This topic provides an overview of the backup feature supported by ApsaraDB RDS for MySQL. This feature allows you to restore historical data of an ApsaraDB RDS for MySQL instance with ease.
Backup introduction
You can back up your RDS instance by using one of the following methods:
ApsaraDB RDS: ApsaraDB RDS provides a default backup feature that supports full data backups and incremental log backups.
Database Backup (DBS): DBS provides the logical backup feature. The feature supports advanced capabilities such as cross-account backup, backup of individual databases or tables, cross-region backup, and storage of backup files in an Object Storage Service (OSS) bucket.
For more information about the differences between the default backup feature of ApsaraDB RDS and the logical backup feature of DBS, see Differences between default RDS backups and advanced DBS backups.
Composition
The system provides data backup and log backup.
Data backup: The system backs up data in your RDS instance and generates backup sets. You can restore data of the RDS instance to a specific point in time when a backup set is generated.
Log backup: The log backup feature is also known as the incremental backup feature. If you enable the log backup feature, your on-premises logs are uploaded. This way, log backups are generated. You can use the data backup feature and the log backup feature to restore data to a point in time that falls within the backup retention period.
For example, if an RDS instance has a data backup set that is created at a specified point in time and has log backups that are generated after the specified point in time, you can restore data for the RDS instance to any point in time after the specified point in time. The point in time is accurate to seconds.
Storage location
Data and log backup files of your RDS instance are stored by Alibaba Cloud and do not consume the storage capacity of your instance.
Data and log backup files of an RDS instance are stored in the same region, but not necessarily in the same zone as the RDS instance. For information about how to store the backup files in another region, see Use the cross-region backup feature.
The backup storage is inaccessible. For information about how to download backup files, see Download the backup files of an ApsaraDB RDS for MySQL instance.
Each RDS instance is allocated a free quota for backup storage. If your backup storage usage exceeds the free quota, you are charged additional fees. For more information, see Billable items and pricing for the backup storage of an ApsaraDB RDS for MySQL instance.
Impacts
RDS edition | Impact |
RDS High-availability Edition, RDS Cluster Edition, or RDS Enterprise Edition | Backup operations are performed on the secondary RDS instance. In this case, the operations do not occupy the CPU resources or affect the performance of the primary RDS instance. Note In rare cases when the secondary instance is unavailable, backups are performed on the primary instance. |
If an RDS instance runs RDS Basic Edition, the instance stands alone. All backup operations are performed on the RDS instance. In this case, the performance of the RDS instance decreases during a backup. |
Protection of backup files
Protection against tampering:
The full physical backup and log backup files of RDS for MySQL instances are stored in Object Storage Service (OSS). The full snapshot backup files are stored in ESSD snapshots. Both of the two storage media support the Write Once Read Many (WORM) technology, which means that the backup files are written to the storage only once and cannot be tampered with.
Protection against malicious or accidentally deletion:
Manual deletion: You can manually delete only backup files that are manually created but not backup files that are automatically created. For more information, see Delete backup files or reduce the size of backup files.
Automatic deletion of expired backup files: You can configure policies to automatically delete expired backup files that are automatically generated. However, you cannot disable automatic data backup for RDS for MySQL instances. Backup files are automatically generated at least twice a week and retained for at least seven days. Therefore, the backup files of full data and log data that are automatically generated cannot be completely deleted. For more information, see Configure automatic backup.