Why gRPC Is the Go-To RPC Framework for Multi-Language Backend Services

Background

In the current cloud‑native era, RPC services are a core internet technology, and many well‑known RPC frameworks have emerged, among which gRPC is the focus of this article.

The author, a C++ intern at JD, noticed differences between C++ and Java and decided to analyze gRPC and compare it with other mainstream RPC frameworks.

Comparison

1. gRPC Implementation Principle

In gRPC, the client application can invoke methods on a remote server as if they were local objects. A service is defined with methods that can be called remotely; the server implements the interface and runs a gRPC server, while the client holds a stub that provides the same methods.

gRPC client and server can run in diverse environments, and developers can use any officially supported language, e.g., Java for the server and Ruby, Go, Python for the client.

2. Advantages and Disadvantages

2.1 Advantages

2.1.1 Multi‑Language Support

gRPC officially supports many languages, including C#/.NET, C++, Dart, Go, Java, Kotlin, Node.js, Objective‑C, PHP, Python, Ruby, allowing developers to choose the best language for each component.

2.1.2 Based on Protocol Buffers

gRPC uses Protocol Buffers as its IDL and binary message format, providing language‑neutral definitions and smaller binary payloads compared with JSON.

Key syntax examples:

message Person {
  required string name = 1;
  optional int32 id = 2;
  repeated string email = 3;
}
enum PhoneType {
  MOBILE = 0;
  HOME = 1;
  WORK = 2;
}
service HelloService {
  rpc SayHello (HelloRequest) returns (HelloReply) {}
}

2.1.3 Cross‑Platform Compatibility

gRPC runs on various operating systems, mobile devices, and web environments.

2.1.4 Underlying Transport Protocol

gRPC uses HTTP/2, which provides binary framing, compression, and multiplexing over a single TCP connection, eliminating head‑of‑line blocking.

2.1.5 Strong Community and Ecosystem

The ecosystem offers extensive documentation, tutorials, and API references, and many projects such as Dubbo3, gRPC‑Swift, and gRPC‑Spring add support for additional languages.

2.1.6 Strict Specification

Unlike loosely defined JSON‑HTTP APIs, gRPC follows a formal specification that standardizes service definitions across platforms.

2.2 Disadvantages

2.2.1 Limited Browser Support

Browsers cannot directly call gRPC services because gRPC heavily relies on HTTP/2 features that browsers do not expose.

2.2.2 Not Human‑Readable

gRPC messages are encoded in binary protobuf format, which is efficient but not human‑readable without additional tooling.

3. Demo

The author demonstrates cross‑language RPC calls using C++ and Go.

Project structure:

grpc-demo
├── cpp
│   ├── CMakeLists.txt
│   ├── cmake
│   │   └── common.cmake
│   ├── include
│   ├── proto
│   │   └── helloworld.proto
│   └── src
│       └── main.cpp
├── go
│   ├── Makefile
│   ├── go.mod
│   ├── proto
│   │   └── helloworld.proto
│   ├── service
│   └── src
│       └── main
│           └── main.go
└── proto
    └── helloworld.proto

Source code is available at https://github.com/ConstantineQAQ/grpc-demo.

Conclusion

Because of its extensibility, lightweight transport format, and strong community support, gRPC is increasingly chosen by enterprises, and the author hopes future applications will leverage gRPC to combine the strengths of multiple languages.