On-Premises to AWS: A Detailed Guide on Copying CDC Data from MySQL to AWS RDS MySQL

Rohan Pathak
3 min readJun 29, 2023

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Welcome! If you’ve landed here, you’re probably looking to understand how to replicate Change Data Capture (CDC) from an On-Premises MySQL database to AWS RDS MySQL. In this article, we will go through this process in a detailed yet digestible manner. So, whether you’re a seasoned database administrator or just starting to dip your toes into the world of cloud databases, you’re in the right place!

Introduction: Understanding CDC and its Importance

Change Data Capture (CDC) is a design pattern that captures individual data changes instead of dealing with the entire batch of data. It is used in scenarios where we need to ensure data synchronicity between our source (in this case, On-Premises MySQL) and target (AWS RDS MySQL) databases.

CDC is crucial in situations where you want to migrate to a new system, replicate data across multiple systems, or maintain an up-to-date backup.

Now that we’ve established what CDC is, let’s delve into the process of replicating this data from your On-Premises MySQL to AWS RDS MySQL.

Tools You’ll Need: AWS DMS

We’ll be using AWS Database Migration Service (DMS) to perform the replication. AWS DMS is a managed service that allows you to migrate your databases to AWS quickly and securely. The source database remains operational during the migration, minimizing downtime.

Now, let’s get into the actual steps.

Step 1: Setting up your AWS DMS

Firstly, you need to set up your AWS DMS to start the migration process.

To do this, go to the AWS Management Console, navigate to DMS, and select “Replication instances”. Click on “Create replication instance” and fill out the necessary details. This replication instance performs the actual data migration and continuous data replication.

Step 2: Define Source and Target Endpoints

In DMS, you need to define where the data is coming from (source endpoint) and where it’s going (target endpoint). In our case, the source is your On-Premises MySQL database, and the target is AWS RDS MySQL.

Navigate to “Endpoints” in DMS, and add a new endpoint for both your source and target databases. You will need to provide details such as server name, port, SSL mode, username, and password.

Make sure to test the connection before moving to the next step.

Step 3: Create a Replication Task

Once your endpoints are defined, you need to create a replication task. This task will specify what data you want to migrate and the type of migration.

Under the “Database migration tasks” section in DMS, click on “Create task”. Assign a task identifier, select your source and target endpoints, and your migration type. Choose “Migrate existing data and replicate ongoing changes” to enable CDC.

Step 4: Table Mapping

While creating the task, you’ll need to define Table mappings. This specifies the schemas, tables, and specific data to be migrated. You can choose to migrate everything or select specific schemas and tables.

Once you’ve completed this step, click “Create task”. AWS DMS will now start the task of migrating your data from the source to the target endpoint.

Step 5: Monitoring Your Task

AWS DMS provides comprehensive monitoring through CloudWatch. You can view the metrics for your tasks, endpoints, and replication instances, enabling you to closely monitor the process and ensure everything is running smoothly.

Conclusion: Migrating and More

And there you have it! You’ve set up Change Data Capture (CDC) from your On-Premises MySQL to AWS RDS MySQL. AWS DMS makes this process relatively straightforward while ensuring your data is securely transferred.

Remember, the beauty of AWS DMS is not only in database migration but also in continuous data replication, making it a powerful tool for real-time analytics and synchronization between various environments.

In the next guide, we will dive deeper into optimizing and automating this process, so stay tuned! Happy migrating!

For a more in-depth technical yet Free-Of-Cost digest, feel free to reach out to me at LinkedIn: www.linkedin.com/in/rohan-pathak-81568b145

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