This topic describes the features, usage calculation, billing method, performance impact, and data protection policies for Alibaba Cloud RDS for MySQL backups.
Backup features
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Category |
Feature |
Description |
Use case |
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Basic backup capabilities |
automatic backup |
A core automated protection mechanism. You can configure the backup cycle, time window, and retention period. |
For routine operations, the system automatically performs a full backup based on your policy. This backup, combined with log backups, enables point-in-time recovery (PITR). |
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manual backup |
Lets you create backups on demand. |
Create a traceable recovery point before major changes such as application upgrades or data migrations. |
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Advanced backup capabilities |
database/table-level backup |
Restore one or more specific databases or tables without restoring the entire instance. |
Ideal for fine-grained recovery scenarios, such as recovering from accidental table deletions or unintended data updates, to minimize business impact. |
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high-frequency backup (physical/snapshot) |
Enables you to quickly restore data to a specific point in time, significantly shortening the potential data loss window. |
Ideal for business scenarios with strict RPO (Recovery Point Objective) targets. |
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Disaster recovery and cost optimization |
cross-region backup |
Automatically backs up data to another region. |
Enable region-level disaster recovery to maximize availability. |
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infrequent-access backup |
Provides flexible backup policies to minimize the number of retained backup sets. |
Reduces backup storage costs while ensuring data availability. |
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Set backup retention policy after instance release |
Lets you retain backup data for a specified period after an instance is released (deleted). |
Prevents permanent data loss from accidental instance deletion, providing a final opportunity for recovery. |
Combining these features lets you build a comprehensive and highly configurable data protection system that meets your needs for routine operations, advanced disaster recovery, and performance and cost management.
Additionally, you can use the logical backup feature to implement automated backup for RDS for MySQL or self-managed MySQL. This feature supports cross-account backup, single database or table backup, remote backup, and storing backups in OSS.
Backup methods
Common data backup methods include logical backup, physical backup, and snapshot backup. The following table outlines the main differences among them.
|
Dimension |
Logical backup |
Physical backup |
Snapshot backup |
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Backup granularity |
Database object level (for example, tables, indexes, and stored procedures) |
Database file level (such as InnoDB data files) |
Cloud disk block level (the entire storage volume of an instance) |
|
Typical tools |
|
XtraBackup |
ESSD cloud disk snapshot service |
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Recovery precision |
Supports restoring a single database or table, but point-in-time recovery is not supported without binlogs. |
Supports point-in-time recovery (PITR) with second-level precision, using a full backup and log backups. |
Supports point-in-time recovery with log backups. |
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Use cases |
Migrating data across different versions, restoring a single table, and exporting data to a self-managed database. |
Fast full restore, disaster recovery, and cross-region backup. |
For scenarios requiring ultra-fast recovery (lowest RTO) and high business continuity. |
|
Related operations |
Backup usage
Backup components
RDS backups consist of data backups and log backups.
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Data backup: The system backs up your data and generates a backup set. This feature is enabled by default and cannot be disabled. Data backups are retained for at least 7 days and are performed at least twice a week. If you have minimal data backup needs, you can reduce your backup usage by decreasing the backup frequency and the retention period for backup sets.
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Log backup: Also known as an incremental backup. This feature is enabled by default but can be disabled. Log backups are retained for at least 7 days. Combining data backups with log backups enables point-in-time recovery (PITR), allowing you to restore data to any point in time within the retention period, starting from the time of the first full backup. If you have minimal log backup needs, you can reduce your backup usage by decreasing the backup set retention period or disabling log backups.
View backup usage
backup usage = data backup size + log backup size
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Go to the instance's Basic Information page and find the Backup Usage parameter in the Instance Resources section.
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After you upgrade the minor version of an RDS MySQL or RDS MySQL Serverless Basic Edition instance, the Backup Usage on the Basic Information page may display as 0. The value automatically returns to normal after the next scheduled backup is complete.
For example, the backup usage is 33.2 GB (data backup) + 20.19 MB (log backup). In this context, archive backup refers to data backups that have been retained for more than 2 years (730 days), and Data refers to non-archived data backups.
Backup usage
Backup pricing
Backup billable items
|
Billable item |
Billable item code |
Billed product |
Related documentation |
|
RDS basic backup |
BackupCharged |
ApsaraDB for RDS |
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Cross-region backup storage for instances with high-performance local disks |
DdrOssStorageSize |
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Cross-region backup storage for instances with cloud disks |
BackupStorageSize |
DBS |
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Cross-region backup network traffic |
NetworkOutDuplicationSize |
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Outbound traffic for backup downloads |
NetworkOutSize |
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Backup conversion for instances with cloud disks |
BackupAnalyticSize |
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Backup set retention for deleted instances with high-performance local disks |
StandardStorageSize |
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Backup set retention for deleted instances with cloud disks |
BackupStorageSize |
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Storage for database/table restore on instances with high-performance local disks |
CapacitySandboxStorageSize |
Free backup quota
The free backup quota depends on whether the storage compression feature is enabled.
|
Storage type |
Storage compression status |
Free quota |
Description |
|
high-performance cloud disk |
Disabled |
200% of the storage capacity |
View the Backup Usage (the actual logical data size) in the Usage Statistics section on the instance's Basic Information page. |
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Enabled |
400% of the storage capacity |
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high-performance local disk |
Disabled |
50% of the storage capacity |
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Enabled |
100% of the storage capacity |
The free backup quota applies only to regular backups, which are retained for up to 730 days. The quota does not cover archive backups, which are retained for more than 730 days.
Pricing
If your backup usage does not exceed the free quota, no fees are incurred for backups. Usage that exceeds the free quota is charged on a pay-as-you-go basis. The formula is: Hourly backup fee = (Backup usage - Free backup quota) × Backup unit price.
Usage notes
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Backup fees are based on your total backup usage, not the storage capacity of your ApsaraDB for RDS instance, because backups are stored separately.
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Therefore, when you analyze backup fees, check the backup usage instead of the storage capacity usage.
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Control-plane operations that involve cloud disk replacement (such as rebuilding a secondary instance) have the following impacts on cloud disk instances:
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The same-region backup storage for the cloud disk instance increases, resulting in higher same-region backup storage fees (Billable Item Code: BackupCharged).
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The cross-region backup network traffic for the cloud disk instance increases, resulting in higher cross-region backup network traffic fees (Billable Item Code: NetworkOutDuplicationSize).
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The cross-region backup storage for the cloud disk instance increases, resulting in higher cross-region backup storage fees (Billable Item Code: BackupStorageSize).
NoteFor example, if a DDL operation causes a long lag on the secondary instance, the system may automatically trigger a rebuild of the secondary instance, which increases costs.
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How to reduce backup fees
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Reduce backup usage
Delete or reduce backups. For more information, see Delete or reduce backups.
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Increase the free quota
Scale up storage capacity. For more information, see modify configurations.
The free quota is tied to the storage capacity. For example, for an instance with a high-performance local disk (which has a 50% free quota), increasing the storage capacity from 150 GB to 300 GB increases the free quota from 75 GB to 150 GB.
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Purchase an RDS Savings Plan or Storage Plan
If you need to retain backups for a long time and do not plan to scale up your storage capacity, purchase an RDS Savings Plan or Storage Plan to offset backup fees. A Storage Plan takes precedence over an RDS Savings Plan.
View backup bills
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On the Billing Details page, select Billable Item and Details. Enter the instance name, instance ID, or bill ID, and then click Search.
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Find the line items for the Instance Backup billable item.
Backup storage location
Data backups and log backups are stored in Alibaba Cloud backup storage and do not consume your instance's storage space.
We store backups in the same region as your RDS instance, but not always in the same availability zone. To create backups in a different region, use cross-region backup.
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Backup storage is not publicly accessible. To download a backup, see download backup.
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You are charged for any backup storage usage that exceeds the free quota. For more information, see backup fee.
Impact of backup
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Instance series |
Impact of backup |
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High Availability Series, Cluster Series, or Three-Node Enterprise Series |
Backups run on the standby instance, which does not affect the primary instance's CPU usage or performance. Note
In rare cases when the standby instance is unavailable, the backup runs on the primary instance. |
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Because this series uses a single-node architecture, backups affect the instance's performance. |
Backup data protection
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Tamper-proofing:
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RDS MySQL stores full physical backups and log backups in OSS, and full snapshot backups in the ESSD cloud disk snapshot service. Both storage methods provide WORM (Write-Once-Read-Many) immutability.
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Protection against malicious or accidental deletion:
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Manual deletion: You can delete manual backups, but not automatic backups. (For more information, see Delete or reduce backups.)
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Automatic expiration: Automatic backups are deleted after their retention period expires. However, you cannot disable this feature, which has a minimum 7-day retention period and runs at least twice a week. (For more information, see Automatic backup.) Therefore, the full and log data from your automatic backups can never be completely deleted.
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FAQ
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Q: My RDS instance's automatic backups are exceeding the free tier, and I'm being charged for them. How can I disable the backup feature?
A: The default RDS backup feature is enabled automatically and cannot be disabled. However, you can modify the automatic backup policy to delete existing backups or reduce the creation of new backups. For more information, see Delete or reduce backups.
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Q: My backup usage is within the free tier. Why am I still being charged?
A: You may have incurred these charges when your backup usage previously exceeded the free tier.
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Q: Can I use a storage package to offset charges for backup usage that exceeds the free tier?
A: You can use a storage package to offset charges for backup storage that exceeds the free tier for subscription or pay-as-you-go RDS instances. This does not apply to instances that use ESSD or SSD cloud disks.
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Q: Why is my backup size larger than my data size?
A: A cloud disk instance uses snapshot backups, which means the backup size can be much larger than the actual data size. The system calculates the size of a snapshot backup based on all non-empty blocks. Writing data to the disk in a fragmented way creates many non-empty blocks, which increases the size of the snapshot backup.
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Q: I reduced the backup retention period from x days to y days. Why hasn't the backup size changed?
A: If you had no backups older than y days to begin with, no backup data was deleted. Therefore, the total backup size will not decrease.
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Q: I've released my RDS for MySQL instance. Why am I still incurring backup charges?
A: Even after you release an RDS for MySQL instance, its backups remain on the Backups page in the RDS console if you configured a backup retention policy after instance release. According to the policy, backup storage is free for the first 7 days after you release the instance. After 7 days, billing for this storage begins.
Therefore, you are likely incurring charges because the retention period for your backups has exceeded the 7-day free period. Billing is based on the actual storage amount and the region. For detailed pricing, see pricing details. If you no longer need the backups, go to the Backup for Deleted Instances tab and change the retention policy for the target instance to None. This will prevent future backup storage charges.