用 pm2 防止“EADDRINUSE”？

Question

I am about to switch my node application server from phusion passenger to pm2.

Most of the ports of my apps are set to 3001. With passenger that's never been a problem, but with pm2 ports collide (EADDRINUSE).

Do I have to set a different port for every app to prevent port collisions?

Answer 1

Yes, of course you need to have each application listen on a different and free port. It is your app that listen to port, not PM2.

You can leave the same port in source code, but in this case, start your app like this to change port when starting your app:

// Work for express
PORT=3012 pm2 start -n "My Application" app.js

That's because express add this in your startter script:

var port  = normalizePort( process.env.PORT || '3509' );

Notice that other package may use another name env var, like NODE_PORT for example.