Data synchronization mode - Data Transmission Service - Alibaba Cloud Documentation Center

The data synchronization mode of Data Transmission Service (DTS) replicates ongoing changes between two data stores. This mode is typically used for OLTP-to-OLAP replications and disaster recovery-related replications.

Supported objects

Objects that can be replicated include databases, tables, and columns. You can specify objects that you want to replicate.

Advanced features


Feature	Description	References
Reselect objects to be synchronized	You can add and remove objects to be synchronized while a data synchronization task is running.	Add an object to a data synchronization task Remove an object from a data synchronization task
Track synchronization performance	You can check the performance of a data synchronization task while it is running.	View the connection status and performance of data synchronization
ETL features	Object name mapping: You can define mappings to name target objects differently from their source objects. Supported objects include databases, tables, and columns. Data filtering: You can use SQL-like queries to filter the source table to replicate only records that match certain conditions.	Specify the name of an object in the destination instance Use SQL conditions to filter data

Data synchronization task lifecycle

To fulfill a data replication process in any of the three modes, you must create a data replication task. A data replication task holds all the configurations of the replication process, such as the source database, target database, and objects to be replicated.

The following table describes the statuses of a synchronization task.


Task status	Description	Applicable operations
Prechecking	A precheck is being performed and the synchronization task has not started.	View the synchronization configurations Delete the synchronization task Duplicate synchronization configurations
Precheck Failed	The synchronization task failed to pass the precheck.	Perform the precheck View the synchronization configurations Reselect objects to be synchronized Modify the synchronization speed Delete the synchronization task Duplicate synchronization configurations
Not Started	The synchronization task has passed the precheck but is not started.	Perform the precheck Start the synchronization task Reselect objects to be synchronized Modify the synchronization speed Delete the synchronization task Duplicate synchronization configurations
Performing Initial Synchronization	The initial synchronization is in progress.	View the synchronization configurations Delete the synchronization task Duplicate synchronization configurations
Initial Synchronization Failed	Data replication has failed during initial synchronization.	View the synchronization configurations Reselect objects to be synchronized Modify the synchronization speed Delete the synchronization task Duplicate synchronization configurations
Synchronizing	The task is replicating data.	View the synchronization configurations Reselect objects to be synchronized Modify the synchronization speed Delete the synchronization task Duplicate synchronization configurations
Synchronization Failed	An error occurred during synchronization.	View the synchronization configurations Reselect objects to be synchronized Modify the synchronization speed Delete the synchronization task Duplicate synchronization configurations
Paused	The synchronization task is paused.	View the synchronization configurations Reselect objects to be synchronized Modify the synchronization speed Delete the synchronization task Duplicate synchronization configurations

A synchronization task in the Synchronization Failed or Initial Synchronization Failed status will be automatically retried multiple times within seven days of the failure occurring. To discard the data synchronization, you must manually pause or stop the synchronization task.