Migrate data from a standalone MongoDB instance to a replica set or sharded cluster instance

Precautions

• During full data migration, DTS uses read and write resources of the source and destination databases. This may increase the load of the database server. If you migrate a large volume of data or the server specifications cannot meet your requirements, database services may become unavailable. Before you migrate data, evaluate the impact of data migration on the performance of the source and destination databases. We recommend that you migrate data during off-peak hours.
• DTS does not support incremental data migration from a standalone instance. To ensure data consistency, do not write data to the source instance during full data migration.
• If the source and destination ApsaraDB for MongoDB instances have different versions or storage engines, make sure that the versions or storage engines are compatible. For more information, see MongoDB versions and storage engines.

Billing

Migration types

Full data migration: DTS migrates all historical data of the required objects from the source MongoDB database to the destination MongoDB database.

Permissions required for database accounts

For more information about how to create and authorize a database account, see Use DMS to manage MongoDB users.

Procedure

1. Log on to the DTS console.
2. In the left-side navigation pane, click Data Migration.
3. At the top of the Migration Tasks page, select the region where the destination ApsaraDB for MongoDB instance resides.
   
4. In the upper-right corner of the page, click Create Migration Task.
5. Configure the source and destination databases for the data migration task.
   

   Section	Parameter	Description
   N/A	Task Name	DTS automatically generates a task name. We recommend that you specify an informative name for easy identification. You do not need to use a unique task name.
   Source Database	Instance Type	Select ApsaraDB for MongoDB.
   	Instance Region	Select the region where the source ApsaraDB for MongoDB instance resides.
   	MongoDB Instance ID	Select the ID of the source ApsaraDB for MongoDB instance.
   	Database Name	Enter the name of the authentication database. The database account is created in this database. Note If the database account is root, enter admin.
   	Database Account	Enter the database account of the source ApsaraDB for MongoDB instance. For more information about the permissions that are required for the account, see Permissions required for database accounts.
   	Database Password	Enter the password of the source database account. Note After you specify the source database parameters, click Test Connectivity next to Database Password to verify whether the specified parameters are valid. If the specified parameters are valid, the Passed message appears. If the Failed message appears, click Check next to Failed. Modify the source database parameters based on the check results.
   Destination Database	Instance Type	Select MongoDB Instance.
   	Instance Region	Select the region where the destination ApsaraDB for MongoDB instance resides.
   	MongoDB Instance ID	Select the ID of the destination ApsaraDB for MongoDB instance.
   	Database Name	Enter the name of the authentication database. The database account is created in this database. Note If the database account is root, enter admin.
   	Database Account	Enter the database account of the destination ApsaraDB for MongoDB instance. For more information about the permissions that are required for the account, see Permissions required for database accounts.
   	Database Password	Enter the password of the destination database account. Note After you specify the destination database parameters, click Test Connectivity next to Database Password to verify whether the specified parameters are valid. If the specified parameters are valid, the Passed message appears. If the Failed message appears, click Check next to Failed. Modify the destination database parameters based on the check results.

6. In the lower-right corner, click Set Whitelist and Next.
   Note DTS adds the CIDR blocks of DTS servers to the whitelists of the source and destination ApsaraDB for MongoDB instances. This ensures that DTS servers can connect to the source and destination ApsaraDB for MongoDB instances. After data migration is complete, you can remove the CIDR blocks of DTS servers from the whitelists. For more information, see Configure a whitelist for a sharded cluster instance.
7. Select the migration types and objects to be migrated.
   

   Parameter	Description
   Migration Types	Select Full Data Migration. Note If the data source is a standalone instance, you can select only Full Data Migration. To ensure data consistency, do not write data to the source instance during full data migration.
   Objects	Select objects from the Available section and click the icon to move the objects to the Selected section. Note You cannot migrate data from the admin or local database. You can select databases, collections, or functions as the objects to be migrated. After an object is migrated to the destination instance, the name of the object remains unchanged. You can change the names of the objects that are migrated to the destination instance by using the object name mapping feature. For more information about how to use this feature, see Object name mapping.

8. In the lower-right corner of the page, click Precheck.
   Note

   • Before you can start the data migration task, a precheck is performed. You can start the data migration task only after the task passes the precheck.
   • If the task fails to pass the precheck, click the icon next to each failed item to view details. Troubleshoot the issues based on the causes and run the precheck again.
9. After the task passes the precheck, click Next.
10. In the Confirm Settings dialog box, specify the Channel Specification and select Data Transmission Service (Pay-As-You-Go) Service Terms.
11. Click Buy and Start to start the data migration task.
    

    Note We recommend that you do not manually stop a data migration task. Otherwise, data migrated to the destination instance will be incomplete. Wait until the data migration task automatically stops.
12. Switch your workloads to the destination ApsaraDB for MongoDB instance.

References

• Overview of replica set instance connections
• Overview of sharded cluster instance connections
• Configure sharding to maximize the performance of shards