WebSockets not working if nodeProcessCountPerApplication is set to anything else than 1

Question

We have a nodeJS express app using feathers und we use websockets hosted on Windows Server with iisnode.

If we set nodeProcessCountPerApplication to 1 everything works fine. If we set it to 2 or zero we can not connect to the websockets any more.

Our code in app.js is basically this:

const socketio = require('@feathersjs/socketio');
const app = express(feathers());
app.configure(socketio());

Answer 1

A friend told me the solution to this answer:

• Install newest Version of IISNode
• use the following flag in web.config: nodeProcessStickySessions="true"

The newest version can be downloaded here: https://github.com/Azure/iisnode/releases

(Be aware: The official docu of iisnode is pointing to an older version!!! - at least right now, at the time of this answer)