GraphQLとgRPC
柔軟なデータ取得を可能にするGraphQLや、高性能な通信を実現するgRPCなど、代替APIスタイルについて学びます。
「GraphQLとgRPC」はCoddyKit上の無料System Design Basics for Backend Developersレッスンです。 これはレッスン2/4です。 下記で完全なレッスンを無料で読むことができます。その後、ブラウザ内の組み込みコードエディタと24時間対応のAIチューターでハンズオン演習できます。 これはSystem Design Basics for Backend Developers学習パスの一部であり、ウェブとCoddyKitアプリ全体で進捗が同期されます。 System Design Basics for Backend Developersコースには全4レッスンが含まれています。
このレッスンの一部はまだ翻訳されておらず、英語で表示されています。
Beyond REST: GraphQL & gRPC
RESTful APIs are widely used, but they aren't always the perfect fit for every scenario.
Sometimes, you need more control over data fetching or require extremely high performance for inter-service communication.
This lesson explores two powerful alternatives: GraphQL and gRPC.
REST's Data Fetching Hurdles
Traditional REST APIs often lead to two common issues:
- Over-fetching: Receiving more data than needed in a single request, wasting bandwidth.
- Under-fetching: Needing to make multiple requests to different endpoints to gather all required data.
This can be inefficient, especially for mobile clients or complex UIs.
GraphQL: Query Exactly What You Need
GraphQL is a query language for your API, and a server-side runtime for executing those queries.
It empowers clients to request precisely the data they need, eliminating over-fetching and under-fetching.
Think of it as filling out a form for your data request, rather than accepting a pre-defined bundle.
Defining Data with GraphQL Schema
Every GraphQL API is built around a schema. This schema defines all the types of data and operations (queries, mutations) available.
It acts as a contract between the client and the server, ensuring clients know exactly what they can ask for.
Here's a simple example:
type User {
id: ID!
name: String!
email: String
posts: [Post]
}
type Post {
id: ID!
title: String!
content: String
author: User!
}Fetching Data with GraphQL Queries
Clients use GraphQL queries to fetch data. They specify the exact fields they want from the available types defined in the schema.
This means a single query can replace multiple REST requests.
See how we only ask for name, email, and post titles:
query GetUserAndPosts {
user(id: "123") {
name
email
posts {
title
}
}
}Changing Data with GraphQL Mutations
Just as queries fetch data, mutations are used to modify data on the server. This includes creating, updating, or deleting records.
Mutations also return data, often the newly created or updated object, confirming the change.
Here's an example to create a new post:
mutation CreatePost($title: String!, $authorId: ID!) {
createPost(title: $title, authorId: $authorId) {
id
title
}
}gRPC: High-Performance RPC
gRPC (Google Remote Procedure Call) is an open-source framework for high-performance communication between services.
Unlike GraphQL, gRPC is more commonly used for internal microservice communication where speed, efficiency, and strict contracts are paramount.
It's built on HTTP/2 for transport and Protocol Buffers for message serialization.
Protocol Buffers: gRPC's IDL
gRPC uses Protocol Buffers (Protobuf) as its Interface Definition Language (IDL) and its underlying message interchange format.
Protobuf defines the structure of your data and the service interfaces in a language-agnostic way.
This definition is then used to generate client and server code in various languages.
syntax = "proto3";
package greeter;
service Greeter {
rpc SayHello (HelloRequest) returns (HelloReply);
}
message HelloRequest {
string name = 1;
}
message HelloReply {
string message = 1;
}gRPC: Binary, HTTP/2, Streaming
Key features of gRPC for high performance:
- HTTP/2: Enables multiplexing (multiple requests over one connection) and bidirectional streaming.
- Binary Serialization: Protobuf serializes data into a compact binary format, which is faster and smaller than JSON.
- Code Generation: Automatically generates client and server stub code from
.protodefinitions, simplifying development.
Choosing Between GraphQL & gRPC
When to use which?
- GraphQL: Ideal for flexible, client-facing APIs where clients need to define their data requirements. Excellent for mobile apps and complex UIs.
- gRPC: Best for high-performance, low-latency inter-service communication (e.g., microservices), or when strict contracts and efficient data transfer are critical.
They solve different problems and can even be used together in a larger system!
Quick Check: API Styles
Consider a scenario where you are building a new mobile application with a complex UI that needs to fetch varied data from a backend with minimal network requests. Which API style would be most suitable for the client-server communication?
Recap: Flexible & Fast APIs
In this lesson, we explored two powerful API alternatives: GraphQL and gRPC.
- GraphQL provides a flexible query language, allowing clients to fetch precisely the data they need, tackling over- and under-fetching issues.
- gRPC offers a high-performance, binary communication framework, ideal for efficient inter-service communication using HTTP/2 and Protocol Buffers.
Understanding their strengths helps you choose the right tool for different system design challenges.
よくある質問
「GraphQLとgRPC」レッスンは無料ですか？
はい。「GraphQLとgRPC」の完全なテキストはこのウェブで無料で読めます。インタラクティブに演習し（組み込みコードエディタと24時間対応のAIチューター）、System Design Basics for Backend Developersコースの残りをアンロックするには、CoddyKit PROにアップグレードしてください。 System Design Basics for Backend Developersコースには全4レッスンが含まれています。
「GraphQLとgRPC」で何を学びますか？
柔軟なデータ取得を可能にするGraphQLや、高性能な通信を実現するgRPCなど、代替APIスタイルについて学びます。 ブラウザで直接実行するハンズオンコードでSystem Design Basics for Backend Developersを演習し、24時間対応のAIチューターがレッスンを進める中での質問に答えます。
System Design Basics for Backend Developersを始めるのに経験は必要ですか？
事前経験は必要ありません。CoddyKitのSystem Design Basics for Backend Developersは初級者から上級者向けに構成されているため、ここから始めるか最初から始めて、自分のペースで進むことができます。 これはレッスン2/4です。
「GraphQLとgRPC」レッスンにはどのくらい時間がかかりますか？
ほとんどのCoddyKitレッスンは約5～10分かかります。各レッスンはコンパクトでインタラクティブなので、着実に進歩し、ウェブとアプリ全体で正確に前回の場所から再開できます。
このSystem Design Basics for Backend Developersレッスンでコードを書いて実行できますか？
はい。すべてのSystem Design Basics for Backend Developersレッスンに組み込みコードエディタが含まれているため、ブラウザでリアルコードを書いて実行し、即座のAIフィードバックを取得できます。ローカル設定は不要です。