This topic describes how to migrate a standalone instance or a replica set instance to another region by using Data Transmission Service (DTS). You can perform full data migration and incremental data migration for a replica set instance. You can perform only full data migration for a standalone instance.
Prerequisites
The source instance is a standalone instance, replica set instance, or sharded cluster instance.
NoteDTS does not support incremental data migration from a standalone instance. For more information, see Migration types.
A public endpoint is applied for the source instance. For more information, see (Optional) Apply for a public endpoint for an ApsaraDB for MongoDB replica set instance.
The destination instance is created in the destination region. For more information, see Create an instance.
NoteWe recommend that you select a storage capacity of 10% larger than the storage capacity used by the source instance for the destination instance.
Background information
You may need to migrate an ApsaraDB for MongoDB instance to another region in the following scenarios:
Restructure your business.
Use an ApsaraDB for MongoDB instance to provide database services for applications deployed on an Elastic Compute Service (ECS) instance. However, the two instances are not in the same region.
In this example, an ApsaraDB for MongoDB instance in the China (Qingdao) region is migrated to the China (Hangzhou) region.
This example describes only how to migrate data from the source instance. After data is migrated, you can release the source instance if you no longer need the source instance.
Usage notes
DTS uses the resources of the source and destination databases during a full data migration. This may increase the loads on the database servers. If you migrate a large volume of data or the server specifications cannot meet your business requirements, database services may become unavailable. Before you migrate data, evaluate the impact of data migration on the performance of the source and destination instances. 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 the full data migration process.
If the source self-managed MongoDB database and the destination instance run different database versions or storage engines, make sure that no compatibility issues occur between them before you start migration. For more information about the database versions and storage engines supported by ApsaraDB for MongoDB, see MongoDB versions and storage engines.
By default, a new instance runs the latest minor version. This ensures high performance and stability.
The data is concurrently written to the destination instance. Therefore, the storage capacity occupied in the destination instance is 5% to 10% larger than the storage capacity occupied in the source instance.
Make sure that the destination instance does not have the same primary key as that in the source instance. The default primary key is _id. Otherwise, data may be lost. If the source and destination instances have the same primary key, delete the corresponding document in the destination instance without interrupting your business services.
Billing
Migration type | Task configuration fee | Internet traffic fee |
Full data migration | Free of charge. | Charged only when data is migrated from Alibaba Cloud over the Internet. For more information, see Billing overview. |
Incremental data migration | Charged. For more information, see Billing overview. |
Migration types
Migration type | Description |
Full data migration | DTS migrates the existing data of objects from the source MongoDB database to the destination MongoDB database. Note The following types of objects are supported: database, collection, and index. |
Incremental data migration | After full data migration is complete, DTS migrates incremental data from the source MongoDB database to the destination MongoDB database. Note
|
Permissions required for database accounts
Database | Full data migration | Incremental data migration |
Source instance | Read permissions on the source database | Read permissions on the source database, the admin database, and the local database |
Destination instance | Read and write permissions on the destination database | Read and write permissions on the destination database |
For more information about how to create and authorize a database account, see Manage the permissions of MongoDB database users.
Procedure
After data is migrated, switch your workloads 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 billed based on the pay-as-you-go billing method, you can release the instance. For more information, see Release an ApsaraDB for MongoDB instance.
If the source instance is billed based on the subscription billing method, you are not allowed to release the instance.