What Is gRPC and How It Works

gRPC (gRPC Remote Procedure Calls) is a high-performance, open-source universal RPC framework developed by Google. It’s widely used in microservice architectures to enable fast, reliable communication between services.

In this article, we’ll explore how gRPC works, how it’s different from REST, and how to implement a simple example using Protocol Buffers.

1. Why gRPC?

gRPC is designed for speed and efficiency, especially in distributed systems.

Advantages:

• Compact binary data format (Protocol Buffers)
• HTTP/2 transport: multiplexed streams and better performance
• Built-in code generation for multiple languages
• Strong typing and contracts

2. gRPC vs REST

3. How gRPC Works

Step 1: Define Service in .proto File

syntax = "proto3";

service Greeter {
  rpc SayHello (HelloRequest) returns (HelloReply);
}

message HelloRequest {
  string name = 1;
}

message HelloReply {
  string message = 1;
}

Step 2: Generate Code

Using protoc:

protoc --go_out=. --go-grpc_out=. greeter.proto

Step 3: Implement Server and Client

Example in Go:

// Server
func (s *server) SayHello(ctx context.Context, req *pb.HelloRequest) (*pb.HelloReply, error) {
  return &pb.HelloReply{Message: "Hello " + req.Name}, nil
}

4. When to Use gRPC

✅ Use gRPC if:

• You build internal microservices
• Performance and efficiency matter
• You need bi-directional streaming

❌ Avoid gRPC if:

• You build public APIs (browser support limited)
• You need human-readable responses

5. Conclusion

gRPC is a powerful alternative to REST for modern backend systems. It shines in microservice communication and delivers strong typing, performance, and scalability.

Learn it once, and use it wherever fast, efficient communication is critical.