Problems with MongoDB Atlas and AWS DMS


I have a problem that I really don’t know how to solve or what approach to take. For data analysis and other similar things I need to use the AWS data migration service to migrate data from mongoDB to an AWS Redshift, but when I run the migration task I always get an error: “Unable to find transaction: …” . This process reads the oplog of the replica set. I have seen that this problem only occurs in certain collections not in all but I can’t find the possible cause. Any ideas?


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I have a developer having a similar issue where they’re trying to connect MongoDB Atlas to S3 via AWS DMS

They got this error:

Test Endpoint failed: Application-Status: 1020912, Application-Message: Failed to create new client connection Failed to connect to database., Application-Detailed-Message: Error verifying connection

But looking at the AWS documentation, looks like AWS doesn’t support MongoDB Atlas yet with AWS DMS? Or am I mistaken? What’s the best course of action here?

Hello mates,

I was able to perform cdc once. However, I’ve deleted my replication instance and now I’m currently not able to establish the database connection again.

Let me know in case you accomplish it, please.


Hi Chris,

At this moment I have some DMS task working fine with MongoDB Atlas, so I suppose you have another problem. I have a problem with some specific mongo collections but I can connect with Mongo Atlas.

In your case I would check the DMS connection config and the mongoDB Atlas security config

Hi Diego,

Do you have another mongoDb replicaset or you only have removed the replication instance?. DMS needs a mongo log with name “oplog”, this log is created when you have a mongodb replicaset, without this log I dont think DMS works