We don’t have a limit on response times exactly. If a connection doesn’t send or receive any bytes during a 60s window, we’ll close the connection. If it continuously sends or receives some data, we will not close the connection and the response will continue.
I’ve been looking at the metrics for the specific app you mentioned and it appears that the app itself is responding slowly.
Do you have metrics or logs that would give you latency numbers? We expose metrics to our users, some of them like fly_app_http_response_time_seconds might help. You can setup a Grafana dashboard for this, outlined in our docs. There’s also a pre-built Grafana dashboard with useful metrics.
Specifically, I’m seeing the same graph for both our proxy response times and your app’s response time. This would mean our proxy isn’t responsible for the slowness.