What are the core features and advantages of gRPC? Why choose gRPC over other RPC frameworks?

gRPC is a high-performance RPC framework open-sourced by Google, built on HTTP/2 and Protobuf, with the following core features and advantages:

Core Features:

1. Based on HTTP/2

• Multiplexing: Single TCP connection can send multiple requests simultaneously, reducing connection overhead
• Binary Framing: More efficient than HTTP/1.x text format
• Header Compression: Uses HPACK algorithm to compress headers, reducing transmitted data
• Server Push: Supports server-initiated data push
• Streaming: Supports unidirectional and bidirectional streaming

2. Based on Protobuf

• Efficient Serialization: Binary format, fast serialization/deserialization
• Strong Typing: Defines interfaces through .proto files, compile-time type checking
• Cross-language: Supports 10+ programming languages
• Backward Compatibility: Field numbering mechanism ensures version compatibility

3. Four Service Modes

• Unary RPC: Client sends one request, server returns one response
• Server Streaming RPC: Client sends one request, server returns streaming response
• Client Streaming RPC: Client sends streaming request, server returns one response
• Bidirectional Streaming RPC: Both client and server can send streaming data

Advantages:

1. High Performance

• HTTP/2 multiplexing reduces connection overhead
• Protobuf binary serialization is efficient
• Supports streaming transmission, suitable for big data scenarios

2. Low Latency

• Binary protocol reduces parsing time
• Multiplexing avoids head-of-line blocking
• Connection reuse reduces handshake overhead

3. Cross-language Support

• Automatically generates client and server code in multiple languages
• Unified Interface Definition Language (IDL)
• Seamless integration of services in different languages

4. Strong Typing and Code Generation

• Compile-time type checking reduces runtime errors
• Automatic code generation improves development efficiency
• Good IDE support, excellent development experience

5. Streaming Communication

• Supports real-time data transmission
• Suitable for chat, push, real-time monitoring scenarios
• Reduces request-response round trips

6. Bidirectional Streaming Support

• Both client and server can send data simultaneously
• Suitable for real-time collaboration, gaming scenarios
• Reduces connection establishment overhead

7. Complete Ecosystem

• Interceptor mechanism
• Load balancing
• Service discovery
• Distributed tracing integration

Applicable Scenarios:

• Internal microservice communication
• Real-time data stream processing
• Cross-language service calls
• High-performance requirement scenarios
• Applications requiring streaming communication

Code Example:

protobuf
// Define service
service Greeter {
  rpc SayHello (HelloRequest) returns (HelloReply) {}
  rpc SayHelloStream (HelloRequest) returns (stream HelloReply) {}
}

// Define messages
message HelloRequest {
  string name = 1;
}

message HelloReply {
  string message = 1;
}