Windows visitors getting Site Can't Reach error: ERR_CONNECTION_CLOSED

My users that are using Windows are not able to visit my app. Everything else works fine. I’ve successfully tested on MacOs, IOs but it fails on Microsoft Windows.

Any ideas?

No solution I’m afraid, but we’ve had reports from some of our customers who are seeing disconnection errors. It doesn’t affect all users, and doesn’t seem to be specific to a type of OS (e.g. we can connect from a Windows machine). But there’s nothing showing in any of our dashboards, so as far as we can tell the service running on Fly.io is all good.
My only remaining hypothesis at the moment is that it’s a networking issue either at Fly, or somewhere upstream. But I’m also open to ideas and suggestions!

Check the TLS Handshake times and errors in the fly grafana dashboard (Sign in to Your Account · Fly).

If you see high latencies or lots of errors then that would be the issue.

We had the same problem last week and it was caused by a DoS at one of fly’s upstream provider. The DoS mitigation was functioning but some of the legitimate traffic was being affected.

Our mitigation was to migrate our app to a different IP address outside of the IP block affected by the DoS.

This is what the graphs looked like for us when we were affected:

2 Likes

This topic was automatically closed 7 days after the last reply. New replies are no longer allowed.