Okay, so I have created an ubuntu vm in the azure cloud, I have successfully launched nodejs, redis, socket.io, Express and all the components for a game I am writing.
I have setup azure endpoints on internal and external port 8080, and use app.listen(8080) in my js code.
When I browser to http://< app-name >.cloudapp.net:8080/ I can view the result of my nodejs application fine, it displays the html, css etc.
However when it attempts to start a socket connection (using socket.io) I get only this (on my chrome dev console under websockets):
HeadersPreviewResponseWebSocket Frames
Request URL:ws://<app-name>.cloudapp.net:8080/socket.io/1/websocket/13510496541533398587
Request Method:GET
Status Code:101 Switching Protocols
Request Headersview source
Connection:Upgrade
Host:<app-name>.cloudapp.net:8080
Origin:http://<app-name>.cloudapp.net:8080
Sec-WebSocket-Extensions:x-webkit-deflate-frame
Sec-WebSocket-Key:y5vueHE66phl70gle7KCtw==
Sec-WebSocket-Version:13
Upgrade:websocket
(Key3):00:00:00:00:00:00:00:00
Response Headersview source
Connection:Upgrade
Sec-WebSocket-Accept:dn+2lA6sMIXHLEmDS/Q4j/IIwxI=
Upgrade:websocket
(Challenge Response):00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00
It will also crash the nodejs app on azure when i try send anything using socket.emit() on the client (browser); in my azure ssh, it just says 'DEBUG: Program node app.js exited with code null' which isn't particularly helpful.
So it obviously isn't connecting properly? I have also tried in my nodejs listening on port 80, but then I don't even get the standard webpage (html,css,etc).
From what I have read online, it is very possible to get sockets working providing your not using the web role (which I assume the vm is not).
Any idea how I can get this to work? (and preferably on port 80)?
Edit: starting to wonder if this has nothing todo with sockets, realized I get the same switching protocol message, on my home vm (where it is working). Spin off question: How can I view crash details for a nodejs program on a ubunu azure vm?
There is a time out of around 60s on the Windows Azure loadbalancer.
Does it work if you send a message back to the client just after the websocket connection is established?
If it is the case you will have to implement some keep a live message send every minutes.
Related
I am running an Ubuntu server (DigitalOcean droplet) with 2 services. React (Create React App) frontend in PORT 3000 and Node.js backend/API in PORT 8765 with PM2(pm2.keymetrics.io).
Screenshot of PM2 running 2 services
The ports are open (3000 and 8765). I checked.
lsof command showing the open ports
Problem: When the frontend app (in my browser) tries to access the backend it returns the '503 Service Unavailable' status code.
Screeshot of the browser developer tools showing 503
Question: What could be the reason? Can you suggest any steps to try?
Note: It worked fine during the past few weeks. (I used to pull the new changes from the Bitbucket) But today I got this issue.
What I have tried so far
Restart the server. Same error.
Change the Backend port from 9000 to 8765
Run the same code in a fresh AWS EC2 instance. There it works fine.
Force to listen on IPv4 (based on #adel comment)
Screenshot using IPv4
I called the backend (using the frontend) multiple times and observed the running processes with the Ubuntu 'top' utility. See the below screenshot.
I noted that the process id for the backend node.js application process is 12225. And this process is repeatedly called even though '503 Service Unavailable' is returned.
It turned out that the backend application code returns this status code programmatically (with a try-catch block, whenever the error occurs)
try{
...
}
catch (e) {
res.send(503, ...)
}
I struggled this with for a few days. Hope this will help someone.
(with this finding the new problem is why the particular error happens on a particular server only. It works fine on EC2 instance. I think it is a different question.)
I have a node.js web gui and server running on a localhost port and another node.js web server running on another localhost port. I haven't been successful locating an example of access the 2nd web server from the 1st. I want to post a "GET" to the 2nd server and have it respond with the piece of data using XMLHttpRequest. Does someone have an example of something similar? Or is this even feasible?
I have created a simple GraphQL Subscription using Nest.js/Apollo GraphQL over Node.js. My client application which is a react.js/apollo client works find with the server. The client subscibes to the server via GraphQL similar to:
subscription
{
studentAdded
{
id
}
}
My problem is that it works only locally. When I deploy my server back-end to a hosted docker over internet, client won't receive data anymore.
I have traced the client, it sends GET request on ws://api.example.com:8010/graphql and receives the successful HTTP/1.1 101 Switching Protocols response. However, nothing is received from server like when the server was on my local machine. Checking the remote server log showed me that the client successfully connects to server. There, I can see onConnect log messages.
Now I need any guidance to solve the problem.
I check several things myself. Firstly, I thought WebSocket address is prohibited in the network but then realized that it is on same port as normal HTTP. Secondly, supposed that WebSocket messages/frames are transmitted over UDP but I was not correct, it is over TCP and no need to worry about network settings.
Additionally I have read several github threads and StackOverflow questions. But did not find any clue. I am not directly using Node.js/WebSocket, instead, I am using Nest.js/GraphqQL subscription. It has made my search tougher.
Your help is highly appreciated.
I'm trying to develop a web application in nodejs. I'm using an npm package called "simple-peer" but i don't think this issue is related to that. I was able to use this package and get it working when integrating it with a laravel application using an apache server as the back end. I could access the host machine through it's IP:PORT on the network and connect a separate client to the host successfully with a peer-to-peer connection. However, I'm now trying to develop this specifically in node without an apache back end. I have my express server up and running on port 3000, I can access the index page from a remote client on the same network through IP:3000. But when I try to connect through webrtc, I get a "Connection failed" error. If I connect two different browser instances on the same localhost device, the connection succeeds.
For reference: i'm just using the copy/pasted code from this usage demo. I have the "simplepeer.min.js" included and referenced in the correct directory.
So my main questions are: is there a setting or some webRTC protocol that could be blocking the remote clients from connecting? What would I need to change to meet this requirement? Why would it work in a laravel/webpack app with apache and not with express?
If your remote clients can not get icecandidates, you need TURN server.
When WebRTC Peer behind NAT, firewall or using Cellular Network(like smartphone), P2P Connection will fail.
At that time, for fallback, TURN server will work as a relay server.
I recommend coTURN.
Here is an simple implementation of simple-peer with nodejs backend for multi-user video/audio chat. You can find the client code in /public/js/main.js. Github Project and the Demo.
And just like #JinhoJang said. You do need a turn server to pass the information. Here is a list of public stun/turn servers.
I have a Node/Express app on server dedicated to sockets and on the client it's Angular 1.5. Running the code locally on http using the same architecture e.g. separate socket server it all works perfectly fine.
When I run the code locally it creates one connection and does very little polling via xhr. On cloudflare with https it does a lot of polling, reconnects continually and not all the messages seem to be getting to the web client
messages hit cloudflare which then redirects them to a loadbalancer running haproxy which then routes the requests to an app running in a docker instance on another machine.
Your Issue is most likely occuring beacause of an issue with cloudflare only allowing traffic to a limited set of ports. Try one of the ports listed in the below link for your server and try connecting to it.
https://support.cloudflare.com/hc/en-us/articles/200169156-Which-ports-will-Cloudflare-work-with-
After a lot of investigation I found the issue to be down to the config in haproxy. I needed to alter the timeouts around the socket routing.
This was nothing to do with ports not being open on cloudflare.
The following link helped me
http://blog.haproxy.com/2012/11/07/websockets-load-balancing-with-haproxy/