https://github.com/asirwad/reactive-restapi-with-kafka-and-webflux

https://github.com/asirwad/reactive-restapi-with-kafka-and-webflux

apache-kafka spring-boot spring-boot-reactive webflux

Last synced: 2 months ago
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• Host: GitHub
• URL: https://github.com/asirwad/reactive-restapi-with-kafka-and-webflux
• Owner: Asirwad
• Created: 2025-03-12T10:00:22.000Z (2 months ago)
• Default Branch: main
• Last Pushed: 2025-03-12T11:27:03.000Z (2 months ago)
• Last Synced: 2025-03-12T11:28:49.918Z (2 months ago)
• Topics: apache-kafka, spring-boot, spring-boot-reactive, webflux
• Language: Java
• Homepage:
• Size: 12.7 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# 🚀 Spring Boot Kafka Reactive Project

![Java Version](https://img.shields.io/badge/Java-17+-orange)

![Kafka](https://img.shields.io/badge/Apache_Kafka-2.13-000?logo=apachekafka)

![Maven](https://img.shields.io/badge/Maven-3.8+-blueviolet)

A modern Spring Boot implementation demonstrating Kafka integration with Reactive Streams. Features real-time Wikimedia data processing with DynamoDB persistence.

## 📚 Table of Contents

- [✨ Features](#-features)

- [⚙️ Requirements](#️-requirements)

- [🚦 Getting Started](#-getting-started)

- [🧠 Key Concepts](#-key-concepts)

- [🎯 Demo Application](#-demo-application)

## ✨ Features

- Real-time data streaming from Wikimedia

- Reactive Kafka producers/consumers

- DynamoDB integration for data persistence

- Custom serialization/deserialization

- Consumer group management

- Offset tracking implementation

## ⚙️ Requirements

- ![Java](https://img.shields.io/badge/Java-17+-orange)

- ![Kafka](https://img.shields.io/badge/Apache_Kafka-3.5+-000?logo=apachekafka)

- ![Maven](https://img.shields.io/badge/Maven-3.8+-blueviolet)

## 🚦 Getting Started

### 🐳 Kafka Setup

Start Kafka Services

```bash

# Start ZooKeeper

$ bin/zookeeper-server-start.sh config/zookeeper.properties

# Start Kafka Broker (in new terminal)

$ bin/kafka-server-start.sh config/server.properties

```

### 🛠️ Project Setup

Clone and Run

```bash

$ git clone https://github.com/Asirwad/Reactive-RESTAPI-with-Kafka-and-Webflux

$ cd Reactive-RESTAPI-with-Kafka-and-Webflux

$ ./mvnw spring-boot:run

```

## 🧠 Key Concepts

📦 Kafka Architecture Overview

![Kafka Architecture](img/kafka_overview.png)

| Component       | Description                                  |

|-----------------|----------------------------------------------|

| **Producer**    | Publishes messages to topics                |

| **Consumer**    | Subscribes and processes messages          |

| **Broker**      | Manages data storage and distribution      |

| **ZooKeeper**   | Handles cluster coordination               |

🏗️ Kafka Cluster

![Kafka Cluster](img/kafka_cluster.png)

- Distributed message broker system

- Horizontal scaling capabilities

- Automatic failover handling

📮 Kafka Producer

![Producer Flow](img/kafka_producer.png)

```java

// Example Reactive Producer

public Mono> sendMessage(String topic, String message) {

    return kafkaSender.send(

        Mono.just(SenderRecord.create(topic, null, null, null, message, null))

    );

}

```

📥 Kafka Consumer

![Consumer Flow](img/kafka_consumer.png)

```java

// Example Reactive Consumer

@Bean

public ReceiverOptions receiverOptions() {

    return ReceiverOptions.create(consumerProps())

        .subscription(Collections.singleton("wikimedia.recentchange"));

}

```

📂 Topics & Partitions

![Topic Structure](img/kafka_topic.png)

| Feature         | Benefit                                      |

|-----------------|----------------------------------------------|

| Partitions      | Enable parallel processing                  |

| Replication    | Ensure data redundancy                     |

| Retention      | Configurable message persistence           |

🔢 Offsets & Consumer Groups

![Offset Management](img/kafka_offset.png)

- **Offset Tracking**: Consumer position management

- **Group Coordination**: Parallel message processing

- **Rebalancing**: Automatic partition redistribution

![Consumer Groups](img/kafka_consumer_groups.png)

## 🎯 Demo Application

### 🔥 Real-time Pipeline

![Application Flow](img/kafka_demo_application.png)

📡 Producer Implementation

**Wikimedia Stream Processor**

- Reactive HTTP client for stream consumption

- Kafka Template for message publishing

- Backpressure management

- Error handling with retries

```java

webClient.get()

    .uri("/v2/stream/recentchange")

    .retrieve()

    .bodyToFlux(String.class)

    .doOnNext(event -> kafkaTemplate.send("wikimedia.recentchange", event))

    .subscribe();

```

💾 Consumer Implementation

**DynamoDB Persistence**

- Batch record processing

- Exponential backoff strategy

- Consumer group management

- Offset commit strategies

```java

@Bean

public Consumer>> dynamoDbSaver() {

    return flux -> flux

        .bufferTimeout(100, Duration.ofMillis(500))

        .flatMap(batch -> dynamoService.saveBatch(batch))

        .subscribe();

}

```

## 🛠️ Troubleshooting

Common Issues

**⚠️ ZooKeeper Connection Problems**

- Verify zookeeper.properties configuration

- Check for port conflicts (default 2181)

**⚠️ Consumer Lag**

- Monitor with `kafka-consumer-groups.sh`

- Adjust `max.poll.records` if needed

**⚠️ Serialization Errors**

- Validate message formats

- Check key/value serializer configurations