Understanding gRPC: Google’s High-Performance RPC Framework

In the world of distributed systems and microservices, efficient communication between services is critical. That’s where gRPC comes in—a high-performance, open-source Remote Procedure Call (RPC) framework originally developed by Google and now maintained by the Cloud Native Computing Foundation (CNCF).

gRPC is designed to make inter-service communication fast, lightweight, secure, and language-agnostic, making it a powerful tool for modern software architectures.

gRPC boilerplate

This boilerplate covers gRPC implementation and the use of Evans client

• https://github.com/stack-boilerplates/go-grpc

Why gRPC?

gRPC shines in scenarios where performance and scalability are key:

• Microservices: Ideal for internal service-to-service communication.
• Mobile & Backend: Works well across platforms, though gRPC-Web is still maturing.
• Automatic Code Generation: Client and server stubs are generated from .proto files.
• Streaming Support: Binary, bidirectional streaming over a single HTTP/2 connection.

Official support includes:

• gRPC-Go
• gRPC-Java
• gRPC-C (C, C++, Python, Ruby, Objective-C, PHP, C#, Node.js, Dart, Kotlin)

Protocol Buffers (Protobuf)

At the heart of gRPC is Protocol Buffers, a language-neutral, platform-neutral, extensible mechanism for serializing structured data.

Unlike JSON, Protobuf is binary, which means:

JSON (Human-readable)	Protocol Buffers (Binary)
Larger payload	Smaller payload
Higher CPU usage	Lower CPU usage
More network overhead	Less network overhead
Slower processing	Faster processing

Example .proto Schema

This schema defines the contract between client and server, ensuring both sides understand the structure of the data being exchanged.

syntax = "proto3";

message SearchRequest {
  string query = 1;
  int32 page_number = 2;
  int32 request_per_page = 3;
}

Communication Models with HTTP/2

gRPC uses HTTP/2, which brings several advantages:

• Multiplexing: Multiple requests over a single TCP connection.
• Binary framing: Faster and more efficient than text-based HTTP/1.1.
• Server Push: Server can proactively send data to clients.
• Header Compression: Reduces overhead and latency.

gRPC Communication Types

• Unary RPC: Single request, single response.
• Server Streaming: Single request, multiple responses.
• Client Streaming: Multiple requests, single response.
• Bidirectional Streaming: Continuous two-way communication.

REST vs gRPC comparison

Feature	REST	gRPC
Data Format	JSON / Text	Protocol Buffers (Binary)
Communication	Unidirectional	Bidirectional & Async
Latency	Higher	Lower
Contract	Optional	Required (.proto files)
Streaming Support	No	Yes
Design Constraints	Predefined (HTTP verbs)	Flexible
Tooling	Third-party libs	Native + Code Generation