If your business requires bidirectional data exchange — such as active-active disaster recovery or multi-region writes — you can upgrade an existing one-way sync task to two-way synchronization. After the upgrade, DTS automatically creates a reverse sync task, so you can configure both directions without starting over.
Prerequisites
Before you begin, make sure that:
The task is a one-way sync task — Synchronization Topology is set to One-way Synchronization
The task Status is Running
The source and destination database types and versions support two-way synchronization (for example, both are MySQL 8.0). For supported combinations, see Supported instances and Data synchronization scenarios
The destination database account has the required permissions. For details, see Required permissions
Neither the source nor the destination database has an SSL Connection configured — SSL connections block the upgrade
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) |
Required permissions
The destination database account must have the following permissions before you start the upgrade.
| Destination database | Required permissions | How to create and authorize |
|---|---|---|
| MySQL (RDS instance) | Privileged account | Create an account |
| MySQL (self-managed) | SELECT, REPLICATION CLIENT, REPLICATION SLAVE, and SHOW VIEW, plus permissions to create databases and tables | 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 instance) | Privileged account that is the owner of the database | Create an account and Create a database |
| PostgreSQL (self-managed) | Superuser permissions | CREATE USER and GRANT |
| PolarDB for PostgreSQL | Privileged account that is the owner of the database | Create a database account and Database management |
| PolarDB (Compatible with Oracle) | Privileged account that is the owner of the database | Create a database account and Database management |
Billing
The upgrade fee depends on your billing method.
Subscription
Upgrade fee = (Daily price after upgrade − Daily price before upgrade) × Remaining days to expiration
The daily price is based on the remaining days at the time of upgrade:
Fewer than 300 days remaining: monthly subscription price applies
300 or more days remaining: annual subscription price applies
Pay-as-you-go
Charges are based on the specifications of the upgraded task, billed hourly at the same rate.
For pricing details, see Billing overview.
Limitations
Upgrade direction
You can only upgrade from one-way to two-way synchronization. You cannot downgrade from two-way to one-way.
PolarDB-X 2.0
One-way synchronization between PolarDB-X 2.0 instances cannot be upgraded to two-way synchronization.
Upgrade to two-way synchronization
Go to the Data Synchronization page.
DTS console
Log on to the DTS console.
In the left-side navigation pane, click Data Synchronization.
In the upper-left corner, select the region where the task resides.
DMS console
The actual steps may vary based on the mode and layout of the DMS console. For details, see Simple mode and Customize the layout and style of the DMS console.
Log on to the DMS console.
In the top navigation bar, move the pointer over Data + AI and choose .
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, click the more options icon (...) and select Change To Two-way Sync.
In the dialog box, click OK.
After the upgrade, a reverse sync task in the Not Configured state appears below the original sync task. Configure the reverse sync task to complete the bidirectional setup.