How Can I Confirm That My MongoDB Connections Are Using Change Streams Instead of Oplogs?

Question

How can I confirm that my MongoDB connections are using the Change Streams incremental sync method instead of Oplogs since upgrading my MongoDB environment version?

Environment

Connector: MongoDB

Answer

We automatically switch to using the Change Streams incremental sync method for MongoDB databases running version 6.0 or later. To verify that your connection is using the Change Streams sync method:

1. In Fivetran, go to your MongoDB connection page.
2. Go to the Settings tab.
3. Under Connection metadata & setup, click See all.
4. Look for the MongoDB version. If this shows 6.0 or higher, the connection is using the Change Streams sync method.

Alternatively, if the Fivetran Platform Connector is syncing to your destination, you can confirm that your connection uses Change Streams by checking the relevant connection's LOG table. Look for an entry in message_data like the following:

"{"event":"info","data":{"type":"update_progress","message":"Change streams total incremental updates: {inserts=0, updates=0, deletes=0, replaces=0, excludedTable=0, preImportData=0, unsupportedOperation=0, total=0}"},"created":"2025-01-01T12:00:00.200Z","connector_type":"mongo","connector_id":"test_id","connector_name":"mongo_db","connection_id":"test_id","connection_name":"test_id","sync_id":"dd0ddd00-d0dd-0d00-dd00-ddd0d00ddd0d"}"