Download the backup files of an ApsaraDB RDS for PostgreSQL instance - ApsaraDB RDS

This topic describes how to download the backup files of an ApsaraDB RDS for PostgreSQL instance.

Billing rules

If your RDS instance use local disks and you download the backup files of the RDS instance, you are charged fees for Internet traffic generated for the download. If your RDS instance use cloud disks and you download the backup files of the RDS instance, you are charged fees for file conversion and Internet traffic generated for the download.

Traffic fees

Downloads over an internal network: You are not charged for the traffic that you consume.
Downloads over the Internet: After the free quota is exhausted, you are charged for the excess traffic that you consume based on the pay-as-you-go billing method. Fees are deducted from your account on a daily basis. For more information, see Billing overview.
Free quota for backup downloads over the Internet: The free quota for each RDS instance is 500 GB per month.

Note

If the backup files fail to be downloaded, no backup file conversion fees or traffic fees are generated.
To view the volume of traffic that you consumed to download backup files over the Internet, you can log on to the ApsaraDB RDS console, find your RDS instance, go to the Basic Information page, and then view the Backup Downloads parameter in the Usage Statistics section of the page.

Backup file conversion fees

If your RDS instance use cloud disks and you use the advanced download feature to download the backup files of the RDS instance, the snapshot backup files are converted into CSV, SQL, or Parquet files. Starting October 18, 2022, if you use the advanced download feature to download backup files, you are charged a backup file conversion fee based on the pay-as-you-go billing method. For more information, see [Notice] Generation of fees for the backup download feature starting October 18, 2022. The following table describes the unit price for backup file conversion.

Region	Unit price (USD/GB)
Public Cloud	0.03125

Download methods

RDS instances that use cloud disks

You can create an advanced download task by point in time or backup set based on the RDS edition or instance type of your RDS instance. You can set the Download Destination parameter to URL or directly upload the downloaded data to your Object Storage Service (OSS) bucket to facilitate data analysis and offline archiving.

Prerequisites

Your RDS instance meets the following requirements:
- The RDS instance runs PostgreSQL 10, PostgreSQL 11, PostgreSQL 12, PostgreSQL 13, PostgreSQL 14, or PostgreSQL 15.
- The RDS instance uses the enhanced SSD (ESSD) storage type.
Note
- You can go to the Basic Information page of the RDS instance to view the preceding information.
- If your RDS instance uses the local SSD or standard SSD storage type and you want to use this feature, you can upgrade the major engine version of the RDS instance to upgrade the storage type to ESSD. For more information, see Upgrade the major engine version of an ApsaraDB RDS for PostgreSQL instance.
Your RDS instance resides in one of the following regions: China (Chengdu), China (Guangzhou), China (Qingdao), China (Beijing), China (Shanghai), China (Zhangjiakou), China (Hangzhou), China (Shenzhen), China (Hong Kong), Malaysia (Kuala Lumpur), Indonesia (Jakarta), Japan (Tokyo), Singapore, US (Silicon Valley), and US (Virginia).
Note
The feature will be available in other regions soon.
You must go to the Cloud Resource Access Authorization page to authorize Database Backup (DBS) to access resources in your Alibaba Cloud account.

Feature matrix

RDS edition	Instance type	Database engine	Download by backup set	Download by point in time
RDS High-availability Edition	Dedicated instance family	PostgreSQL 10 with the ESSD storage type PostgreSQL 11 with the ESSD storage type PostgreSQL 12 with the ESSD storage type PostgreSQL 13 with the ESSD storage type PostgreSQL 14 with the ESSD storage type PostgreSQL 15 with the ESSD storage type	Supported	Not supported
RDS High-availability Edition	General-purpose instance family		Supported	Supported
RDS Basic Edition	New general-purpose instance family		Supported	Not supported
RDS Basic Edition	General-purpose instance family		Supported	Not supported

Limits

The following objects in schemas are involved:
- Supported: tables, indexes, user-defined data types, unique constraints, foreign key constraints, NOT NULL constraints, and table inheritance
- Not supported: CHECK constraints
The following data types are supported:
Numeric, string, datetime, Boolean type, enumerated type, array, UUID, jsonb, and bytea
Note
Parquet files must be converted to strings.
The following types of primary keys are supported:
SMALLINT, Integer, BigInt, SMALLSERIAL, SERIAL, BIGSERIAL, CHAR, VARCHAR, and composite primary key. In addition, tables that do not have primary keys are also supported.
The following system databases cannot be exported:
template1, template0, and rdsadmin
The following system tables cannot be exported:
information_schema and pg_catalog
If you set the Download Destination parameter to OSS, only the Standard storage class is supported. For more information about how to change the storage class, see Convert storage classes.

Procedure

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 Backup and Restoration.
On the Data Backup tab of the page that appears, find the backup file that you want to download and click Download Instance Backup in the Actions column.
Note
By default, the ApsaraDB RDS console displays the backup files that were generated over the most recent eight days. If you want to view the backup files that were generated eight days ago, you must change the time range.
In the Select Download Mode step of the wizard, select Download by Time or Download by Backup Set and click Next.
Note
The Download by Time option is available only when the log backup feature is enabled for your RDS instance. For more information about how to enable the log backup feature, see Enable or disable the log backup feature.
In the Select Download Content step of the wizard, click Next.
Note
Download Instances is selected by default.
In the Select Download Destination and Format step of the wizard, configure the following parameters and click Complete.
Note
We recommend that you set the Download Destination parameter to OSS. This method is efficient.
- Set the Download Destination parameter to URL.
  Configure the Download Format parameter. Then, read and select the required content.
- Select the Download Destination parameter to OSS.
  1. Configure the Bucket Name and Directory Prefix parameters.
  2. Configure the Download Format parameter.
  3. Read and select the required content.
Note
- You can set the Download Format parameter to CSV, SQL, or Parquet.
- If you do not have the permissions to access OSS resources, follow the instructions in the console and click Authorize and then > Confirm Authorization Policy. After the permissions are granted, configure the parameters for the advanced download task.
Go to the Backup Download tab.
- If you set the Download Destination parameter to URL, perform the following steps after the Status parameter of the advanced download task changes to Finished:
  1. Click Generate Link in the Download Destination column.
  2. In the Generate Link dialog box, configure the Validity Period parameter and click Generate Link. Then, you can download backup data by using the generated URL.
    Note
    If you set the Download Destination parameter to URL, the downloaded data is temporarily stored in the built-in storage of DBS. For more information, see Built-in storage and OSS.
    The validity period of the URL ranges from 5 minutes to 1 day. The default validity period is 2 hours.
    You can obtain the download URL within three days after the download task is complete. After the URL expires, the downloaded data is deleted. If you want to use the data, you must initiate a new download task and obtain the new download URL.
    A download URL is generated based on the validity period that you specify. We recommend that you save the URL at the earliest opportunity and keep the URL confidential.
    If you use a third-party download tool to download the backup file, additional download traffic may be generated. As a result, you may be charged additional fees. Proceed with caution.
    For more information about how to download a backup file, see Appendix: Download commands.
    When you perform an advanced download, backup file conversion fees and traffic fees are generated. For more information, see Billing rules.
    You can use CSV files or SQL files that are downloaded and converted by using the advanced download feature to restore the data of your RDS instance to a self-managed PostgreSQL instance. For more information, see Restore the data of an ApsaraDB RDS for PostgreSQL instance to a self-managed PostgreSQL instance by using a CSV file or an SQL file.
- If you set the Download Destination parameter to OSS and the status of the task changes from Running to Finished, the download is successful. You can view and use the downloaded file in the specified OSS bucket.
  Note
  If you use this method, data is directly downloaded to your OSS bucket, and you can use and delete the data based on your business requirements.

RDS instances that use local disks

Prerequisites

The RDS instance uses local disks.
Note
You can go to the Basic Information page of the RDS instance to view the preceding information.
The RAM user that you want to use to log on to your RDS instance has permissions to download backup files. For more information about how to grant permissions to a RAM user, see Grant backup file download permissions to a RAM user with read-only permissions.

Procedure

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 Backup and Restoration.
Click the Data Backup or Log Backup tab.
- If you want to download a data backup file, click the Data Backup tab.
- If you want to download a log backup file, click the Archived Logs tab.
Select a time range. This step is required if you want to view the backup files that are generated eight days ago. The default time range spans the most recent eight days.
Find the backup file that you want to download and click Download Instance Backup in the Actions column.
Note
- If Download Instance Backup is not displayed, check whether all prerequisites are met.
- If you want to download a data backup file and use the file to restore data, we recommend that you select the data backup file that is created at the point in time closest to the point in time at which the required data exists.
- If you want to download an archived log backup file and use the file to restore data to an on-premises database, take note of the following items:
  - The instance No. of the archived log backup file must be the same as that of the data backup file that is used with the archived log backup file.
  - The start time of the log backup file must be later than the end time of the data backup file and earlier than the specified point in time.
In the dialog box that appears, click Download or copy the URL that you can use to download the backup file.
- Copy Internal URL: If your virtual private cloud (VPC)-type Elastic Compute Service (ECS) instance can communicate with the RDS instance over an internal network, you can log on to your ECS instance and use the internal URL to download the log backup file. This method is faster and more secure.
- Copy Public URL: If the RDS instance cannot be connected over an internal network, you can use the public URL to download the log backup file.
Note
- The download URLs are valid only for one hour. If the download URLs expire, you can refresh the page to obtain the latest download URLs.
- If you use the internal URL to download the log backup file, make sure that the server to which you log on and the RDS instance reside in the same VPC. If the server and the RDS instance reside in VPCs of different regions or if the server resides in the classic network while the RDS instance resides in a VPC, you cannot download the log backup file by using the internal URL on the server.
- I have learnt the billing rules for backup file download. is selected by default. If you use the external URL to download the backup file, you are charged for the excess Internet traffic that you consume. For more information,see Billing rules.

Appendix: Download commands

This section describes the commands that are commonly used to download backup files.

Note

If the speed of a download is lower than 64 KB per second, the download may be interrupted. When you download a backup file, we recommend that you ensure optimal network status.
If you want to download a backup file to a disk that is attached by using ossfs, you must adjust the value of the multipart_size parameter for ossfs. The maximum value of this parameter is 100 GB. If the size of the backup file that you want to download exceeds 100 GB, the download fails. For more information about ossfs and its parameter settings, see Overview and Common options.
We recommend that you use the commands, such as wget and curl, that are provided in this topic to download a backup file. If you use a third-party tool to download a backup file, the backup file may be downloaded multiple times. As a result, the amount of data that is downloaded is greater than the size of the backup file, and you may be charged for the traffic that is consumed to download the excess amount of data over the Internet.

wget

Command: nohup wget -c -t 0 "The URL that is used to download the backup file" -O The save path and name of the backup file that you want to download > The file to which the downloaded data is saved &
Example: nohup wget -c -t 0 "https://example.aliyundoc.com/examplebackup.qp.xb" -O /backup/examplebackup.qp.xb > /tmp/download.log &
The following information provides the meanings of the options in the preceding command:
-t 0: enables an unlimited number of retries. 
-c: enables resumable uploads. 
-O: specifies the save path and name of the backup file that you want to download. 
nohup: prevents interruptions to the download and specifies that the process automatically exits after the download is complete. If you accidentally replicate data or disconnect your database client during the download, the download is interrupted.

curl

Command: nohup curl -C --- retry 10 "The URL that is used to download the backup file" -o The user-defined name of the downloaded backup file> The file to which the downloaded data is saved&
Example: nohup curl -C --retry 10 "https://example.aliyundoc.com/examplebackup.qp.xb" -o backup.qp.xb > /tmp/download.log &
The following information provides the meanings of the options in the preceding command:
--retry 10: enables up to 10 retries if the download fails. 
-C -: enables resumable uploads. 
-o: specifies the save path and name of the backup file that you want to download. 
nohup: prevents interruptions to the download and specifies that the process automatically exits after the download is complete. If you accidentally replicate data or disconnect your database client during the download, the download is interrupted.

Related operations

Operation	Description
DescribeBackups	Queries the data backup files of an instance.
DescribeDownloadSupport	Checks whether an instance supports advanced downloads.
CreateDownload	Creates an advanced download task.
DescribeDownloadTask	Queries download tasks.
DescribeDownloadBackupSetStorageInfo	Queries the storage information about the downloaded backup files.