Upgrade a one-way sync instance to a two-way sync instance - Data Transmission Service

This topic describes how to upgrade the synchronization topology of a sync task from one-way to two-way to meet evolving business needs. This upgrade lets you configure a reverse sync task for more efficient and comprehensive data exchange.

Applicability

A source instance must meet the following conditions to be converted into a bidirectional sync task.

The task is a one-way sync task. This means that Synchronization Topology is set to One-way Synchronization.
The database types and versions of the source and destination databases support two-way synchronization. For example, both the source and destination databases are MySQL 8.0.
For more information, see Supported databases and Overview of data synchronization solutions.
The Status of the task is Running.
The account for the destination database has the required permissions.
For more information, see Permissions of the destination database account.
An SSL Connection must not be configured for the source or destination database instance. You cannot upgrade the task to a bidirectional sync task if an SSL Connection is enabled.

Supported instances

Source database	Destination database
MySQL	MySQL and PolarDB for MySQL
PolarDB for MySQL	MySQL and PolarDB for MySQL
PostgreSQL	PostgreSQL and PolarDB for PostgreSQL
PolarDB for PostgreSQL	PolarDB for PostgreSQL
PolarDB (Compatible with Oracle)	PolarDB (Compatible with Oracle)

Permissions of the destination database account

Destination database type	Required permissions	Account creation and authorization
MySQL	RDS for MySQL instance Privileged account. Self-managed MySQL database The SELECT, REPLICATION CLIENT, REPLICATION SLAVE, and SHOW VIEW permissions, and the permissions to create databases and tables.	Create an account Create an account for a self-managed MySQL database and configure binary logging
PolarDB for MySQL	Privileged account.	Create and manage a database account
PostgreSQL	RDS for PostgreSQL instance A privileged account that is the owner of the database. Self-managed PostgreSQL database Superuser permissions.	Create an account and Create a database. CREATE USER and GRANT.
PolarDB for PostgreSQL	A privileged account that is the owner of the database.	Create a database account and Database management.
PolarDB (Compatible with Oracle)	A privileged account that is the owner of the database.	Create a database account and Database management.

Billing

If the billing method is subscription:
Upgrade fee = (Daily price of the task after the upgrade - Daily price of the task before the upgrade) × Remaining days from the upgrade date to the expiration date.
Note
The daily price of the upgraded task depends on the number of remaining days until the expiration date.
- If the number of remaining days is less than 300, the monthly subscription price is used.
- If the number of remaining days is 300 or more, the annual subscription price is used.
If the billing method is pay-as-you-go:
You are charged based on the specifications of the upgraded task. The billing rule remains the same, and you are charged on an hourly basis.

Note

For more information about pricing, see Billing overview.

Usage notes

You can only upgrade a sync task from one-way to two-way. You cannot downgrade a sync task from two-way to one-way.
One-way synchronization between PolarDB-X 2.0 database instances cannot be upgraded to two-way synchronization.

Procedure

Use one of the following methods to go to the Data Synchronization page and select the region in which the data synchronization instance resides.
DTS console
1. Log on to the DTS console.
2. In the left-side navigation pane, click Data Synchronization.
3. In the upper-left corner of the page, select the region in which the data synchronization task resides.
DMS console
Note
The actual operations may vary based on the mode and layout of the DMS console. For more information, see Simple mode and Customize the layout and style of the DMS console.
1. Log on to the DMS console.
2. In the top navigation bar, move the pointer over Data + AI and choose DTS (DTS) > Data Synchronization.
3. From the drop-down list to the right of Data Synchronization Tasks, select the region in which the data synchronization instance resides.
Find the target task.
In the Actions column of the target task, choose > Change To Two-way Sync.
In the dialog box that appears, click OK to complete the upgrade.
After the upgrade is complete, a reverse sync task in the Not Configured state appears below the original sync task.
Configure the reverse sync task as needed.