grpc

gRPC High-Performance RPC

Instructions

1. Assess the use case: gRPC excels at microservices, real-time streaming, and polyglot environments.
2. Follow gRPC conventions:
   • Define services in .proto files
   • Use Protocol Buffers for serialization
   • Implement proper error handling with status codes
   • Consider streaming patterns
3. Provide complete examples: Include proto definitions, server, and client code.
4. Guide on best practices: Error handling, deadlines, load balancing.

Protocol Buffers

Basic Service Definition

// user.proto
syntax = "proto3";

package user.v1;

option go_package = "github.com/myorg/myapp/gen/user/v1";

import "google/protobuf/timestamp.proto";
import "google/protobuf/empty.proto";

// User service definition
service UserService {
  // Unary RPC
  rpc GetUser(GetUserRequest) returns (User);
  rpc CreateUser(CreateUserRequest) returns (User);
  rpc UpdateUser(UpdateUserRequest) returns (User);
  rpc DeleteUser(DeleteUserRequest) returns (google.protobuf.Empty);

  // Server streaming
  rpc ListUsers(ListUsersRequest) returns (stream User);

  // Client streaming
  rpc BatchCreateUsers(stream CreateUserRequest) returns (BatchCreateResponse);

  // Bidirectional streaming
  rpc Chat(stream ChatMessage) returns (stream ChatMessage);
}

// Messages
message User {
  string id = 1;
  string email = 2;
  string name = 3;
  Role role = 4;
  google.protobuf.Timestamp created_at = 5;
  google.protobuf.Timestamp updated_at = 6;
}

message GetUserRequest {
  string id = 1;
}

message CreateUserRequest {
  string email = 1;
  string name = 2;
  string password = 3;
  Role role = 4;
}

message UpdateUserRequest {
  string id = 1;
  optional string email = 2;
  optional string name = 3;
}

message DeleteUserRequest {
  string id = 1;
}

message ListUsersRequest {
  int32 page_size = 1;
  string page_token = 2;
  UserFilter filter = 3;
}

message UserFilter {
  optional Role role = 1;
  optional string search = 2;
}

message BatchCreateResponse {
  int32 created_count = 1;
  repeated string user_ids = 2;
}

message ChatMessage {
  string user_id = 1;
  string content = 2;
  google.protobuf.Timestamp timestamp = 3;
}

enum Role {
  ROLE_UNSPECIFIED = 0;
  ROLE_USER = 1;
  ROLE_ADMIN = 2;
  ROLE_MODERATOR = 3;
}