This topic describes how to use Data Transmission Service (DTS) to migrate data between ApsaraDB for MongoDB instances that are created within different Alibaba Cloud accounts. DTS supports both full data migration and incremental data migration. You can use these two types of migration together to migrate data between ApsaraDB for MongoDB instances without downtime.

Prerequisites

Precautions

  • DTS consumes the resources of the source and destination instances during full data migration. This may increase the loads of the database servers. 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.
  • To ensure data consistency, we recommend that you do not write data to the source instance when full data migration of a standalone instance is in progress.
  • If the source and destination MongoDB databases use different versions or storage engines, make sure that your applications can run on both databases. For more information about the versions and storage engines that are 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.

Billing

Migration type Task configuration Internet traffic
Full data migration Free of charge. Charged only when data is migrated from Alibaba Cloud over the Internet. For more information, see Pricing.
Incremental data migration Charged. For more information, see Pricing.

Migration types

Migration type Description
Full data migration All existing data in the source instance is migrated to the destination instance.
Note Full data migration is supported for databases, collections, and indexes.
Incremental data migration Only the incremental data in the source instance is migrated to the destination instance.
Note
  • Incremental data migration can be used to synchronize the create and delete operations that are performed on databases, collections, and indexes.
  • Incremental data migration can be used to synchronize the create, delete, and update operations that are performed on documents.

Permissions required

Instance Full data migration Incremental data migration
Source instance Read permissions on the source database Read permissions on the source database, the database named admin, and the database named local
Destination instance Read and write permissions on the destination database Read and write permissions on the destination database
Note For more information about how to create and authorize accounts on an ApsaraDB for MongoDB instance, see Manage user permissions on MongoDB databases.

Preparations

  1. Log on to the ApsaraDB for MongoDB console by using the credentials of the Alibaba Cloud account within which the source instance is created.
  2. Apply for a public endpoint for the source instance. For more information, see Apply for a public endpoint.
  3. Add the CIDR block of the DTS server to an IP address whitelist of the source instance. For more information, see Configure a whitelist or an ECS security group for an ApsaraDB for MongoDB instance.
    Note The CIDR block of the DTS server varies based on the region where the destination instance resides. 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 resides in the China (Hangzhou) region and the destination instance resides in the China (Shenzhen) region, you need to add the CIDR block of the DTS server in the China (Shenzhen) region to an IP address whitelist of the source instance.

Procedure

  1. Log on to the ApsaraDB for MongoDB console.
  2. In the upper-left corner of the page, select the resource group and the region of the target instance.
  3. In the left-side navigation pane, click Replica Set Instances.
  4. Find the target instance and click its ID.
  5. In the upper-right corner of the page that appears, click Migrate Databases.
  6. On the Create Migration Task page, create a migration task.
    1. Specify the information about the source database and destination database.
      Configure the source and destination databases created within different Alibaba Cloud accounts
      Section Parameter Description
      N/A Task Name DTS automatically generates a task name. We recommend that you specify an informative name that helps identify the migration task. The task name does not need to be unique.
      Source Database Instance Type Select User-Created Database with Public IP Address.
      Instance Region Select the region where the source instance resides.
      Database Type Select MongoDB.
      Hostname or IP Address Enter the public endpoint that is used to connect to the source instance. Example: dds-bp1b47357f218e74****-pub.mongodb.rds.aliyuncs.com.
      Port Number Enter the port number that is used to connect to the source instance. For this example, enter 3717.
      Database Name Enter the name of the source database. The permissions on the source database must be granted to the account that is used to connect to the source instance.
      Note If you want to use the root account, enter admin in the Database Name field.
      Database Account Enter the username of the account that is used to connect to the source instance. For more information about the permissions that are required for the account, see Permissions required.
      Database Password Enter the password of the account that is used to connect to the source instance.
      Note After you specify the information about the source database, you can click Test Connectivity next to Database Password to check whether the information is correct. If the information is correct, the Passed message appears. If the information is incorrect, the Failed message appears and you must click Check next to the Failed message to modify the information.
      Encryption Specify whether to establish an encrypted connection. Valid values: Non-encrypted and SSL-encrypted. If you select SSL-encrypted, you must enable SSL encryption for the source instance before you create a migration task.
      Note
      • You can select SSL-encrypted only for ApsaraDB for MongoDB instances that run MongoDB Atlas.
      • If you select SSL-encrypted, more CPU resources are consumed.
      Destination Database Instance Type Select MongoDB Instance.
      Instance Region Select the region where the destination instance resides.
      MongoDB Instance ID Select the ID of the destination instance.
      Database Name Enter the name of the destination database. The permissions on the destination database must be granted to the account that is used to connect to the destination instance.
      Note If you want to use the root account, enter admin in the Database Name field.
      Database Account Enter the username of the account that is used to connect to the destination instance. For more information about the permissions that are required for the account, see Permissions required.
      Database Password Enter the password of the account that is used to connect to the destination instance.
      Note After you specify the information about the destination database, you can click Test Connectivity next to Database Password to check whether the information is correct. If the information is correct, the Passed message appears. If the information is incorrect, the Failed message appears and you must click Check next to the Failed message to modify the information.
    2. In the lower-right corner of the page, click Set Whitelist and Next.
      Note After the data of the source instance is migrated to the destination instance, you can delete the IP addresses that are no longer required from the IP address whitelists of the source instance and destination instance. For more information, see Configure a whitelist for an ApsaraDB for MongoDB instance.
    3. Specify the migration types and the objects that you want to migrate.
      Migration types and objects
      Action Description
      Specify the 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 that is updated during the migration process may not be migrated from the source instance to the destination instance.

      If you select only Incremental Data Migration, the following situations may occur:
      Specify the objects that you want to migrate
      1. Select one or more objects from the Available section.
      2. Click to move the selected objects to the Selected section.
      Note
      • Data in the database named admin and the database named local cannot be migrated.
      • The objects that you can migrate are databases, collections, and functions.
      • By default, after an object is migrated to the destination instance, the name of the object remains unchanged. If you want an object to have a different name after the migration, you can use the object name mapping feature of DTS to rename the object. For more information, see Object name mapping.
      Specify whether to rename objects You can use the object name mapping feature of DTS to rename the objects that you want to migrate. For more information, see Object name mapping.
      Specify the retry time for a failed connection to the source instance or destination instance By default, if DTS fails to connect to the source instance or destination instance, DTS retries to establish a connection within the next 12 hours. You can specify the retry time based on your business requirements. If DTS reconnects to the source instance and destination instance within the specified period of time, DTS resumes the migration task. If DTS cannot reconnect to the source instance or destination instance within the specified period of time, the migration task fails.
      Note When DTS retries to establish a connection, you are charged for the migration task. We recommend that you specify the retry time based on your business requirements. After the source instance and destination instance are released, we recommend that you release the migration task at your earliest opportunity.
    4. After you configure the preceding parameters, click Precheck in the lower-right corner of the page.
      Note
      • Before the migration task starts, you must perform a precheck. The migration task can be started only after it passes the precheck.
      • If the migration task fails the precheck, you can click the Info icon icon next to each failed item to view details about the failure.
        • You can troubleshoot the failures based on the information that is displayed. Then, you can perform a precheck again.
        • If you do not need to troubleshoot the failures, you can ignore the failed items and perform a precheck again.
    5. After the migration task passes the precheck, click Next.
    6. In the Confirm Settings dialog box, specify the Channel Specification parameter, and read and select Data Transmission Service (Pay-As-You-Go) Service Terms.
    7. Click Buy and Start to start the migration task.
  7. View the progress of the migration task.
    • Full data migration

      Do not manually stop a migration task. If you manually stop a migration task, the data that is migrated to the destination instance may be incomplete. You need only to wait until the migration task is completed and automatically stops.

    • Incremental data migration

      The migration task does not automatically stop. You must manually stop the migration task.

    1. Wait until Incremental Data Migration and The migration task is not delayed appear in the progress bar of the migration task. Then, stop data writes to the source database for a few minutes. The delay of Incremental Data Migration may be displayed in the progress bar.
    2. When the status of Incremental Data Migration changes to The migration task is not delayed, manually stop the migration task.
  8. Switch your workloads over to the destination instance.

What to do next

If you no longer need the source instance, release the source instance.

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

References

If the destination instance is a sharded cluster instance, you can configure data sharding for the destination instance based on your business requirements. For more information, see Configure sharding to maximize the performance of shards.