Heroku - Application Error - ruby-on-rails

Question

I've created simple application with Ruby on Rails and I’ve tried to commit it on Heroku. I’ve followed this Getting Started on Heroku guide,
I finished it and try to open my page but I still see an Error:
Application Error:
An error occurred in the application and your page could not be
served. Please try again in a few moments.
If you are the application owner, check your logs for details.
Anybody know how to deal with it?
I don’t know what was happen but I’ve done this step, unfortunately I have another problem, I run a few commands:
# git add .
# git commit -m "my commit"
On branch master nothing to commit (working directory clean)
# git push heroku
master Everything up-to-date
# heroku open Opening
http ://eerie-meadow-9207.heroku.com/
# heroku restart
Restarting processes... done
# heroku open Opening
http ://eerie-meadow-9207.heroku.com/
And I see a message:
We're sorry, but something went wrong.
We've been notified about this issue and we'll take a look at it shortly.
From heroku logs [timestamps removed for clarity]:
app[web.1]: Started GET "/" for 77.236.11.34 at 2011-10-31 11:50:38 -0700
app[web.1]: Processing by StoreController#index as HTML
app[web.1]: Completed 500 Internal Server Error in 3ms
heroku[router]: GET eerie-meadow-9207.heroku.com/ dyno=web.1 queue=0 wait=0ms service=13ms status=500 bytes=728
heroku[nginx]: 77.236.11.34 - - [31/Oct/2011:11:50:38 -0700] "GET / HTTP/1.1" 500 728 "-" "Mozilla/5.0 (X11; U; Linux i686; pl-PL; rv:1.9.2.23) Gecko/20110921 Ubuntu/10.04 (lucid) Firefox/3.6.23" eerie-meadow-9207.heroku.com
app[web.1]:
heroku[web.1]: State changed from up to bouncing
heroku[web.1]: State changed from bouncing to created
heroku[web.1]: State changed from created to starting
heroku[web.1]: Starting process with command `thin -p 40376 -e production -R /home/heroku_rack/heroku.ru start`
heroku[web.1]: Process exited
app[web.1]: >> Maximum connections set to 1024
app[web.1]: >> Listening on 0.0.0.0:40376, CTRL+C to stop
app[web.1]: >> Thin web server (v1.2.6 codename Crazy Delicious)
heroku[web.1]: State changed from starting to up
app[web.1]:
app[web.1]: Started GET "/" for 77.236.11.34 at 2011-10-31 11:50:59-0700
app[web.1]:
app[web.1]: Processing by StoreController#index as HTML
app[web.1]: Completed 500 Internal Server Error in 4ms
app[web.1]:
app[web.1]: ActiveRecord::StatementInvalid (PGError: ERROR: relation "products" does not exist
app[web.1]: : SELECT a.attname, format_type(a.atttypid, a.atttypmod), d.adsrc, a.attnotnull
app[web.1]: FROM pg_attribute a LEFT JOIN pg_attrdef d
app[web.1]: ON a.attrelid = d.adrelid AND a.attnum = d.adnum
app[web.1]: WHERE a.attrelid = '"products"'::regclass
app[web.1]: AND a.attnum > 0 AND NOT a.attisdropped
app[web.1]: ORDER BY a.attnum
app[web.1]: ):
app[web.1]: app/controllers/store_controller.rb:3:in `index'
app[web.1]:
app[web.1]:
app[web.1]: cache: [GET /] miss
heroku[router]: GET eerie-meadow-9207.heroku.com/ dyno=web.1 queue=0 wait=0ms service=81ms status=500 bytes=728
heroku[nginx]: 77.236.11.34 - - [31/Oct/2011:11:50:59 -0700] "GET / HTTP/1.1" 500 728 "-" "Mozilla/5.0 (X11; U; Linux i686; pl-PL; rv:1.9.2.23) Gecko/20110921 Ubuntu/10.04 (lucid) Firefox/3.6.23" eerie-meadow-9207.heroku.com
app[web.1]:
app[web.1]:
app[web.1]: Started GET "/" for 77.236.11.34 at 2011-10-31 11:54:00-0700
app[web.1]: Processing by StoreController#index as HTML
I cannot understand it because on my netbook it works on localhost, any ideas?

Answer 1

Try using the command
heroku run rake db:migrate

Answer 2

Try restarting your app with heroku restart. Assuming your app runs fine locally, this should do the trick. It solved the issue for me as I only refactored the schema and the db:reset did not seem to do the trick.

Answer 3

Most of the time heroku issues are due to lack of privileges to access file system. In order for your application to work on heroku you must make sure it wont try to write anything to disk (but in temporary folder).
The typical example is js/css compiling process, e.g. with compass, for which you will find a solution on their knowledge database: http://devcenter.heroku.com/articles/using-compass
You should look further in the heroku logs see if there is any "permission denied" issue at application startup or during the first requests.

Answer 4

http://www.youtube.com/watch?v=p_3dIPgXgkg
If you already have your application built, go to the point in the video when he begins pushing the sample app to heroku. Unfortunately heroku returns hard to solve errors when uploading 3.1 apps for the first time. Follow the troubleshooting steps in the video and you'll be fine.

Answer 5

I had this issue when I was starting to create a discord bot and make it online. And I figured out the reason for this was using the node latest current version(v17.1), I wasted about 2 days for this and tried downgrading node version to v16.7.And to my surprise it worked!.
So I recommend downgrading to v16.7 or the latest LTS version when you are checking this and do install the current latest version
https://nodejs.org/ca/blog/release/v16.7.0/
Here's the full code
const { Client, Intents } = require('discord.js');
const { token } = require('./config.json');
// Create a new client instance
const client = new Client({ intents: [Intents.FLAGS.GUILDS] });
// WShen the client is ready, run this code (only once)
client.once('ready', () => {
console.log('Ready!');
});
// Login to Discord with your client's token
client.login(token);
const http = require('http');
const PORT = process.env.PORT || 3000;
const requestListener = function (req, res) {
res.writeHead(200);
res.end('Bot is up and running');
}
const server = http.createServer(requestListener);
server.listen(PORT);
setInterval(function() {
http.get("http://<your app name>.herokuapp.com");
}, 300000); // every 5 minutes (300000)
Note:Last 3 lines of this code is completely additional and what they do is stop heroku from putting app to sleep every 30 minutes

Answer 6

I had the same problem. Have a look at your Procfile and check if you have added the proper command in it such as web: python run.py. I wasn't able to connect then I placed the command heroku logs --tail to see what was the problem and I saw that within my Procfile I had a type mistake such as >>>web: oython run.py<<< making the app not work. So, pay attention to it. command: $echo web: python run.py > Procfile

Answer 7

Just make sure that in the data base, you have allowed "any IP Address" to connect. This is called whitelisting the IP Address. Example: 0.0.0/0. This is because Heroku, each time it spins up, uses a different IP address. But you can change it later using Heroku docs and the docs of your Database service provider.
https://i.stack.imgur.com/Ud2VJ.png
You can use this image as an example which is a screenshot of MongoDB Atlas

Answer 8

Before you start please allow access to your DB network from anywhere.
Well I have also faced this "Application error" problem once
that time I used these command lines
git init
git add .
git commit -m "my first commit"
heroku create YourAppName
git push heroku main
But as you know I got the "Application error"
Then I used these commands
heroku config:set NPM_CONFIG_PRODUCTION=false
git add .
git commit -m "my first commit"
git push heroku main
After that "Application error" problem was solved.
Well, I'm not sure if it works for you or not but I guess you can try at least.