Kafka Connect & Debezium

Introduction

Kafka Connect is a framework for connecting Kafka with external systems such as databases, key-value stores, and file systems. Debezium is an open-source distributed platform for change data capture (CDC), enabling you to stream changes from databases into Kafka.

Key Concepts

• **Kafka**: A distributed event streaming platform.
• **Kafka Connect**: A tool for scalably and reliably streaming data between Apache Kafka and other systems.
• **Debezium**: A CDC tool that captures changes in databases and streams them to Kafka.
• **Connector**: A plugin for Kafka Connect that specifies how to interact with a data source or sink.
• **Task**: A single instance of a connector that performs the actual data transfer.

Kafka Connect

Architecture

Kafka Connect consists of two main components:

1. **Source Connectors**: Import data from external systems into Kafka.
2. **Sink Connectors**: Export data from Kafka to external systems.

Example: Setting Up a Source Connector

Here’s an example of how to set up a JDBC source connector:

                {
                    "name": "jdbc-source-connector",
                    "config": {
                        "connector.class": "io.confluent.connect.jdbc.JdbcSourceConnector",
                        "tasks.max": "1",
                        "connection.url": "jdbc:mysql://localhost:3306/mydb",
                        "connection.user": "user",
                        "connection.password": "password",
                        "topic.prefix": "mysql-",
                        "poll.interval.ms": "1000",
                        "mode": "incrementing",
                        "incrementing.column.name": "id"
                    }
                }
                

Debezium

Overview

Debezium captures changes in your database and streams them to Kafka topics. It supports various databases including MySQL, PostgreSQL, MongoDB, and more.

Example: Setting Up a Debezium Connector

Below is an example of a Debezium MySQL connector configuration:

                {
                    "name": "debezium-mysql-connector",
                    "config": {
                        "connector.class": "io.debezium.connector.mysql.MySqlConnector",
                        "tasks.max": "1",
                        "database.hostname": "localhost",
                        "database.port": "3306",
                        "database.user": "debezium_user",
                        "database.password": "db_password",
                        "database.server.id": "184054",
                        "database.server.name": "dbserver1",
                        "database.whitelist": "mydb",
                        "table.whitelist": "mydb.mytable",
                        "key.converter": "org.apache.kafka.connect.json.JsonConverter",
                        "value.converter": "org.apache.kafka.connect.json.JsonConverter"
                    }
                }
                

Setup

To set up Kafka Connect and Debezium on AWS, follow these steps:

1. Launch an Amazon MSK Cluster.
2. Configure your security settings and networking (VPC, subnets).
3. Deploy Kafka Connect (Self-managed or using Amazon MSK Connect).
4. Install the Debezium connector plugin in your Kafka Connect environment.
5. Create and configure your source/sink connectors using the REST API.

Best Practices

Here are some best practices to follow when using Kafka Connect and Debezium:

• Monitor connector performance and adjust tasks based on load.
• Use offsets to track the position in the data stream.
• Implement error handling and dead letter queues for failed records.
• Regularly back up your connector configurations.
• Test your connectors in a staging environment before deploying to production.

FAQ