1 Reply Latest reply on Dec 4, 2017 4:44 PM by aaron.blalack

    Tableau Data Engine Error: 40705

    Matt Michaelson

      I receive this error in Tableau Desktop after clicking the Update Now button in the Edit Data Source window. 

       

      Also, when trying to create an extract, no data is imported and a message box appears asking "Reconnect to (data source name)".  If I click Yes, it simply returns to the workbook and maintains a live connection.

       

      My data source consists of cross-database joins between Progress OpenEdge and Microsoft SQL Server databases.  This combination of databases has worked in the past, so I'm not sure why it's not working now.

       

      I've tried recreating the data source from scratch in a new workbook and the error still appears.

       

      Has anyone encountered this issue?  If so, what was the resolution?

       

      I am using Tableau Desktop 10.4.1 (64-bit)

        • 1. Re: Tableau Data Engine Error: 40705
          aaron.blalack

          Hi Matt!

           

          Tableau Data Engine Error 40705 typically indicates that Tableau has run out of resources to finish creating the extract. Tableau is able to create and handle fairly large extracts, however, there can often be physical and theoretical practical limits to the size of extracts.

           

          1. Launch a Command Prompt as an Administrator
          2. Navigate to the Tableau Server \bin directory
          3. Run tabadmin cleanup (more information about this command may be found here: https://onlinehelp.tableau.com/current/server/en-us/tabadmin_cleanup.htm )
          4. If possible, find more opportunities to clear up disk space on the Tableau Server machine.

           

          Please let me know if these steps resolve the issue for you For more background on this issue, I'll quote a colleague of mine because their write-up is quite good and concise:

          In terms of physical limitations, when creating the extract, the Temp directory, which is where an extract is stored during creation or a refresh, may require disk space up to the square of the final file size of the extract. If you're running low on space, this would account for the behavior you're seeing. The amount of available RAM may also limit the size of extracts that can be created. While the full data set is never loaded entirely into memory, creating extracts and querying extracts utilizes the local machine RAM and disk. These resources can be exhausted before the theoretical practical extract size limit, particularly if the data set is very large. Additionally, the space required to create an extract goes up exponentially when joins are involved.

           

          This can also be caused by excessive memory fragmentation. When Tableau requests memory, it must be able to address the full size requested as a contiguous block. The memory requested must be contiguous, which is why some machines with a lot of available memory may see “out of memory” errors if the contiguous address space is not available.

           

          For more detailed information about when to use an extract over a live connection, please see the following article:

           

          In-Memory or Live Data: Which Is Better?

          https://www.tableau.com/learn/whitepapers/memory-or-live-data