Flow Based Load Balancing

[gamer boii]

I have a set up where I have 1 gRPC-client serving multiple backend gRPC-servers. Now I want that the packets(flows) in each RPC call are mapped to 1 particular instance of gRPC-server. The mapping could be based on a 5 tuple hash(Source IP, port, Dest IP, port, Protocol)
Is there some way to achieve this?  As I am of the idea that gRPC uses a single long-lived session?

[yas...@google.com]

I am not sure I completely understand the question but I'll give it a shot. On any new RPC (can either be unary or streaming), after load-balancing is done, gRPC ends up choosing a backend server for that RPC. If there isn't an existing transport connection to that backend, a connection is started and a stream is started on that connection. For the entire duration of the RPC, the stream remains on the same transport and hence the same backend.