Seeing intermittent "Connection reset by peer"

Hello, I just deployed a new app. I have other apps that don’t have this issue, but both apps are relatively simple node apps. I don’t know what would be different with my new one.

If I repeatedly do curl -I every so often I’m getting “curl: (56) Recv failure: Connection reset by peer”. Most of the requests work fine. The app itself is just a basic express server with a few features; if it was a problem with the express server though I’d be seeing errors in logs. I don’t see any errors in the logs.

What can I do to look into this?

Of course, after I typed this out, I just tried it up to 30 times and it all worked. Was fly just having minor networking issues?

1 Like

One thought: you could try adding a trace to the curl command to see exactly what is happening behind the scenes with a request if you see a future issue e.g

curl -I --trace-ascii /tmp/curl.txt

Adjust the path to the output file as desired.

That results in a long page of waffle but it could help diagnose any issue as it shows the SSL, Fly request ID etc. All handy for debugging. Beyond just the initial headers. To see at what point it fails.

1 Like

We weren’t having any network issues that we know of. If it comes back, try running curl -v (or like @greg said) and see if it gets past the certificate. If it gets a certificate and then disconnects, it’s almost always the app doing something janky.

You can also test, this will tell you the region you’re connecting to. If is working everything on our end is probably good. Not always, but probably.

Thanks! Note that I was already curl-ing http so it wasn’t going through SSL. Seems fine now, will comment again if I see the issue.

1 Like