Qlik Replicate and Microsoft SQL Server (MS-CDC) source Endpoint: How to Startup task using stored stream position

[sureshkumar]

In certain scenarios, you may need to restart a Qlik Replicate task from a previously saved stream position, specifically a known LSN or SCN, rather than reload the entire task. This guide provides step-by-step instructions on how to resume a Microsoft SQL Server (MS-CDC) task from a stored stream position.

Steps to Start a Task from a Stored Stream Position

1. Locate the Previous Stored Stream Position
   
   Open the task log file and search for the final saved stream position. You should see an entry like the following:
   
   [SORTER          ]I: Final saved task state. Stream position 000000D8000062D00003:0:2147483647, Source id 12, next Target id 37, confirmed Target id 33, last source timestamp 1748932926987000  (sorter.c:777)
   
   In this example, the relevant stream position is: 000000D8000062D00003
   
   
   
   
2. Start the Task from This Position
   
   
   1. In the Qlik Replicate Console, open the relevant task
   2. Navigate to Task Settings --> Advanced Run Options
   3. Choose Tables are already loaded. Start processing changes from
   4. Choose Source change position (e.g. SCN or LSN) and enter the previously located Stream Position (000000D8000062D00003)
      
      
      
      
3. Validate in the Task Log
   
   

   After starting the task, check the log file to confirm that the task is starting from the specified stream position:

   [TASK_MANAGER    ]I: Task 'SQL-to-SQL__MS-CDC' running CDC only in fresh start mode, starting from log position: 'position:000000D8000062D00003'.  (replicationtask.c:1847)
   
   This confirms that Qlik Replicate is correctly picking up from the desired point in the transaction log.

   
   
   

Notes

• This method applies specifically to tasks using Microsoft SQL Server (MS-CDC) as the source.
• It is useful in scenarios such as resuming a failed task, reprocessing a limited set of changes, or disaster recovery testing.
• Always validate the stream position against the source database's current log retention to ensure the LSN is still available.

Environment

• Qlik Replicate, all versions
• SQL Server, all supported versions