Q: SignalR not closing some connections My web app has online 200 users. But when I check SignalR connections after 1 day - it counts near 5000, most 2-10 hours long.
It starts okay, but grows 500 connections per hour. It seems like some connections just don't close.
And when I try to send message to all SignalR clients - my app hangs with CPU load 100%.
What can be the issue? SignalR version 2.2.0.


A: If you're using any kind of reverse proxy or tunnel between IIS and the public internet make sure everything is up to date.
For me it turned out to be due to using an out of date Cloudflare Argo tunnel.
SignalR Core connections not being closed and bringing down IIS
