In hbase, on server-side, we have a short-circuit facility that bypasses RPC by directly hooking the client and server protobuf Services up to each other.
Passing through the Protobuf Service stub requires that the invocation be cast as protobufs – the invocation itself and all params are converted to protobuf to pass through the eye of the protobuf Service stub. Can we do better and make direct invocations w/o having to do the protobuf marshalling/unmarshalling? (Can we do it in a way that is not brittle in need of careful repair whenever a change is made?). It would make for some nice savings.