It's helpful to a client-side LB to know the total endpoint serving QPS when making LB decisions.
This could also be used as a signal for Envoy's least loaded LB.
Signed-off-by: Harvey Tuch <htuch@google.com>
Mirrored from https://github.com/envoyproxy/envoy @ 0d5bfe2db00075d12b163b27f130bbca8539ffbc