gRPC: A Deep Dive into the Communication Pattern

Danesh Kuruppu is a technical lead at WSO2, with expertise in microservices, messaging protocols and service governance. Danesh has spearheaded development of Ballerina’s standard libraries including gRPC, data and microservices framework. He has co-authored 'gRPC Up and Running' published by O’Reilly media. If you have built gRPC applications and know about the communication fundamentals, you may already know there are four fundamental communication patterns used in gRPC-based applications: simple RPC, server-side streaming, client-side streaming and bidirectional streaming. In this article, I dive deeper into these communication patterns and discuss the importance of each pattern as well as how to pick the right one, according to the use case. Before I discuss each pattern, I’ll discuss what they have in common, such as how gRPC sends messages between clients and servers over the network and how request/response messages are structured. gRPC over HTTP/2 According to official documentation, the gRPC core supports different transport protocols; however, HTTP/2 is the most common among them. In HTTP/2, communication between a client and a server happens through a single TCP connection. Within the connection, there can be multiple bidirectional flows of bytes, which are called streams. In gRPC terms, one RPC call is mapped to Continue reading