gRPC: Up and Running

Chapter 3. gRPC Communication Patterns

In the first couple of chapters, you learned the basics of gRPC’s inter-process communication techniques and got some hands-on experience in building a simple gRPC-based application. So far what we have done is define a service interface, implement a service, run a gRPC server, and invoke service operations remotely through a gRPC client application. The communication pattern between the client and the server is a simple request–response style communication, where you get a single response for a single request. However, with gRPC, you can leverage different inter-process communication patterns (or RPC styles) other than the simple request–response pattern.

In this chapter, we’ll explore four fundamental communication patterns used in gRPC-based applications: unary RPC (simple RPC), server-side streaming, client-side streaming, and bidirectional streaming. We’ll use some real-world use cases to showcase each pattern, define a service definition using a gRPC IDL, and implement both the service and client side using Go.

Note

Go and Java Code Samples

To maintain consistency, all the code samples in this chapter are written using Go. But if you are a Java developer, you can also find the complete Java code samples for the same use cases in the source code repository for this book.

Simple RPC (Unary RPC)

Let’s begin our discussion on gRPC communication patterns with the simplest RPC style, simple RPC, which is also known as unary RPC. In simple ...