What does this graph on https://fly.io/apps/my-app/metrics represent?
The query is
sum(rate(fly_app_http_responses_count{app="my-app",cache=~"^.+$"}[15s])) by (cache) /
ignoring (cache) group_left sum(rate(fly_app_http_responses_count{app="my-app",cache=~"^.+$"}[15s]))
Edit: Cache Hits in Metrics and First look: static asset caching have more information on this