Hello Vijayalakshmi Shanmugam,
What is the data source involved with this issue? I suggest checking a few things first,
a) make sure you have the latest Tableau drivers and version installed for both Tableau Desktop and Server
b) double check the incremental refresh settings when publishing the workbook to Server.
If the issue occurs again, contact Tableau Support for assistance with logs and as much detail as possible to assist in a quick resolution of the issue. Data source type, date/time of issue, and version information will be requested by support to investigate.