DMS Migration Instances

This article is part of a series on CDC in Matillion ETL

In order to use the CDC function in Matillion ETL, you must have already started a Replication Instance on your AWS account. The Migration Instance is responsible for moving data from the source to S3 and so the size of the instance can have some bearing on the performance of your CDC Tasks.

When your base CDC configuration is set (via the Manage button), Replication Instances discoverable through your chosen Credentials will become available when setting up a new CDC Task in the CDC Instance dropdown.


To create a new Replication Instance:
  1. Log into your AWS Console.
  2. Browse to the Database Migration Service.
  3. Click Replication Instances.
  4. Click Create replication instance.

On the Create replication instance screen, you can configure your new instance. However, minimal customisation is required for our purposes and we recommend leaving the default values for most options.

  • Name: An arbitrary lowercase name for your replication instance.
  • Description: An arbitrary description for your replication instance.
  • Instance class: The class (size) of your replication instance. We recommend leaving the default of dms.t2.medium but it is possible this may need to be increased for exceptionally large CDC Tasks.
  • Engine version: The replication instance's engine version. Leave this at the latest version.
  • VPC: The VPC that your Matillion ETL and CDC resources exist in.
  • Multi-AZ: Choose whether to use Multi-AZ deployments. This can be left as No.
  • Publically accessible: Choose whether the replication instance is publically available or not. For ease of use, we prefer this being left on but users may choose to turn this off.
  • Advanced: We suggest making no Advanced configurations.
  • Maintenance: We suggest making no Maintenance configurations.
When you are satisfied with the configuration, click Create replication instance. Make a note of the name you gave this instance as you may want to select it in the Matillion ETL client when creating a new CDC Task.