I am using easyrtc and socket.io for my metaverse application. The socket.io uses pollings and websocket connection for providing the multiuser experience in my metaverse.
The client sends polling requests to my server for connection.
At times the path at which the client sends request is taken as localhost:3000 which is my client itself. I want it to serve requests to my server that is present at localhost:3333.
Sometimes it sends requests to localhost:3000 and sometimes it sends the requests correctly to localhost:3333.
Can someone help?
Related
we have a front end of Angular, backend on Node.js, Apache as web server and socket.io install, when a user refreshes the browser (client) the apache gets a GET request with transport=websocket for the session ID which has been closed/disconnected, which is what it should get as the previous session was keep alive and apache will receive it when the connection closes.
The issue is that our node.js socket.io implementation is responding to the request with 200 status, now when the server responds with 101 as the session ID is already disconnected that packet out will essentially be lost in transit.
Should we be responding with 101 at all, or instead invalidate the request with 400?
I have one api for stock trade.
this is the url for websocket communication with api server.
https://kite.trade/docs/connect/v3/websocket/
I've read about websocket for laravel, but almost are the content about sending socket request from client to server.
If then, in my case, I have to turn on browser all day long to get live market quote.
I want to make it possible to get live market data without turn on browser.
Till my understanding is, in node.js, using socket.io client, it is possible to send websocket request from server to socket server.
But in laravel, I could not find way.
If anyone has experience, please help me.
Thanks.
wss://www.mysite.ca/socket.io/?EIO=3&transport=websocket
This is how chrome webdevoloper tools shows the request url of a socket io.
I am trying to understand more about EIO=3&transport=websocket .
I have to invoke the url from an API tool
These are query parameters that the socket.io client sends to the socket.io server as part of the initial connection request.
EIO=3, I believe, is the version number of the engine.io sub-system in socket.io. If the server is not compatible with this version number, it will likely fail the attempt to connect.
transport=websocket says that socket.io wants to use the websocket protocol as the eventual transport. socket.io has several different transports it supports including web polling and a flash-based protocol.
To connect to socket.io server, you will need a full-fledged socket.io client. You can't make a socket.io connection by just sending a URL from a tool to the server. There's a lot more involved than that in establishing a working socket.io connection.
I am learning about: Client/Server Architecture (more concretely the characteristics). I have a question:
"Asymmetrical protocols: there is a many-to-one relationship between
clients and a server. Clients always initiate a dialog by requesting a
service. Servers wait passively for requests from clients." (Source:
https://docs.oracle.com/cd/E13203_01/tuxedo/tux80/atmi/intbas3.htm)
QUESTION: I do not understand, I see that like SYMMETRICAL.
For example: A client request a service (web page) to a server (web server), but before this request the server was waiting passively until it received a request from client, just in that moment there is a connection between client and server, the server says "here you have the web page which you requested". For that moment I think it is SYMMETRICAL.
So, why is it asymmetrical?
There is a many to one relation between clients and server, so there is a single server and many clients but a single server per client.
The client actively sends requests, while the server serves the request and does not initiate requests on its own.
The client is active and the server is passive, so it is assymetrical.
I'm trying to get a better understanding of how the server-side architecture works for WebSockets with the goal of implementing it in an embedded application. It seems that there are 3 different server-side software components in play here: 1) the web server to serve static HTTP pages and handle upgrade request, 2) a WebSockets library such as libwebsockets to handle the "nuts and bolts" of WebSockets communications, and 3) my custom application to actually figure out what to do with incoming data. How do all these fit together? Is it common to have a separate web server and WebSocket handling piece, aka a WebSocket server/daemon?
How does my application communicate with the web server and/or WebSockets library to send/receive data? For example, with CGI, the web server uses environmental variables to send info to the custom application, and stdout to receive responses. What is the equivalent communication system here? Or do you typically link in a WebSocket library into the customer application? But then how would communication with the web server to the WebSocket library + custom application work? Or all 3 combined into a single component?
Here's why I am asking. I'm using the boa web server on a uClinux/no MMU platform on a Blackfin processor with limited memory. There is no native WebSocket support in boa, only CGI. I'm trying to figure out how I can add WebSockets support to that. I would prefer to use a compiled solution as opposed to something interpreted such as JavaScript, Python or PHP. My current application using long polling over CGI, which does not provide adequate performance for planned enhancements.
First off, it's important to understand how a webSocket connection is established because that plays into an important relationship between webSocket connections and your web server.
Every webSocket connection starts with an HTTP request. The browser sends an HTTP request to the host/port that the webSocket connection is requested on. That request might look something like this:
GET /chat HTTP/1.1
Host: example.com:8000
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
Sec-WebSocket-Version: 13
What distinguishes this request from any other HTTP request to that server is the Upgrade: websocket header in the request. This tells the HTTP server that this particular request is actually a request to initiate a webSocket connection. This header also allows the web server to tell the difference between a regular HTTP request and a request to open a webSocket connection. This allows something very important in the architecture and it was done this way entirely on purpose. This allows the exact same server and port to be used for both serving your web requests and for webSocket connections. All that is needed is a component on your web server that looks for this Upgrade header on all incoming HTTP connections and, if found, it takes over the connection and turns it into a webSocket connection.
Once the server recognizes this upgrade header, it responds with a legal HTTP response, but one that signals the client that the upgrade to the webSocket protocol has been accepted that looks like this:
HTTP/1.1 101 Switching Protocols
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=
At that point, both client and server keep that socket from the original HTTP request open and both switch to the webSocket protocol.
Now, to your specific questions:
How does my application communicate with the web server and/or
WebSockets library to send/receive data?
Your application may use the built-in webSocket support in modern browsers and can initiate a webSocket connection like this:
var socket = new WebSocket("ws://www.example.com");
This will instruct the browser to initiate a webSocket connection to www.example.com use the same port that the current web page was connected with. Because of the built-in webSocket support in the browser, the above HTTP request and upgrade protocol is handled for you automatically from the client.
On the server-side of things, you need to make sure you are using a web server that has incoming webSocket support and that the support is enabled and configured. Because a webSocket connection is a continuous connection once established, it does not really follow the CGI model at all. There must be at least one long-running process handling live webSocket connections. In server models (like CGI), you would need some sort of webServer add-on that supports this long-running process for your webSocket connections. In a server environment like node.js which is already a long running process, the addition of webSockets is no change at all architecturally - but rather just an additional library to support the webSocket protocol.
I'd suggest you may find this article interesting as it discussions this transition from CGI-style single request handling to the continuous socket connections of webSocket:
Web Evolution: from CGI to Websockets (and how it will help you better monitor your cloud infrastructure)
If you really want to stick with the stdin/stdout model, there are libraries that model that for your for webSockets. Here's one such library. Their tagline is "It's like CGI, twenty years later, for WebSockets".
I'm trying to figure out how I can add WebSockets support to that. I
would prefer to use a compiled solution as opposed to something
interpreted such as JavaScript, Python or PHP.
Sorry, but I'm not familiar with that particular server environment. It will likely take some in-depth searching to find out what your options are. Since a webSocket connection is a continuous connection, then you will need a process that is running continuously that can be the server-side part of the webSocket connection. This can either be something built into your webServer or it can be an additional process that the webServer starts up and forwards incoming connections to.
FYI, I have a custom application at home here built on a Raspberry Pi that uses webSockets for real-time communication with browser web pages and it works just fine. I happen to be using node.js for the server environment and the socket.io library that runs on top of webSockets to give me a higher level interface on top of webSockets. My server code checks several hardware sensors on a regular interval and then whenever there is new/changed data to report, it sends messages down any open webSockets so the connected browsers get real-time updates on the sensor readings.
You would likely need some long-running application that incoming webSocket connections were passed from the web server to your long running process or you'd need to make the webSocket connections on a different port than your web server (so they could be fielded by a completely different server process) in which case you'd have a whole separate server to handle your webSocket requests and sockets (this server would also have to support CORS to enable browsers to connect to it since it would be a different port than your web pages).