Heroku Nodejs application crashed after started - node.js

Question

My nodejs app is crashing in Heroku. I have two server running in two different ports. One for express routes and another for socket.io. Apps builds fine and deployed in Heroku. It starts, DB connection is OK, then a server daemon also works fine for some period. Then it change state to crashed. No error log after the crash and no reason for crash. Here is log from Heroku,
2020-04-22T14:52:19.980682+00:00 app[web.1]: > iLearn#1.0.0 start /app
2020-04-22T14:52:19.980683+00:00 app[web.1]: > PORT=5000 node server.js
2020-04-22T14:52:19.980683+00:00 app[web.1]:
2020-04-22T14:52:20.741515+00:00 app[web.1]:
2020-04-22T14:52:20.782048+00:00 app[web.1]: API server started on: 5000
2020-04-22T14:52:21.087402+00:00 app[web.1]: Messaging Manager started..
2020-04-22T14:52:21.087501+00:00 app[web.1]: MessagingManager::startDaemon
2020-04-22T14:52:21.089358+00:00 app[web.1]: Messaging server running on port:5001
2020-04-22T14:52:21.130079+00:00 app[web.1]: DB Connected
2020-04-22T14:52:21.132905+00:00 app[web.1]: {"timestamp":"2020-04-22T14:52:21.131Z","message":"DB Connected","level":"info"}
2020-04-22T14:52:26.097164+00:00 app[web.1]: MessagingManager::daemon
2020-04-22T14:52:31.100561+00:00 app[web.1]: MessagingManager::daemon
2020-04-22T14:52:36.107406+00:00 app[web.1]: MessagingManager::daemon
2020-04-22T14:52:41.112479+00:00 app[web.1]: MessagingManager::daemon
2020-04-22T14:52:46.116481+00:00 app[web.1]: MessagingManager::daemon
2020-04-22T14:52:51.121785+00:00 app[web.1]: MessagingManager::daemon
2020-04-22T14:52:56.127394+00:00 app[web.1]: MessagingManager::daemon
2020-04-22T14:53:01.136499+00:00 app[web.1]: MessagingManager::daemon
2020-04-22T14:53:06.136680+00:00 app[web.1]: MessagingManager::daemon
2020-04-22T14:53:11.144029+00:00 app[web.1]: MessagingManager::daemon
2020-04-22T14:53:16.145616+00:00 app[web.1]: MessagingManager::daemon
2020-04-22T14:53:16.792389+00:00 heroku[web.1]: State changed from starting to crashed
Here is my server.js file,
const express = require('express')
const MessagingManager = require("./util/messagingManager")
app = express()
bodyParser = require('body-parser');
require('dotenv').config();
port = process.env.PORT || 5000;
app.listen(port);
console.log('API server started on: ' + port);
app.use(express.static('public'))
//app.use(formidable());
app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());
app.set('view engine', 'pug');
app.set('views', './views')
var routes = require('./routes'); //importing route
app.use('/', routes); //register the route
const messagingApp = express();
const messagingServer = require("http").createServer(messagingApp);
const io = require("socket.io").listen(messagingServer);
let messagingManager = new MessagingManager()
messagingManager.startDaemon()
port = process.env.MESSAGING_PORT || 5001;
io.on("connection", socket => {
console.log("a user connected");
let id = socket.handshake.query.id
console.log(socket.id)
messagingManager.addConnection(id, socket)
socket.on("message", msg => {
if (msg.type == "MESSAGE_READ_STATUS")
messagingManager.setMessageStatus(msg)
else
messagingManager.sendMessage(msg)
});
socket.on("disconnect", () => {
//io.emit("chat message", msg);
});
socket.on("endsession", msg => {
//io.emit("chat message", msg);
console.log("session ended." + id)
messagingManager.removeConnection(msg.id)
socket.disconnect()
});
// not used
socket.on("session", msg => {
//io.emit("chat message", msg);
console.log("session established")
messagingManager.addConnection(msg.id, socket)
});
});
messagingServer.listen(port, () => console.log("Messaging server running on port:" + port));

Answer 1

It's hard to actually to know why the application crashed as log just says, application crashed without any message. Port binding error was not thrown and app listen callback function is called. Actual issue seems to be port. I have set port in both .env and package.json file. It overrides heroku dynamic port. Thanks #Beppe C to pointing out this. I deleted port variable from both .env and package.json and redeploy the app. Now it is working fine. Another issue is heroku app does not allow two port in the same application. So, I have to create two app. One for express HTTP route and another for socket.io. Hope it helps someone.