You can use a dedicated Active Directory (AD) user account for the Tableau Server service to run under, called a Run As User account. Some administrators choose to do this when published workbooks on Tableau Server connect to live data sources. The server's default Network Service account (NT AUTHORITY\NetworkService) doesn't have the correct permissions for connecting to data sources on other computers. A correctly configured AD account does.
For data sources that require NT authentication, the AD account can also automatically handle the authentication process, thus shielding users from prompts for credentials when the workbook connects to the live data source. Finally, a Run As User AD account that is dedicated to a specific resource is often less problematic to manage than an AD account associated with a person.
To configure Tableau Server to use a Run As User account, follow the procedures below. The steps under Run As Account Settings to Confirm may vary from site to site.
If you are installing Tableau Server with your Run As User account in hand, before you run Setup, confirm that the Windows Secondary Login service has the correct values for Log On and Startup. See Verifying Tableau Service Settings for more information.