Which process is known to enhance performance by running additional instances?

The process that enhances performance by running additional instances is the Backgrounder. This service operates behind the scenes in Tableau Server to manage tasks that occur asynchronously, such as refreshing extracts, running subscriptions, and executing scheduled tasks. By enabling multiple instances of background processes, it allows the server to handle numerous tasks concurrently without impacting the performance of user interactions with the Tableau interface. This scalability helps to optimize the workload on the server, ensuring that multiple queued jobs can be processed in an efficient manner, thus improving overall performance and response times.

The Cluster Controller manages the distribution of tasks across nodes in a clustered environment but does not specifically enhance performance by adding instances; rather, it coordinates the activities between them. The Metrics Service collects and processes data about user interactions and system performance but does not directly run additional instances to enhance performance. The Resource Monitor is responsible for tracking resource usage across the server but does not enhance performance by running additional instances either.