CODEWITHSUNDEEP
mongodbamazon-web-servicesreplicationdmsaws-documentdb
PPetkov
PPetkov

Reputation: 270

AWS DMS "Load complete, replication ongoing" not working MongoDB to DocDB

I am trying to make a PoC for MongoDB to DocDB migration with DMS. I've set up a MongoDB instance with some dummy data and an empty DocDB. Source and Target endpoints are also set in DMS and both of them are connecting successfully to my databases.

When I create a migration task in DMS everything seems to be working fine. All existing data is successfully replicated from the MongoDB instance to DocDB and the migration task state is at "Load complete, replication ongoing". At this point I tried creating new entries in existing collections as well as creating new empty collections in MongoDB but nothing happens in DocDB. If I understand correctly the replication should be real time and anything I create should be replicated instantly? Also there are no indication of errors or warnings whatsoever... I don't suppose its a connectivity issue to the databases since the initial data is being replicated. Also the users I am using for the migration have admin privileges in both databases.

Does anyone have any suggestions?

Upvotes: 1

Views: 2701

Answers (2)

Perfect_Comment
Perfect_Comment

Reputation: 195

I hit the same issue. For me, the problem was that, when I enabled change streams on the source DB (as per the AWS docs), I didn't change the db_name variable in the snippet provided:

db.adminCommand({modifyChangeStreams: 1,
   database: "db_name",
   collection: "", 
   enable: true});

Upvotes: 0

Arun Kumar Thiagarajan
Arun Kumar Thiagarajan

Reputation: 66

@PPetkov - could you check the following? 1. Check if right privileges were assigned to the user in the MongoDB endpoint according to https://docs.aws.amazon.com/dms/latest/userguide/CHAP_Source.MongoDB.html. 2. Check if replicate set to capture changes was appropriately configured in the MongoDB instance. 3. Once done, try to search for "]E:" or "]W:" in the CloudWatch logs to understand if there are any noticeable failures/warnings.

Upvotes: 1

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