The Surprising gRPC Client Bottleneck in Low-Latency Networks — and How to Get Around It Evgeniy Ivanov 9 min read · 8 hours ago 8 hours ago -- Listen ShareZoom image will be displayed“Improving anything but the bottleneck is an illusion.” — Eliyahu M. GoldrattAt YDB, we use gRPC to expose our database API to clients. Fortunately, we identified the root cause as a bottleneck on the client side of gRPC. Within a gRPC client, there are multiple gRPC channels, each supporting many RPCs (streams). gRPC channels to different gRPC servers have their own TCP connections. We tried both per-worker gRPC channels and channel pooling (all using the same arguments and sharing the same TCP connection).