Advanced Spring Boot 4: Event-Driven Architecture (Kafka) · レッスン

Sleuth/Zipkinによる分散トレーシング

Spring Cloud SleuthとZipkinを使用して分散トレーシングを実装し、複数のマイクロサービスにまたがるイベントの流れを追跡します。

「Sleuth/Zipkinによる分散トレーシング」はCoddyKit上の無料Advanced Spring Boot 4: Event-Driven Architecture (Kafka)レッスンです。これはレッスン3/4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Advanced Spring Boot 4: Event-Driven Architecture (Kafka)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。 Advanced Spring Boot 4: Event-Driven Architecture (Kafka)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。

Why Trace Distributed Systems?

In a microservices architecture, a single user request often travels through many different services. This distributed nature makes it incredibly hard to track the flow of requests and pinpoint where issues occur.

Distributed tracing helps you visualize the full journey of a request across all services involved, making debugging and performance monitoring much easier.

Trace and Span: Your Navigation Tools

Distributed tracing relies on two core concepts:

Trace: Represents the complete journey of a request through a system, from start to finish. It's like a story of one operation.
Span: A single, logical unit of work within a trace. Each operation (e.g., an HTTP request, a database call, sending a Kafka message) gets its own span. Spans have parent-child relationships, showing cause and effect.

Meet Spring Cloud Sleuth

Spring Cloud Sleuth is a powerful library for Spring Boot applications that automatically adds distributed tracing capabilities. It instruments your application to generate, collect, and propagate trace information.

It automatically adds trace and span IDs to your logs.
It propagates these IDs across service boundaries (HTTP, messaging, etc.).

This means you don't have to manually manage trace IDs in most cases!

Getting Started: Add Sleuth & Zipkin

To integrate Spring Cloud Sleuth into your Spring Boot project, add the following dependencies to your pom.xml:

spring-cloud-starter-sleuth: The core tracing library.
spring-cloud-sleuth-zipkin: Integrates with Zipkin for trace visualization.

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-sleuth</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-sleuth-zipkin</artifactId>
</dependency>

Minimal Sleuth Configuration

After adding the dependencies, a minimal configuration in your application.properties is usually enough to get started. Sleuth will automatically detect and configure itself.

To send traces to a Zipkin server, specify its URL:

spring.application.name=my-kafka-producer-app
spring.zipkin.base-url=http://localhost:9411
spring.sleuth.sampler.probability=1.0

Tracing Across Kafka Messages

One of Sleuth's key features is its ability to propagate trace context across messaging systems like Kafka. When you use Spring's KafkaTemplate to send messages:

Sleuth automatically injects trace and span IDs into the Kafka message headers.
When a @KafkaListener receives the message, Sleuth extracts these headers and continues the trace, linking the producer's span to the consumer's span.

This creates a continuous trace, even across asynchronous Kafka message flows.

Zipkin: See Your Traces

While Sleuth generates and propagates trace data, Zipkin is the distributed tracing system that collects, stores, and visualizes this data. It provides a user interface where you can:

Search for traces by service name, timestamp, or trace ID.
View a Gantt chart representation of a trace, showing the sequence and duration of spans.
Identify performance bottlenecks and errors across your microservices.

Spin Up Zipkin Locally

For local development and testing, you can easily run a Zipkin server using Docker. This provides a quick way to see your traces without complex setup.

docker run -d -p 9411:9411 openzipkin/zipkin

Producer with Sleuth Instrumentation

Here's a simple Spring Boot Kafka producer. With Sleuth and Zipkin configured (as shown in earlier scenes), when you run this, Sleuth will automatically add tracing headers to the Kafka message. You would see the traceId and spanId in your application logs and in the Zipkin UI.

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@RestController
public class SleuthKafkaProducerApplication {

    @Autowired
    private KafkaTemplate<String, String> kafkaTemplate;

    private static final String TOPIC = "my-traceable-topic";

    public static void main(String[] args) {
        SpringApplication.run(SleuthKafkaProducerApplication.class, args);
    }

    @GetMapping("/send")
    public String sendMessage(@RequestParam("message") String message) {
        kafkaTemplate.send(TOPIC, message);
        return "Message sent with trace context: " + message;
    }
}

Quick Check: Tracing Concepts

When a Spring Boot application with Spring Cloud Sleuth sends a message to Kafka, which of the following statements are true about trace information?

Lesson Summary: Tracing Your Flow

You've learned about distributed tracing, a critical technique for understanding complex microservice interactions. We covered:

The concepts of Trace (full request journey) and Span (individual operation).
How Spring Cloud Sleuth automatically instruments Spring Boot applications, including Kafka producers and consumers, to propagate tracing context.
The role of Zipkin in collecting and visualizing these traces, providing invaluable insights into your system's behavior.

With these tools, you can effectively monitor and debug your event-driven microservices!

よくある質問

「Sleuth/Zipkinによる分散トレーシング」レッスンは無料ですか？

はい。「Sleuth/Zipkinによる分散トレーシング」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）、Advanced Spring Boot 4: Event-Driven Architecture (Kafka)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。 Advanced Spring Boot 4: Event-Driven Architecture (Kafka)コースには全4レッスンが含まれています。

「Sleuth/Zipkinによる分散トレーシング」で何を学びますか？

Spring Cloud SleuthとZipkinを使用して分散トレーシングを実装し、複数のマイクロサービスにまたがるイベントの流れを追跡します。ブラウザで直接実行するハンズオンコードでAdvanced Spring Boot 4: Event-Driven Architecture (Kafka)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。

Advanced Spring Boot 4: Event-Driven Architecture (Kafka)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Advanced Spring Boot 4: Event-Driven Architecture (Kafka)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3/4です。

「Sleuth/Zipkinによる分散トレーシング」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Advanced Spring Boot 4: Event-Driven Architecture (Kafka)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Advanced Spring Boot 4: Event-Driven Architecture (Kafka)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。

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