Node js socket io connection fails when two machines are running

[lubien]

I have a hunch! It might be related to being routed in between machines. This topic below talks about it and has an example repo:

How to set up session affinity with nginx for socket.io

May be a duplicate but none of the related posts seems to have an answer. I’m having “Session Unknown” issue with socket.io, and looking into setting up a custom load balancer with session affinity to resolve this. However I’ve got no idea where to start because of my lack of knowledge on how Fly.io’s public load balancer works. Can I customize the default fly.io load balancer to achieve this? adding a custom hashing logic (ip based) to the default load balancer perhaps? If not, is it rec…

If that is not enough, can you try debugging with this? Troubleshooting connection issues | Socket.IO