Integrity uses several services to provide various features. These services should run under valid domain accounts, and the SQL Server roles and permissions required for these accounts depend on whether you choose to use Windows authentication or SQL Server authentication to access the Integrity database. For more information about these requirements, see Defining Your Service Accounts.
For more information about SQL Server roles and permissions, see https://msdn.microsoft.com/en-us/library/aa337562.aspx.