Metrics for connection entry to regions


Is there a way to see in the UI metrics about the regions connections are entering the Fly network when reaching deployed applications? I think there could be a good use case here for displaying such metrics for evaluating if the deployed regions are making sense for the actual incoming connections.

While I understand the goal is to deploy to regions close to users, sometimes network topology doesn’t map super well to geographic locations, and so me picking a region close to the users might not actually be the best choice in terms of how the anycast addresses are routing.

I see that there is the FLY_REGION env var that tells my application which region it is in, and I can see the Fly-Region header as well which tells me which region the connection came from, so I think using the built-in Prometheus metrics I could build these metrics into the app I’m preparing to migrate pretty easily which is awesome.

I think this is the type of metric that the built-in Fly dashboard and built-in metrics could probably provide to all applications though. Do you folks have any plans to expand the built-in metrics dash, and where’s the best place to make feature requests there?


The best way to consume Fly metrics is from Grafana, using our pre-built dashboard.

The metric query you’re looking for is

sum by(region)(rate(fly_edge_http_responses_count{app="your-app-name"})[$__rate_interval])

We do have plans to upgrade the metrics dashboard, but there’s no way we could provide enough features to match Grafana.