You can't use Aurora MySQL replicas as a source for AWS DMS unless your DMS migration task mode is Migrate existing data—full load only.

0

We would like to use Aurora MySQL replicas as a source for an AWS DMS task with type "migrate existing data and replicate ongoing changes", as we're afraid of having problems in our prod database which we are using as the source now. I saw in the documentation that is only supported for "Migrate existing data—full load only", but would like to know exactly what is the technical limitation that prevents that from being possible and if you are planning to make it possible someday. Is there any provider/service besides DMS that would allow us to migrate from Aurora MySQL replicas to Redshift? Which? Any suggestion is welcome as long as it allows us to replicate "ongoing changes" in near real time.

Thanks!

2 Answers
0

for change data capture to work AWS DMS would require to read binlogs which holds information about transactions. With Aurora MySQL reader endpoint Binlogs are not accessible thus cdc wont work.

AWS
answered a year ago
  • Does this logic applies to RDS MySQL Read Replica as well?

0

DMS uses binlogs in MySQL for CDC. In Aurora MySQL, the readers do not use binlogs for replication replication. [+] https://docs.aws.amazon.com/dms/latest/userguide/CHAP_Source.MySQL.html#CHAP_Source.MySQL.Limitations

Since aurora has a shared volume which is shared by the all the readers and the writer, the changes are directly made to the volume. Reader then reads the data directly from the volume. [+] https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/Aurora.Overview.html

Since reader instances in aurora do not have any binlogs as the write queries never reach the reader instance, CDC task will not be able to replicate the ongoing changes from the reader instance to your redshift database.

As an alternative, you can choose to create an Aurora read replica for your cluster and then use the writer instance of the replica cluster for the CDC task. Since RDS MySQL read replicas and the Aurora read replicas uses binlog for replicating changes from source cluster/instance, you should be able to setup CDC task from read replicas.

"If you are using an Amazon RDS MySQL or Amazon RDS MariaDB read replica as a source, enable backups on the read replica, and ensure the log_slave_updates parameter is set to TRUE." [+] https://docs.aws.amazon.com/dms/latest/userguide/CHAP_Source.MySQL.html#CHAP_Source.MySQL.AmazonManaged

AWS
SUPPORT ENGINEER
Rajan_L
answered a year ago

You are not logged in. Log in to post an answer.

A good answer clearly answers the question and provides constructive feedback and encourages professional growth in the question asker.

Guidelines for Answering Questions