Node.js error on Plesk domain: Error: listen EADDRINUSE: address already in use 0.0.0.0:3000

Symptoms

• While trying to run a Node.js application for a domain by using the Node.js Toolkit extension for Plesk by going to Domains > example.com > Node.js > Run Node.js commands, an error that is similar to the following appears
  
   

CONFIG_TEXT: next start
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command. Error: listen EADDRINUSE: address already in use 0.0.0.0:3000
at Server.setupListenHandle [as _listen2] (node:net:1774:16)
at listenInCluster (node:net:1822:12)
at doListen (node:net:1971:7)
at process.processTicksAndRejections (node:internal/process/task_queues:83:21)

Cause

Port 3000, which your Node.js application is attempting to use is already occupied by a service that the Premium Antivirus for Servers extension for Plesk uses:

# netstat -tulpn | grep :3000
tcp 0 0 127.0.0.1:3000 0.0.0.0:* LISTEN 1331/drwebd.real

Resolution

You can resolve the issue by changing the port that the Premium Antivirus for Servers extension's drweb service uses by doing the following:

1. Log into your server via SSH

2. Back up the Premium Antivirus for Servers extension config files by executing the following commands:

# cp -a /etc/drweb/drweb32.ini{,.back}

# cp -a /etc/drweb/drweb_handler.conf{,.back}

2. Open the /etc/drweb/drweb32.ini and /etc/drweb/drweb_handler.conf configuration files with your favorite command-line text editor

Warning: Updates to Plesk and its extensions may revert the changes that you've made to these configuration files

3. Find the Address line in the /etc/drweb/drweb_handler.conf file and change it to the following:
Note: The contents below change the port on which this service runs to 2999.

Address = inet:2999@localhost

4. Find the Socket line in /etc/drweb/drweb32.ini and change it to the following:

Socket = 2999, localhost

5. Save the changes and close the file

6. Execute the following command in order to restart the Dr.Web daemon:

systemctl restart drwebd.service

After this was been done, port 3000 will not be occupied by a service tied to the Premium Antivirus for Servers extension and you may start your own service on that port.