Basics of Using CDC From Source SQL Server with AWS DMS

Basics of Using CDC From Source SQL Server with AWS DMS THERE ARE SEVERAL WAYS TO USE ONGOING REPLICATION (CHANGE DATA CAPTURE, CDC) FOR AN ON-PREMISES AND SELF-MANAGED SQL SERVER DATABASE. THESE ARE ALSO RELEVANT FOR AMAZON EC2, CLOUD-BASED DATABASES SUCH AS AMAZON RDS, OR AN AZURE SQL MANAGED INSTANCE.

 However, certain

requirements have to be met before taking up SQL Server Change Data Capt ure with SQL Server as a source for AWS DMS.  You must take a backup

before replicating data with the SQL Server configured for full backups. The recovery model should be set to Full or Bulk logged.

 Ensure that SQL Server supports backup to multiple

disks. Otherwise, if the database backup is written over multiple files on different disks, AWS DMS will not be able to read the data and the task fails.  SQL Server Replication Publisher definitions for the

source used in DMS SQL Server Change Data Capture tasks are not removed for self-managed SQL Server sources. A system administrator has to delete these definitions from the SQL Server.

 SQL Server does not capture changes (CDC) on newly-created

tables until they are published. When tables are added to the source database SQL Server, AWS DMS handles the creation of the publication. The downside here is that this process can take several minutes and all operations made to the newly created tables in this period are not captured or replicated to the target database.  Full logging must be turned on in SQL Server for AWS DMS SQL

Server Change Data Capture. This can be done by enabling MSReplication or Change Data Capture (CDC).

These limitations apply to SQL Server 2014 and later when the CDC feature was first launched.