KB4521739 - FIX: Error occurs when CDC capture process tries to insert duplicate key in table "cdc.lsn_time_mapping" in SQL Server 2016, 2017 and 2019

Applies to: SQL Server 2016 Service Pack 2SQL Server 2016 DeveloperSQL Server 2016 Enterprise


Assume that Change Data Capture (CDC) is enabled in Microsoft SQL Server 2016, 2017 or 2019. Because of a timing issue, CDC capture process may try to insert duplicate start_lsn in the table cdc.lsn_time_mapping, and you may receive an error message that resembles the following:
Violation of PRIMARY KEY constraint 'lsn_time_mapping_clustered_idx'. Cannot insert duplicate key in object 'cdc.lsn_time_mapping'. The duplicate key value is (Value).


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. 


This issue is fixed in the following cumulative updates for SQL Server:
Note: For this fix to take effect, you need to enable the Trace Flag (TF) 8291.
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