Nodemon: Error: listen EADDRINUSE: address already in use :::5000

I'm creating a project and using nodejs, express for the backend. Everything works fine but as I make any change in the file, nodemon is unable to restart the server due to following error:

Error: listen EADDRINUSE: address already in use :::5000

index.js:

const express = require("express");
const morgan = require("morgan");
const mongoose = require("mongoose");
const cookieParser = require("cookie-parser");
const session = require("express-session");
const FileStore = require("session-file-store")(session);
const dotenv = require("dotenv");
var passport = require("passport");

dotenv.config();

const PORT = process.env.PORT || 5000;

const app = express();

.....

app.listen(PORT, () => console.log(`Server listening on port ${PORT}!`));

package.json

{
  "name": "chat-app-backend",
  "version": "0.0.0",
  "private": true,
  "scripts": {
    "start": "node index.js",
    "dev": "nodemon --ignore 'sessions/' index.js"
  },
  "dependencies": {
    "bcryptjs": "^2.4.3",
    "cookie-parser": "^1.4.5",
    "cors": "^2.8.5",
    "debug": "~2.6.9",
    "dotenv": "^8.2.0",
    "express": "~4.16.0",
    "express-session": "^1.17.0",
    "http-errors": "~1.6.2",
    "jade": "~1.11.0",
    "jsonwebtoken": "^8.5.1",
    "mongoose": "^5.9.4",
    "morgan": "~1.9.0",
    "passport": "^0.4.1",
    "passport-jwt": "^4.0.0",
    "passport-local": "^1.0.0",
    "passport-local-mongoose": "^6.0.1",
    "session-file-store": "^1.4.0",
    "uuid": "^7.0.2"
  },
  "devDependencies": {
    "nodemon": "^2.0.2"
  }
}

I've to explicitly kill the server from the terminal every time, which is not the optimal solution. I tried several things, but none are working. Even found some issue in nodemon GitHub issue page, but there also I couldn't find anything.

I'm also adding the output of lsof -i:5000, even if server I'm closing the server - *node 31625 rishav 20u IPv6 5300049 0t0 TCP :5000 (LISTEN)

Solution 1:

--delay helped me to fix both of issues

on auto-restart
stopping with ctrl-c
```
nodemon --delay 500ms app.js
```

And I also added:

process.once('SIGUSR2', function () {
  process.kill(process.pid, 'SIGUSR2');
});

process.on('SIGINT', function () {
  // this is only called on ctrl+c, not restart
  process.kill(process.pid, 'SIGINT');
});

Solution 2:

I had the same situation. If you are using Visual Studio Code, check your terminals. You might have other instances of the terminal that is already running your node server.

Solution 3:

I think that error happens to me when I shut down the server's terminal without turning off nodemon beforehand.

Then, usually the next day, nodemon starts acting weird.

How I solved it: What I noticed is that when running ps -fp $(grep -u my_username), I got several instances of nodemon up and running. So I did pkill -f nodemon, which killed all nodemon instances, and then relaunched nodemon and all was good again in the wonderful realm of my Linux server.

Solution 4:

You can try running your server on some other port like 3000.

If you still want to use the same port, then you can use the following command to get the list of running process on that particular port:

lsof -i tcp:3000

Use following command in the terminal to kill that running port:

sudo kill -9 $(lsof -i tcp:3000 -t)

Solution 5:

None of all the aforementioned solutions worked for me. I simply had to do this every time:

npx kill-port 5000