After Data Transmission Service (DTS) completes a data verification task, review the results to confirm data consistency between the source and destination databases and resolve any inconsistencies.
Prerequisites
Before you begin, ensure that you have:
A created and configured data verification task. For more information, see Configure a data verification task
Navigate to verification details
Access verification details from either the Data Verification page or from within a synchronization or migration instance.
From the Data Verification page
Open the Data Verification page using one of the following methods:
DTS console (quick start)
Go to the Data Verification page.
Optional: In the top navigation bar, select the region where the data verification instance resides.
DTS console
Log on to the DTS console.
In the left-side navigation pane, click Data Verification.
Optional: In the top navigation bar, select the region where the data verification instance resides.
DMS console
NoteThe actual operations may vary based on the mode and layout of the Data Management (DMS) console. For more information, see Simple mode and Customize the layout and style of the DMS console.
Log on to the DMS console.
In the top navigation bar, choose Data + AI > DTS (DTS) > Data Verification.
Optional: On the right side of Verification Task, select the region where the data verification instance resides.
Click the instance ID to open the instance details page.
Optional: In the left-side pane, click Task Management.
In the Progress section, click the Full Data Verification, Incremental Data Verification, or Schema Verification module.
From a synchronization or migration instance
Open the Data Synchronization or Data Migration page using one of the following methods:
DTS console
Log on to the DTS console.
In the left-side navigation pane, click Data Synchronization or Data Migration.
Optional: In the top navigation bar, select the region where the instance resides.
DMS console
NoteThe actual operations may vary based on the mode and layout of the Data Management (DMS) console. For more information, see Simple mode and Customize the layout and style of the DMS console.
Log on to the DMS console.
In the top navigation bar, choose Data + AI > DTS (DTS) > Data Synchronization or Data + AI > DTS (DTS) > Data Migration.
Optional: On the right side of Data Synchronization or Data Migration, select the region where the instance resides.
Click the task ID to open the task details page.
Optional: In the left-side pane, click Task Management.
Clear Hide Completed Modules next to Progress.
In the Progress section, click the Full Data Verification, Incremental Data Verification, or Schema Verification module.
Understand verification results
Each verification module has two tabs: Basic Information for task state, and Check Details for detailed results.
For full data verification and schema verification, view details after the Status reaches Completed.
For incremental data verification, view details after the Current Offset passes the point in time when incremental data was last changed.
Basic Information tab
The Basic Information tab shows the start time, verification time rules, status, actions, and error messages.
The Status on this tab indicates the operational state of the verification task (for example, running or completed), not the verification results. To check whether data is consistent, go to the Check Details tab.
After data verification starts, manage the task by clicking Restart, Pause, Stop, or Delete next to Actions. For details, see Manage verification tasks.
Check Details tab
The Check Details tab displays verification results for each table, including source and destination database names, table names, verification state, and verification timestamp.
Results are sorted in descending order by the Number of Inconsistent Records column.
Key columns:
| Column | Description |
|---|---|
| Total Number of Records | Estimated number of records to verify. |
| Number of records completed by verification | Actual number of verified records. This value may exceed Total Number of Records because the total is an estimate. |
| Number of Inconsistent Records | Number of records where source and destination data differ. |
Interpret the results:
Number of Inconsistent Records is 0: Data is consistent between the source and destination objects. You do not need to view or download the data verification report because the report does not contain data.
Number of Inconsistent Records is not 0: Inconsistencies exist between source and destination. In the Actions column, click one of the following:
View Report -- Review inconsistency details in the console.
Download Report -- Download the verification report for offline analysis.
Download Revised SQL Statements -- Download SQL statements to correct inconsistent data in the destination database.
ImportantExecute DELETE statements in the revised SQL with caution.
Revised SQL statements are available only for full data verification results.
If full data verification was started before 14:04:52 on November 20, 2023, you must restart full data verification before you can download revised SQL statements.
Data retention and re-verification behavior
Data retention: By default, the information about data inconsistency that is detected by full data verification tasks and incremental data verification tasks are retained for 30 days. Review and resolve inconsistencies promptly.
Record merging in incremental verification: During incremental data verification, DTS merges changes to the same record within a time window. As a result, the displayed record count may be lower than the actual number of incremental changes.
Re-verification behavior:
Full data verification: If inconsistent data is found, after you manually correct the data, you must manually verify or execute the task again to authenticate data consistency.
Incremental data verification: DTS re-verifies the inconsistent data approximately every 10 minutes. This interval is extended when a large volume of inconsistent data exists.
Manage verification tasks
After reviewing results, manage full data verification and incremental data verification tasks from the Basic Information tab.
The following operations do not apply to schema verification.
A dimmed button means the operation is not available in the current task state.
Releasing a verification task from the verification task list also releases it from the corresponding synchronization or migration instance.
Procedure
Go to the Task Management page of your DTS task.
Clear Hide Completed Modules next to Progress.
Click the Full Data Verification or Incremental Data Verification module.
Optional: Click the Basic Information tab.
Perform one of the following operations:
Pause
Pause is available only after verification starts.
After full data verification is paused, the Status changes to Completed. Full data verification does not support resumable verification.
Click Pause next to Actions. In the Note dialog, click OK. The task Status changes to Pausing.
Restart
Restart full data verification when the Status is Pausing or Completed. After full data verification is restarted, DTS verifies the existing data in the source and destination databases.
Restart incremental data verification when the Status is Pausing or Completed.
Click Restart next to Actions. In the Note dialog, click OK.
Stop
Stop applies only to incremental data verification. After the task is stopped, the Status changes to Completed.
Click Stopped next to Actions. In the Note dialog, click OK.
Delete
A deleted verification task cannot be recovered. You must configure another data verification task.
Click Delete next to Actions. In the Note dialog, click OK.
Related API operations
| Operation | Description |
|---|---|
| DescribeDataCheckTableDiffDetails | Query inconsistent data detected in a specific table. |
| DescribeDataCheckReportUrl | Get the download URL for a data verification report. |
| DescribeDataCheckTableDetails | Query details of a full or incremental data verification task. |
FAQ
How do I create a full or incremental data verification task?
Use one of the following methods:
Go to the Data Verification page and create a task. Note that incremental data verification tasks cannot be created from this page.
Open the Data Synchronization or Data Migration page. Select the instance, click the Full Data Verification or Incremental Data Verification module, click Delete on the Basic Information tab, and then click Create Verification Task in the upper part of the page.
Data verification is not supported for DTS instances with a Status of Completed.
Why hasn't full or incremental data verification started?
The trigger depends on whether the task includes an incremental data synchronization or migration stage:
Without incremental stage: Full data verification starts after full data is written to the destination database.
With incremental stage (single task): Verification starts when incremental data reaches the destination without latency for the first time.
With incremental stage (multiple subtasks): Verification starts when the latency of all subtasks drops below 2 seconds. For example, incremental data migration between MongoDB databases runs as multiple subtasks.
Full data verification and incremental data verification do not affect each other.
Why is the incremental data verification result empty?
Incremental data verification only records information about databases and tables that contain inconsistent data. If all incremental data is consistent between source and destination, the result is empty.
Why isn't the offset in the incremental verification module updating?
The Current Offset shows the timestamp of the most recent incremental data verification. If no new incremental data is generated in the source database, the offset stays unchanged or may not appear.
Why is no inconsistency detected after writing incremental data to the destination?
Incremental data verification checks consistency based on the source database. Inconsistencies are detected only when incremental data generated in the source database is either missing from the destination or differs from the source.