Symptoms
Consider the following scenario:
-
You use Microsoft Sync Framework 2.1 to perform database synchronization between a Microsoft SQL Server source database and a destination database.
-
A DML operation that changes the source database data and the data synchronization operation occur at the same time.
In this scenario, non-convergence may occur between the databases.
Cause
This issue occurs because the enumeration logic detects and marks changes incorrectly if the DML operation and the data synchronization occur concurrently in a short time frame.
Snapshot transactions are internally used to determine the committed data changes. The changes that are identified are enumerated and sent to the destination database. In a short time frame, the change enumeration logic may incorrectly update the watermark to reflect all visible changes that are being processed and enumerated when the DML operation and the data synchronization occur concurrently. However, some concurrent data changes may be missed for enumeration and for propagation while the watermark is updated.
Note After you apply this hotfix, the enumeration logic correctly detects and marks only the changes that are visible, and then the changes are sent to the destination database to avoid non-convergence.
Resolution
After you apply the following hotfix, you can avoid this issue on a database that has not yet encountered the non-convergence error. However, a database that has encountered the non-convergence error is not brought into data convergence after you apply the hotfix. To resolve this issue on a database that has encountered the non-convergence error, visit the following Microsoft website to contact Microsoft Customer Service:
http://support.microsoft.com/contactus/?ws=support
Cumulative update
The hotfix for this issue was first released in Sync Framework 2.1 build 2.1.2503.00. For more information about how to obtain this hotfix package, click the following article number to view the article in the Microsoft Knowledge Base:
2531321 Description of the hotfixes that are released in Sync Framework 2.1 build 2.1.2503.00 Note Because the builds are cumulative, each new hotfix release contains all the hotfixes that were included in the previous Sync Framework 2.1 hotfix release. We recommend that you consider applying the most recent hotfix release that contains this hotfix. For more information about the builds that were released after Sync Framework 2.1 was released, click the following article number to view the article in the Microsoft Knowledge Base:
2531326 Description of the Sync Framework 2.1 builds that were released after Sync Framework 2.1 was released
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
For more information about Sync Framework, visit the following MSDN website:
