Let us say we have 5 EDS clusters registered with Envoy. When an Endpoint for a particular cluster (cluster_1) changed, if a management server sends EDS update with resource list as (cluster_1), Envoy updates it stats correctly but it also increments update_empty stat for rest of the clusters.
It is because it fires an empty config update at this line
https://github.com/envoyproxy/envoy/blob/master/source/common/config/grpc_mux_impl.cc#L218
Is this intentional behaviour? If it is intentional, I think it is pretty confusing to update other clusters stats indicating that empty update has come where as the intention of management server is not that.