Migrate data between ApsaraDB for MongoDB instances created by different Alibaba Cloud accounts

Prerequisites

• The source instance is either a standalone instance or a replica set instance. If the source instance is a sharded cluster instance, we recommend that you use the built-in tools of MongoDB to migrate data. For more information, see Migrate a self-managed MongoDB database to ApsaraDB for MongoDB by using tools provided by MongoDB.
  Note You cannot use DTS to incrementally migrate the data of a standalone instance. For more information, see Migration types.
• The destination instance is created in the region. For more information, see Create a standalone instance, Create a replica set instance, or Create a sharded cluster instance.
  Note The storage capacity of the destination instance must be greater than the occupied storage space of 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. We recommend that you migrate data during off-peak hours.
• To ensure data consistency, we recommend that you do not write data to the source instance while full data migration of a standalone instance is in progress.
• If the source and destination instances run different database versions or storage engines, make sure that the instances do not have compatibility issues between them before you start the migration. For more information about the database versions and storage engines supported by ApsaraDB for MongoDB, see MongoDB versions and storage engines.
• To ensure better performance and stability of the instance, the system will upgrade the minor version to the latest version by default. If the minor version of your instance expires or is not included in the maintenance list and the instance is upgraded, migrated, changed, Created from a backup, Created by point-in-time, or performed Restore data to a new ApsaraDB for MongoDB instance.

Pricing

Migration types

Permissions required for database accounts

Preparations

1. Log on to the ApsaraDB for MongoDB console by using the Alibaba Cloud account to which the source instance belongs. For more information, see ApsaraDB for MongoDB console.
2. Apply for a public endpoint for the source instance. For more information, see Apply for a public endpoint for an ApsaraDB for MongoDB instance.
3. Add the Classless Inter-Domain Routing (CIDR) blocks of DTS servers to a whitelist of the source instance. For more information, see Configure a whitelist or an ECS security group for an ApsaraDB for MongoDB instance.
   Note You can determine the CIDR blocks you need to add based on the region where the destination instance is deployed. For more information, see Add the CIDR blocks of DTS servers to the security settings of on-premises databases.

   For example, if the source instance is in China (Hangzhou) and the destination instance is in China (Shenzhen), add the CIDR blocks of the DTS servers in China (Shenzhen) to a whitelist of the source instance.

Procedure

1. Log on to the Data Transmission Service console with the Alibaba Cloud account to which the destination ApsaraDB for MongoDB instance belongs.
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 is deployed.
   
4. In the upper-right corner of the page, click Create Migration Task.
5. Create a data migration task.
   1. Configure the source and destination databases for the data migration task.

      Section	Parameter	Description
      N/A	Task Name	The name of the migration task. DTS automatically generates a task name. We recommend that you set a descriptive name that makes it easy to identify. Task names do not have to be unique.
      Source Database	Instance Type	Select User-Created Database with Public IP Address.
      	Instance Region	The region where the source instance is deployed.
      	Database Type	The database engine of the source instance. In this example, select MongoDB.
      	Hostname or IP Address	Enter the domain name obtained from the public endpoint of the source instance. For example, enter dds-1udxxxxxxx-pub.mongodb.rds.aliyuncs.com.
      	Port Number	Enter 3717, which is the service port of the source instance.
      	Database Name	The name of the database corresponding to the username if authentication is enabled. Note If the database account is root, enter admin.
      	Database Account	The account that is used to log on to the source database. For more information about the permissions that are required for the account, see Permissions required for database accounts.
      	Database Password	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 information is valid. If the information is valid, the Passed message appears. If the Failed message appears, click Check in the Failed message to modify the information.
      	Encryption	Indicates whether an encrypted connection is used for the source instance. Select Non-encrypted or SSL-encrypted. If you select SSL-encrypted, you must enable SSL encryption for the source instance before you configure the data synchronization task. Note You can select SSL-encrypted only for source MongoDB Atlas databases. If you select SSL-encrypted, more CPU resources will be consumed.
      Destination Database	Instance Type	The category of the destination instance. In this example, select MongoDB Instance.
      	Instance Region	Select the region where the destination ApsaraDB for MongoDB instance is deployed.
      	MongoDB Instance ID	The ID of the destination instance. In this example, select the ID of the destination ApsaraDB for MongoDB instance.
      	Database Name	The name of the database corresponding to the username if authentication is enabled. Note If the database account is root, enter admin.
      	Database Account	The account that is used to log on to the destination database. In this example, enter the destination ApsaraDB for MongoDB database account. For more information about the permissions that are required for the account, see Permissions required for database accounts.
      	Database Password	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 information is valid. If the information is valid, the Passed message appears. If the information is invalid, the Failed message appears, and you must click Check next to the Failed message to modify the information.

   2. In the lower-right corner, click Set Whitelist and Next. In the dialog box that appears, click Next.
      Note After the migration is complete, you can remove the IP addresses from the whitelist if they are no longer needed. For more information, see Configure a whitelist.
   3. Select the migration types and the objects to be migrated.

      Parameter	Description
      Migration Types	We recommend that you select both Full Data Migration and Incremental Data Migration to ensure the consistency of migrated data. If you select only Full Data Migration, the data updated during the migration process may not be migrated from the source instance to the destination instance. If you select only Incremental Data Migration, Only incremental data generated in the source instance is migrated. In incremental migration mode, triggers cannot be synchronized. For more information, see Configure a data synchronization task for a source database that contains a trigger.
      Objects	In the Available section, select the objects you want to migrate and then click the icon to move them to the Selected section. Note Data in the admin and local databases cannot be migrated. A migration object can be a database, collection, or function. By default, the name of an object remains unchanged after migration. If you want a different object name after migration, use the object name mapping feature provided by DTS. For more information, see Object name mapping.
      Specify whether to rename object names	You can use the object name mapping feature to change the names of the objects that are synchronized to the destination instance. For more information, see Object name mapping.
      Specify the retry time for failed connection to the source or destination database	By default, if DTS fails to connect to the source or destination database, DTS retries within the next 12 hours. You can specify the retry time based on your needs. If DTS reconnects to the source and destination databases within the specified time, DTS resumes the data migration task. Otherwise, the data migration task fails. Note When DTS retries a connection, you are charged for the DTS instance. We recommend that you specify the retry time based on your business needs. You can also release the DTS instance at your earliest opportunity after the source and destination instances are released.

   4. After the preceding configurations are complete, you can select one of the following operations based on your requirements:
      • If you do not need to perform the data migration task immediately, click Save in the lower-right corner of the page.

        To start a data migration task later, find the migration task in the data migration task list, click Start Task, and then click OK in the message that appears.

      • To perform the data migration task immediately, click Precheck in the lower-right corner of the page.
      Note

      • A precheck is performed before the migration task starts. You can start the data migration task only after the task passes the precheck.
      • If the task fails to pass the precheck, you can click the icon next to each failed item to view details.
        • You can troubleshoot the issues based on the causes and run a precheck again.
        • If you do not need to troubleshoot the issues, you can ignore failed items and run a precheck again.
   5. After the task passes the precheck, click Next.
   6. In the Confirm Settings dialog box, specify the Channel Specification and select Data Transmission Service (Pay-As-You-Go) Service Terms.
   7. Click Buy and Start to start the migration task.
      • Full data migration

        Do not manually stop a task during full data migration. Otherwise, the system may fail to perform a full data migration. Wait until the full data migration task automatically stops.

      • Incremental data migration
        An incremental data migration task does not automatically end. You must manually end the task. Perform the following operations:

        Note Select an appropriate time to manually stop the migration task. For example, you can stop the migration task during off-peak hours or before you switch your workloads to the destination ApsaraDB for MongoDB instance.

        1. Wait until Incremental Data Migration and The migration task is not delayed appear in the progress bar of the migration task. Then, stop writing data to the source database for a few minutes. The delay time of Incremental Data Migration may appear in the progress bar.
        2. After the status of incremental data migration changes to The migration task is not delayed, manually stop the migration task.
   8. Switch your workloads to the destination ApsaraDB for MongoDB instance.

What to do next

Determine whether to release the source instance.

• If the source instance uses the pay-as-you-go billing method, release the source instance. For more information, see Release an ApsaraDB for MongoDB instance.
• If the source instance uses the subscription billing method, you cannot release the source instance.

References

If you migrate data to a sharded cluster instance, you can configure data sharding as needed. For more information, see Configure sharding to maximize the performance of shards.