Feature request problem/solution:

It seems from A66 Otel Stats that you folks are open to adding additional metrics in the future. We'd like to request connection metrics (i.e grpc.client.new and grpc.client.closed counters as well as an grpc.client.open gauge to track all currently open connections, and the same 3 metrics on the server side). One example of a use case for these metrics is load balancing; Flooding your backends with too many connections as a result of using round_robin load balancers is a common problem, and as grpc continues to add support for new balancers which may reduce the number of connections (i.e. subsetting balancers), having a generally available solution for tracking both connections would be incredibly valuable.