What is the default number of backgrounder instances in Tableau Server if there are fewer than 8 cores?

The default number of backgrounder instances in Tableau Server is set based on the number of CPU cores available. When the server has fewer than 8 cores, the default configuration assigns 2 backgrounder instances. This allocation allows Tableau Server to efficiently manage the workload associated with scheduling and running background tasks, including extract refreshes and subscription deliveries, while balancing the resource usage with available processing power.

Having two instances ensures that there is redundancy and improved performance, allowing the server to handle multiple tasks simultaneously without overwhelming the available resources. This setup is particularly important in environments where data processing demands can fluctuate, as it helps maintain a smooth operational flow even under varying loads.

In a case where there are fewer than 8 cores, having 1 instance might limit the ability to scale or manage tasks effectively, while allocating 4 or 8 instances could lead to resource contention, reducing overall system performance. Therefore, the choice of 2 instances strikes an optimal balance for Tableau Server's efficiency and performance in such configurations.