Implementing session persistence in the external gateway to maintain user sessions during server failovers Implementing session persistence is crucial in an external gateway setup for Tableau Server. It ensures that user sessions are maintained in the event of server failovers, thereby providing high availability and improving the user experience during unexpected disruptions. Option A is incorrect because using a different operating system for the gateway does not directly contribute to high availability or fault tolerance. Option C is incorrect as allocating additional storage to the external gateway does not necessarily impact its ability to maintain high availability or fault tolerance. Option D is incorrect because relying on a single gateway can be a point of failure; a distributed approach is typically better for fault tolerance and high availability.