This topic provides answers to specific frequently asked questions about data migration and data synchronization.
- Q: What are data migration and data synchronization?
- Q: How do data migration and data synchronization work?
- Q: What is the difference between data migration and data synchronization by using DTS?
- Q: What do I do if an error occurs during a precheck?
Q: What are data migration and data synchronization?
- A: Data migration allows you to migrate data stored in key-value pairs from one Redis database to another. In most cases, the migration task stops after all data is migrated. The migration task is a one-time task.
- Data synchronization allows you to synchronize data stored in key-value pairs from one Redis database to another in real time. In most cases, the data synchronization task continuously runs to maintain data consistency between the source and destination databases.
Note Data migration and data synchronization replicate data from the source database to the destination database. The data of the source database remains unaffected.
Q: How do data migration and data synchronization work?
A: For more information, see System architecture and design concepts.
Q: What is the difference between data migration and data synchronization by using DTS?
| Comparison item | Data migration | Data synchronization |
|---|---|---|
| Scenario | The data migration feature is used to migrate data from on-premises databases, self-managed databases that are hosted on Elastic Compute Service (ECS) instances, and databases on third-party cloud platforms to Alibaba Cloud. | Data synchronization is used for real-time data synchronization between Redis databases. Data synchronization can be used in scenarios such as active geo-redundancy, disaster recovery, and data analytics. |
| Availability range | Support for data migration. | Support for data synchronization. |
| Feature | Supports data migration across self-managed databases that are deployed in virtual private clouds (VPCs) owned by different Alibaba Cloud accounts. |
|
| Billing method | Only the pay-as-you-go billing method is supported. | The pay-as-you-go and subscription billing methods are supported. |
| Billing rule | You are billed only when incremental data migration is in progress, including the period when incremental data migration is paused. You are not billed for schema migration and full data migration. |
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Note The data synchronization feature of Data Transmission Service (DTS) is suitable for more scenarios. We recommend that you use this feature to migrate data. For more information, see Overview.
Q: What do I do if an error occurs during a precheck?
A: Before you perform a data migration or data synchronization task, DTS runs a precheck on the source and destination databases to ensure that the task can run as expected. For information about how to troubleshoot errors that occur during prechecks, see Precheck and troubleshooting and Troubleshoot precheck failures.