSockets allow real-time messaging between a browser and a WebSocket server, but they have their own layer 7 protocol for encapsulating those messages.
They don't provide access to a pure TCP (or UDP) socket over which you can implement existing protocols.
Absolutely!
The caveat is that you need something to bridge between the WebSocket transport protocol of the browser and the raw TCP socket of the existing service. For example, something like websockify (disclaimer: I created websockify). Another caveat is that websockify only supports TCP targets (WebSocket is TCP only right now so supporting UDP targets would be a little odd anyways).
The websockify project actually includes two proof of concept HTML/Javascript pages to communicate with IRC and telnet. If you are interested in leveraging websockify to build HTML/Javascript clients for some common TCP protocols, I might even pull them into the websockify repo as examples (assuming they are well coded and under an open source license.
An alternative to websockify is to integrate websocket server-side support directly into the servers you wish to communicate with. It's not all that difficult to add support. WebSocket has a very simple framing and while the handshake is compatible with HTTP servers it's actually much more restricted and simple and doesn't require a full HTTP parser. For example, libvncserver 0.9.9 now supports both regular VNC connections and VNC connections over WebSocket. This allows noVNC (which I also created) to connect directly to a libvncserver based VNC server without requiring websockify.
Inspircd has an unofficial module you can install called m_websockets, to allow connection. A server that has the module installed and setup will allow you to connect to the server via webbsockets.
https://github.com/barosl/inspircd-m_websocket
Extending on #kanaka's websockify, this project seems to do it:
A HTML5 irc-client, made with websocket and websockify.
[Has] support for autojoin, privmsg channel, topic, join, userlist, part, nick.
https://github.com/confact/dunirc
No, not with websockets, but you can with http.
Samy Kamkar gave a black hat talk about this.