WebSockets & Real-Time Systems with Spring · レッスン

RabbitMQ/Kafkaとの統合

サーバー間通信に外部メッセージブローカーを使用するようSpring WebSocketsを設定します。

「RabbitMQ/Kafkaとの統合」はCoddyKit上の無料WebSockets & Real-Time Systems with Spring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WebSockets & Real-Time Systems with Spring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。 WebSockets & Real-Time Systems with Spring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。

Scaling with External Brokers

When your WebSocket application runs on multiple server instances, an in-memory message broker isn't enough. You need an external message broker to coordinate messages across all instances.

This ensures that a message sent to one server can be received by a client connected to *any* server in your cluster, enabling true horizontal scaling.

Spring's Broker Bridge

Spring provides a powerful abstraction called the STOMP Broker Relay. This allows your Spring WebSocket application to delegate message routing to an external STOMP-compatible message broker.

Your application acts as a client to the external broker, sending and receiving messages on behalf of connected WebSocket clients.

RabbitMQ: A STOMP Broker

RabbitMQ is a popular open-source message broker that can be configured to act as a STOMP broker by enabling its STOMP plugin. This makes it an excellent choice for scaling Spring WebSocket applications.

Producers: Your Spring app sends messages to RabbitMQ.
Consumers: Your Spring app receives messages from RabbitMQ.
STOMP Plugin: Translates WebSocket STOMP frames to AMQP and vice-versa.

Add RabbitMQ Dependency

To enable Spring to communicate with RabbitMQ, you need to add the spring-boot-starter-websocket and spring-boot-starter-amqp dependencies to your project's build.gradle or pom.xml.

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-websocket'
    implementation 'org.springframework.boot:spring-boot-starter-amqp'
    // ... other dependencies
}

Configure RabbitMQ Broker Relay

In your WebSocketConfig, use enableStompBrokerRelay() to tell Spring to use RabbitMQ's STOMP plugin as the message broker. Remember to set the correct host, port, and credentials.

Try running this full Spring Boot application:

package com.coddykit.websocket;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Configuration;
import org.springframework.messaging.simp.config.MessageBrokerRegistry;
import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
import org.springframework.web.socket.config.annotation.WebSocketMessageBrokerConfigurer;
import org.springframework.web.socket.config.annotation.StompEndpointRegistry;

@SpringBootApplication
public class Main {
    public static void main(String[] args) {
        SpringApplication.run(Main.class, args);
        System.out.println("Spring Boot WebSocket app with RabbitMQ broker relay started.");
        System.out.println("Ensure RabbitMQ with STOMP plugin is running on localhost:61613.");
    }

    @Configuration
    @EnableWebSocketMessageBroker
    static class WebSocketConfig implements WebSocketMessageBrokerConfigurer {

        @Override
        public void configureMessageBroker(MessageBrokerRegistry config) {
            config.enableStompBrokerRelay("/topic", "/queue")
                  .setRelayHost("localhost") // Or your RabbitMQ host
                  .setRelayPort(61613) // Default STOMP port for RabbitMQ plugin
                  .setClientLogin("guest")
                  .setClientPasscode("guest");
            config.setApplicationDestinationPrefixes("/app");
            config.setUserDestinationPrefix("/user");
        }

        @Override
        public void registerStompEndpoints(StompEndpointRegistry registry) {
            registry.addEndpoint("/ws").withSockJS();
        }
    }
}

Kafka for Inter-Server Sync

While RabbitMQ can act as a direct STOMP broker relay, Apache Kafka is typically used for different types of inter-server communication in a scalable WebSocket architecture.

Instead of Kafka being the direct STOMP broker, individual Spring WebSocket instances might use Kafka to broadcast internal events or messages to other instances in the cluster.

Kafka's Role in a Cluster

Imagine you have multiple WebSocket servers. When a message arrives at Server A, and the recipient is connected to Server B, Server A can publish the message to a Kafka topic.

Server B (and all other servers) can consume from this topic, identify the message for its client, and forward it. This makes Kafka an excellent backend for distributed message coordination.

Add Kafka Dependency

To enable Spring to interact with Kafka for backend messaging, you need the spring-kafka dependency.

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-websocket'
    implementation 'org.springframework.kafka:spring-kafka'
    // ... other dependencies
}

Kafka Application Properties

When using Kafka for inter-server messaging, you'd configure Kafka broker details and consumer/producer properties in your application.properties file.

spring.kafka.bootstrap-servers=localhost:9092
spring.kafka.producer.key-serializer=org.apache.kafka.common.serialization.StringSerializer
spring.kafka.producer.value-serializer=org.apache.kafka.common.serialization.StringSerializer
spring.kafka.consumer.group-id=websocket-cluster
spring.kafka.consumer.key-deserializer=org.apache.kafka.common.serialization.StringDeserializer
spring.kafka.consumer.value-deserializer=org.apache.kafka.common.serialization.StringDeserializer

Broker Configuration Check

You're setting up a Spring Boot WebSocket application to use an external STOMP-compatible message broker to support multiple server instances. Which method in WebSocketMessageBrokerConfigurer is primarily used to configure Spring to connect to this external broker?

Recap: External Brokers

We've learned how external message brokers are crucial for scaling WebSocket applications. Spring's enableStompBrokerRelay() simplifies integrating with brokers like RabbitMQ (when its STOMP plugin is enabled).

For Kafka, while not a direct STOMP broker relay, it serves as a powerful backend for inter-server communication, allowing WebSocket instances to coordinate and distribute messages across a cluster, enabling robust scaling.

よくある質問

「RabbitMQ/Kafkaとの統合」レッスンは無料ですか？

はい。「RabbitMQ/Kafkaとの統合」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）、WebSockets & Real-Time Systems with Spring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。 WebSockets & Real-Time Systems with Springコースには全4レッスンが含まれています。

「RabbitMQ/Kafkaとの統合」で何を学びますか？

サーバー間通信に外部メッセージブローカーを使用するようSpring WebSocketsを設定します。ブラウザで直接実行するハンズオンコードでWebSockets & Real-Time Systems with Spring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。

WebSockets & Real-Time Systems with Spring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WebSockets & Real-Time Systems with Spring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。

「RabbitMQ/Kafkaとの統合」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WebSockets & Real-Time Systems with Spring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WebSockets & Real-Time Systems with Spring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。

このコースのすべてのレッスン

← WebSockets & Real-Time Systems with Springに戻る