As far as I can tell, there's currently no way to know how close Envoy is to triggering circuit breaking for for pending requests or retries, since no stat is emitted for number of reqs in pending/retry state.

It would be great to have stats that allow monitoring the circuit breaking resource usage without having to enable them, to allow a sensible value to be selected by observing these stats.

Stats already exists for active conns/requests, so it would be nice to have this for all the circuit breakers.