I have a slight problem with use of Node.js and socket.io on Heroku. It works fine locally but as soon as I push it to Heroku and go on the website it gives me the application error page. Looking at the logs there is no explicit error but I have a feeling what it might be. When I run it locally, I use sudo node server to start the app. Just node server gives the same effect as that on heroku.
So basically, my question is: How do I get Heroku to run in sudo mode, or how can I remove the need to use sudo altogether?
Apologies as this is my first time using socket.io, so I am a bit unfamiliar with the workings of the library.
P.S. I am using Express 3.
I would check into the port you are using. On a normal ubuntu machine for example you may have to use sudo for low numbered ports (such as port 80). Besides that Heroku has a lot of load balancing going on, so the port you will use to connect to the service may not be the same as the port you tell the instance to listen on.
I would try using port 5000 as per this example from Heroku
Nodejs with sockets
Related
I have two applications - browser based client and NodeJS based server that are both communicating using WebSockets (I'm using ColyseusJS library). Problem is, that everything works fine while I'm testing them on localhost but when I deploy the application to my Ubuntu VPS server it stops working.
The message I receive in the browser while trying to connect is:
WebSocket connection to 'ws://X.X.X.X:8001/?colyseusid=' failed: Error during WebSocket handshake: net::ERR_CONNECTION_RESET
So it reaches the server (because when server is disabled the message is "Error in connection establishment: net::ERR_CONNECTION_REFUSED") but it looks like it fails on Upgrade connection operation.
What is strange is that I managed to make it work yesterday (don't know how exactly), but had so much mess on my VPS that I decided to revert machine to it's starting state. After that it stopped working (code is unchanged). Maybe there are some additional dependencies that I need to install in order to make it work on my Ubuntu Server?
I would really appreciate your help.
Have you tried to port forward the port to the ip address of the said VPS in your router config? And also check out the firewalls.
I'm a student going into back-end development for the first time and are trying to learn Node.JS. I downloaded a pdf book about Node.JS from sitepoint called: "Jumpstart Node.JS". In following the instructions to set up the server on the command line, install the dependencies, and navigate to localhost:3000, i got nothing except the following message: "Connection refused: localhost:3000", Can somebody please tell me what might have went wrong and how to fix it?
Edit1:
The instructions i followed is about setting up a node.js server using the Node command line, thus no code, simply cmd commands, however, here is a quick summary of the process i followed:
Created an account on MongoLabs and then a database using the free pricing plan.
Installed express using the command: npm install -g express#.2.5.8.
Created an applications with default options using this command: express authentication.
modified the package.json file in system32
installed the dependencies by typing cd authentication, hitting enter, and then typing the command: npm install
Typed node app and hit enter.
According to the instructions i should have seen a message: "Welcome to express" but instead got the error message.
In following the instructions to set up the server on the command line, install the dependencies, and navigate to localhost:3000
It seems that you didn't start the server.
Somewhere between installing the dependencies and navigating to the URL you need to actually start the server if you want it to serve the request.
Check that there is no copy of the server running in the background, or that another app is using the port currently.
(Your firewall show allow you to see which app has been allocated to that port)
Because nodejs requires it to be the only app on that port running on your computer.
Also try a different port maybe?
I use app.listen(PORTNO) for running my express app.
It runs on 127.0.0.1:PORTNO but also on 127.0.0.1:3000
3000 is the default port no on which express runs out of box.
Why this unexpected behaviour?
I have tried setting the env variable to production and also using http.createServer(app).listen(PORTNO);
I am generating my express app files using express-generator.
I am on a windows machine if its relevant
UPDATE:
I start the server using npm start which runs bin\www, and it specifies the port to run the server.
But this does not explains the binding to two port :the one specified in app.js and the other in bin\www for the same app and the app being accessible from both of them.
Can you explain the why?
You should start your server using node server.js(filename). Try this if it helps since when you start it with npm it will get default configurations. And Moreover npm command is used to install the node modules(mostly) rather than running the server.
I am using Cloud 9 IDE to develop a simple CRUD application using Sails.js (node.js MVC framework). Up until today I had no trouble starting the Sails.js server.
Today, I've been trying to start the sails js server, but I keep getting this error:
warn: error raised: Error: listen EACCES
error: Server doesn't seem to be starting.
error: Perhaps something else is already running on port 8080?
I have checked my /config/local.js file and everything is just fine, as it should be. The port is set to process.env.PORT || 1337 so it shouldn't have any problems firing the server up.
I'm looking forward to your insight.
Thank you!
Open terminal and run this command:
$ lsof -i :8080
Output will show PID of process occupying port 8080: "httpd 1234 ....'
Then kill the process with this command
$ kill -9 1234
Sails will now run
Hmm-- looks like port 8080 isn't available. What happens if you try to switch the port? You may have another server running on that port. Or in some cases, hosts require the hostname to be set. I'd try switching the port first though.
The only real answer to this is: wait. C9 seems to kill servers in a weird way that causes Sails to jack up and blocks you from establishing another server. lsof -i doesn't show anything serving... but it still won't start. Seems to be an issue with Cloud 9 and Sails.js. If I serve a generic Node.js "Hello World" app on the same port, the issue doesn't occur. However, time, it seems, cures all. After awhile, Sails seems to snap out of it and starts serving again when lifted.
Incredibly weird.
I have this web app written with express and socket.io using node.js, the app works brillantly on localhost, but when i push to my ec2 server, it connects for like 20 seconds then disconnects, and then connects again etc...
giving me the error on the node console as
warn - websocket connection invalid
info - transport end
SERVER
app = express()
server = http.createServer(app)
io = require('socket.io').listen(server)
CLIENT
socket = io.connect()
I know the problem is not with my code, because I fully tested the web app on localhost, so the only problem is where this code is running, which is my ec2 instance?
There could be many possible reasons you can get this error:
You are using browser that partially or does not support websockets. You can check if your browser supports websockets here.
Using proxy that does not support websocket. If there is some server(load balancer) between your client and your node server that does not support websocket.
You are using socket.io version 0.9.1/0.9.1-1. This behaviour is a reported bug for this version. So upgrade to latest socket.io version which is 0.9.14.
Browser connectivity is firewalled/blocked.
Code related problem.
Make sure you're using latest versions of node, express and socket.io on your ec2. Also, provide some data about currently used versions both on your local machine and on ec2 instance.
Running on your local machine you don't have to deal with network latency, NAT issues, or firewalls. Running on EC2 you have all of those.
Web Sockets are relatively new and unstable. So to begin with be sure you're running the latest versions (and let us know what they are). Perhaps the version of socket.io installed on your local machine is different than the version installed in your EC2 server.
If there is no activity during those 20 seconds before losing the connection, one possibility is that keep-alive is set too low.
See https://groups.google.com/forum/?fromgroups=#!topic/socket_io/RUv70BguZ-U for a similar problem. The solution there was to use heartbeat to keep the connection open.
A bit more on socket.io heartbeats if you're not already using them:
Advantage/disadvantage of using socketio heartbeats