Migrate data from a standalone instance to a replica set or sharded cluster instance - User Guide| Alibaba Cloud Documentation Center

ApsaraDB for MongoDB provides standalone instances, replica set instances, and sharded cluster instances. Standalone instances are designed to store non-core enterprise data, such as data in development and testing scenarios. Replica set instances and sharded cluster instances are more suitable for production scenarios. This topic describes how to migrate data from a standalone instance to a replica set or sharded cluster instance by using Data Transmission Service (DTS).

Prerequisites

The available storage space of the destination instance is larger than the total size of the data in the source instance.

Precautions

DTS uses resources of the source and destination instances during full data migration. This may increase the load of the database server. If the data volume is large or the specification is low, the database server 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 database engine versions or storage engines, make sure that the versions or storage engines are compatible. For more information, see MongoDB versions and storage engines.

Billing for data migration


Migration type	Instance configuration fee	Internet traffic fee
Support for full data migration	Free of charge	Free of charge

Migration types

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

Note The following types of objects are supported: database, collection, and index.

Required database account permissions


Instance	Permissions
Source ApsaraDB for MongoDB instance	Read permissions on the source database
Destination ApsaraDB for MongoDB instance	Read/write permissions on the destination databases

For more information about how to create and authorize a database account, see Manage MongoDB databases by using DMS.

Procedure

Log on to the DTS console.
In the left-side navigation pane, click Data Migration.
At the top of the Migration Tasks page, select the region where the destination ApsaraDB for MongoDB instance resides.
In the upper-right corner of the page, click Create Migration Task.

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 is deployed.
	MongoDB Instance ID	Select the ID of the source ApsaraDB for MongoDB instance.
	Database Name	Enter the name of the authentication database to which the database account belongs. Note If you want to use the root account, specify admin for the Database Name parameter.
	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 Required database account permissions.
	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	The type of the instance. In this example, select MongoDB Instance.
	Instance Region	The region where the ApsaraDB for MongoDB instance is deployed.
	MongoDB Instance ID	Select the ID of the ApsaraDB for MongoDB database.
	Database Name	Enter the name of the authentication database to which the database account belongs. Note If you want to use the root account, specify admin for the Database Name parameter.
	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 Required database account permissions.
	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.

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.

Select the migration types and the objects to be migrated.

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 Data in the admin and local databases cannot be migrated. You can select databases, collections, or functions to migrate. By default, the name of an object remains unchanged after the migration. You can change the names of the objects that are migrated to the destination database by using the object name mapping feature. For more information about how to use this feature, see Object name mapping.

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.
After the task passes the precheck, click Next.
In the Confirm Settings dialog box, specify the Channel Specification and select Data Transmission Service (Pay-As-You-Go) Service Terms.
Click Buy and Start to start the data migration task.

Note Do not manually stop a task during full data migration. Otherwise, data migrated to the destination database will be incomplete. Wait until the data migration task automatically stops.
Switch your workloads to the destination ApsaraDB for MongoDB instance.