Migrating MongoDB clusters

To migrate your MongoDB database to Yandex StoreDoc, follow these steps: transfer the data, switch the legacy database to read-only mode, transfer the workload over to the Yandex Cloud database cluster.

Using Data Transfer for migration allows you to:

• Migrate your database with zero downtime.
• Migrate from older to newer versions of MongoDB.
• Eliminate the need for an intermediate VM or for exposing your Yandex StoreDoc target cluster to the internet.

For more information, see Problems addressed by Yandex Data Transfer.

To use this migration method, enable internet access to the source cluster.

Required paid resourcesRequired paid resources

• Yandex StoreDoc cluster: computing resources allocated to hosts, storage and backup size (see Yandex StoreDoc pricing).
• Public IP addresses if public access is enabled for cluster hosts (see Virtual Private Cloud pricing).
• Each transfer: use of computing resources and the number of transferred data rows (see Data Transfer pricing).

Getting startedGetting started

Create a Yandex StoreDoc target cluster with computing capacity and storage size matching the source database’s environment.

The source and target database names must be the same.

Transferring dataTransferring data

1. Prepare the source cluster.

2. Prepare the target cluster.

3. Create a source endpoint with the following settings:

   • Database type: MongoDB.

   • Endpoint parameters → Connection settings: Custom installation.

     Configure the source cluster connection settings.

   Note

   Transferring of Time Series collections is not supported, so you should exclude such collections in the endpoint settings.

4. Create a target endpoint with the following settings:

   • Database type: MongoDB.

   • Endpoint parameters → Connection settings: Yandex StoreDoc cluster.

     Specify the target cluster ID.

5. Create a transfer of the Snapshot and increment type that will use the new endpoints.

   To make large collections (over 1 GB) copy more quickly, enable parallel copy in the transfer settings. Specify two or more workers. The collection will be split into the specified number of parts that will be copied concurrently.

   For parallel copy to work, the _id fields in all documents within the collection must have the same data type. If a transfer detects a type mismatch, the collection will not be split but transferred in a single thread instead. If needed, remove documents with mismatched data types from the collection prior to transfer.

   Note

   If a document with a different data type is added to the collection after the transfer starts, the transfer will migrate it at the replication stage after parallel copying. However, when reactivated, the transfer will not be able to split the collection into parts, since the requirement for the same _id field type in all documents of the collection will not be met.

6. Activate the transfer.

7. Wait for the transfer status to change to Replicating.

8. Switch the source cluster to "read-only" mode and move the workload to the target cluster.

9. On the transfer monitoring page, wait until the Maximum data transfer delay value drops to zero. This means that all changes made in the source cluster after the initial data copy have been transferred to the target cluster.

10. Deactivate the transfer and wait for its status to change to Stopped.

    For more information about transfer statuses, see Transfer lifecycle.

11. Ensure the transfer is stopped, then delete it.

12. Delete the source and target endpoints.

Useful linksUseful links

For other migration methods, see this Yandex StoreDoc guide.