Migrate Cosmos DB to Mongo Atlas

Hello there! We want to migrate from Cosmos DB to Mongo Atlas.

We want to use the live migration tool.
We’re not able to validate the source due to Atlas not being able to resolve its host:


However, when using Mongo Shell we’re able to connect without issues:

Cosmos DB specs:

  • 1 shard
  • Public Access
  • Needed IPs added to Firewall

The deployment created in Atlas has the same specs as the source.

How do we solve this? Is there something we are missing?
We need this to work to have a live replication during the migration and prevent data loss.

Hi @craftechio_green, welcome to community forums!

I saw that your problem is more related to the connection, however, Live Migrator does not support migrations with CosmosDB as the source because this requires Oplog, which CosmosDB does not have.

The strategy is to import/export or use a tool like Apache Kafka to reduce the impact of downtime. See this link: Migrate from Azure CosmosDB to MongoDB Atlas Using Apache Kafka | MongoDB

I hope it helps you!



Hi @Leandro_Domingues, thank you for your reply!

Ok, we’ll try with that and let you know how it went.

I’ll mark it as the solution.

Have a great weekend!

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