PolarDB:Create and manage a global database network

Scope

Pricing

When you use a GDN, you are charged for the clusters and any inter-region data transfer fees. Data transfer fees vary based on whether the transfer is cross-border.

• Non-cross-border data transfer (Free)

  • Scenario: The primary and secondary clusters are both deployed in regions outside the Chinese mainland, or both are deployed in regions within the Chinese mainland.

  • Billing rule: Free.

• Cross-border data transfer (Billable)

  Important

  Cross-border data transfer fees will be charged starting from 00:00 on January 1, 2026 (Singapore time). Before this date, this service is free.

  • Scenario: One of your clusters (primary or secondary) is deployed in a region outside the Chinese mainland, and the other is deployed in a region in the Chinese mainland.

  • Billing rule: USD 0.80 per GB, billed hourly. The fee is calculated based on the amount of Redo Log data that is physically replicated from the primary cluster to a cross-border secondary cluster within one hour. You can estimate this traffic fee by querying the physical position converted from the log sequence number (LSN).

    Click to view a billing example

    Example

    For example, at 09:00, you query the physical write position of the log and it is ib_logfile1/648143676. At 10:00, the position is updated to ib_logfile3/648142342. This indicates that the amount of data written in this hour is the difference between the two positions.

    1. Amount written to the start file (ib_logfile1):
       Subtract the start offset from the total file size. Each log file is 1 GB (1,073,741,824 bytes). The amount written is 1073741824 - 648143676 = 425598148 bytes.

    2. Amount written to the intermediate file (ib_logfile2):
       After ib_logfile1 is full, the system completely writes ib_logfile2. This amount is 1,073,741,824 bytes (1 GB).

    3. Amount written to the end file (ib_logfile3):
       This is the offset at the end, which is 648142342 bytes.

    Therefore, the total amount written = 425598148 + 1073741824 + 648142342 = 2147482314 bytes. This is 2147482314 / 1024 / 1024 / 1024 = 1.999998 GB (rounded down to six decimal places). The cross-border data transfer fee for this hour is approximately 1.999998 GB × USD 0.80/GB = USD 1.5999984.

    Query the log write progress and physical file offset

    -- Query the current write progress of the log system.
    SHOW STATUS LIKE 'Innodb_log_write_lsn'; 
    +----------------------+------------+
    | Variable_name        | Value      |
    +----------------------+------------+
    | Innodb_log_write_lsn | 1721889596 |
    +----------------------+------------+
    
    -- Query the physical file offset in bytes.
    SELECT lsn_to_pos(1721889596); 
    +------------------------+
    | lsn_to_pos(1721889596) |
    +------------------------+
    | ib_logfile1/648143676  |
    +------------------------+

Create a global database network

1. Log on to the PolarDB console. In the navigation pane on the left, click Global Database Network.

2. On the GDN page, click Create GDN.

3. In the Create GDN dialog box, configure the following parameters.

   Configuration	Description
   Compatibility	Select MySQL.
   Version	Fixed at Active-passive.
   Name	The name of the GDN. Enter a descriptive name for easy identification. The name does not need to be unique.
   Primary Region	Select the region where the primary cluster is located. Note First, decide which cluster to use as the primary one, then select the region where that cluster is located.
   Primary Cluster	Select an existing cluster as the primary cluster of the GDN.
   Global Domain Name	Specifies whether to enable the global domain name feature. A global domain name provides a unified endpoint for the GDN. It not only enables nearest access but also ensures the domain name remains unchanged after a primary cluster switchover.

4. Click OK. You can view the created GDN on the GDN page. You can then add a secondary cluster to the GDN.

View information about a global database network

Log on to the PolarDB console, click the GDN ID on the GDN page, and view its basic information, cluster list, and topology graph on the details page.

Delete a GDN

1. Log on to the PolarDB console. In the navigation pane on the left, click Global Database Network.

2. On the GDN page, find the target GDN and click Delete in the Actions column.

   Note

   If the Delete button is grayed out, this means the GDN still contains secondary clusters. You must delete the secondary clusters before you can delete the GDN.

3. Read the notes in the dialog box that appears. After you confirm the information, click OK to delete the GDN.

References

• Add and manage a secondary cluster

• Connect to a GDN: Describes how to connect to a GDN.

• Create a global domain name: Describes how to create a unified endpoint that enables nearest access and remains unchanged after a primary cluster switchover.

Related API operations

FAQ