In most cases, data files of ApsaraDB RDS for SQL Server instances are stored on Enterprise SSDs (ESSDs). Storage costs increase with data volume. To reduce costs and increase efficiency, ApsaraDB RDS for SQL Server provides a database-level data archiving feature. You can convert infrequently accessed online databases into cold storage databases on the Databases page of the ApsaraDB RDS console or by calling API operations. Cold data is stored in an OSS bucket at low costs. This helps separate hot data from cold data and reduce storage costs.
Prerequisites
The RDS instance meets the following requirements:
The RDS instance runs RDS Basic Edition.
Storage type: ESSD
Billing method: subscription or pay-as-you-go (Serverless not supported)
Region: Thailand (Bangkok), South Korea (Seoul), UK (London), SAU (Riyadh - Partner Region), and UAE (Dubai) are not supported.
Feature overview
ApsaraDB RDS for SQL Server works with OSS to manage data files and transfer them between cloud disks and OSS buckets based on the database detachment and attachment feature of native SQL Server. You can convert an online database into a cold storage database with a few clicks in the ApsaraDB RDS console. After conversion, data files are migrated from a cloud disk to an OSS bucket, significantly reducing storage costs. If you need to read data from or write data to a cold storage database, you can convert it back into an online database with a few clicks in the ApsaraDB RDS console. The entire process is simple and ensures data integrity.
Benefits
Cost savings: By converting infrequently accessed online databases into cold storage databases stored in low-cost OSS buckets, you can effectively reduce data storage costs and save a significant amount of money. For information about OSS cold storage pricing, see Billing.
Large capacity: By leveraging the massive storage architecture of OSS, you can achieve large-capacity archived data storage without being limited by the capacity of traditional storage media.
Low cost and high reliability: OSS features low cost and high reliability, which helps you archive data in a more cost-effective manner while maintaining data security and reliability.
No impact on business: The data archiving feature does not cause instance downtime or affect your normal business operations, ensuring business stability and continuity.
Considerations
Cold data archiving and restoration involve the transfer of database files between cloud disks and OSS buckets. If the database files are large, the transfer requires a long period of time to complete.
Limitations
Read and write restrictions on cold storage databases: After a database is converted into a cold storage database, you cannot directly access or perform read and write operations on the database. However, you can convert the cold storage database back to an online database as needed to meet read and write requirements.
Cross-edition upgrade restrictions: For Basic Edition instances with premium performance disks that have the data archiving feature enabled, you cannot upgrade the instances to instances of other editions.
Backup and recovery restrictions for cold storage databases: Backup and recovery are not supported for cold storage databases.
Data restoration restrictions: Only databases that exist in backup sets (not cold storage databases) can be restored. If a database is converted into a cold storage database, the restored instance does not include the cold storage database.
Handling of databases with the same name: If an instance has both an online database and a cold storage database with the same name, you cannot delete the database with that name. You can use the API operation (ModifyDatabaseConfig) to restore the cold storage database as an online database with a different name.
Limit on the number of cold storage databases: A single instance can have a maximum of 15 cold storage databases.
Billing
After you archive data to an OSS bucket, you are charged for OSS cold storage on a pay-as-you-go basis. The following table describes the unit prices.
Basic Edition
Region | Unit price |
China (Zhangjiakou), China (Hohhot), China (Ulanqab), China (Guangzhou), China (Hangzhou), China (Shenzhen), China (Chengdu), China (Qingdao), China (Shanghai), China (Beijing), and China (Heyuan) | USD 0.000032 per GB-hour |
China (Hong Kong), Singapore, Germany (Frankfurt), Japan (Tokyo), and Indonesia (Jakarta) | USD 0.000034 per GB-hour |
US (Virginia) | USD 0.000054 per GB-hour |
Malaysia (Kuala Lumpur) | USD 0.000057 per GB-hour |
US (Silicon Valley), Philippines (Manila) | USD 0.000058 per GB-hour |
Use data archiving
The data archiving feature is enabled by default. You do not need to manually enable it. You can directly convert online databases to cold storage databases and vice versa.
Step 1: Convert an online database to a cold storage database
Go to the Instances page. In the top navigation bar, select the region in which the RDS instance resides. Then, find the RDS instance and click the ID of the instance.
In the left-side navigation pane, click Databases.
In the Actions column of the target database, click More > Convert Online Database To Cold Storage Database.
Click OK and refresh the current page. The online database enters the conversion stage, and its status changes from Running to Converting to Cold Storage.
Step 2: Convert a cold storage database to an online database
Go to the Instances page. In the top navigation bar, select the region in which the RDS instance resides. Then, find the RDS instance and click the ID of the instance.
In the left-side navigation pane, click Databases.
In the Actions column of the target database, click More > Convert Cold Storage Database To Online Database.
Click OK and refresh the current page. The cold storage database enters the conversion stage.
References
You can also use the API operation (ModifyDatabaseConfig) to convert between online databases and cold storage databases.
For information about the storage types supported by ApsaraDB RDS for SQL Server, see Storage types.