I am working on integrating a Spring-MVC application on our Ubuntu server. Currently we are using Etherpad for note-taking tasks in it. Etherpad is a NodeJS application with which multiple users can collaborate and work. It requires a special port to run.

The unfortunate situation we are having is that we tried ports other than 443 and 80, but many corporate networks seem to block it. So, we registered a sub-domain, and in our Apache load-balancer, proxy-passed it. This way, apache or tomcat instance wont interfere with etherpad.

But when I tried to run etherpad, I get Address in USE error. Is there some other way that we can use port-80 or better port-443 both for Etherpad and Apache.

Etherpad error :

[2017-07-07 09:51:40.891] [ERROR] console - Error: listen EADDRINUSE

Apache2 config :

<VirtualHost sub_domain.my_domain.com:80>
    ProxyPass / http://localhost:8085/  // Tomcat application
    ProxyPassReverse / http://localhost:8085/  // Tomcat application

Thank you.

  • 1
    Why don't you just change the port etherpad is listening to? That's just config file edit away. Then add a proxypass for /etherpad and that's that?
    – Ziazis
    Commented Jul 7, 2017 at 9:38
  • @Ziazis : Exactly what I did... It worked. Thanks. Commented Jul 7, 2017 at 9:47

1 Answer 1


Sort-of with some changes :]

You can assign another IP to your network card. Then configure Apache to run on one IP and Etherpad on the other.

If the server has a second Nic already, you can plug it in, set it up and do the same as above.

You could buy a small machine and set it up just for that task. For example, a Raspberry Pi (very low power usage, can be run headless too).


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .