How many default VizQL process instances are established in Tableau Server?

The correct response indicates that the default number of VizQL process instances is established as equal to the number of cores divided by 4, with a maximum cap of 4 instances. This setup is designed to optimize resource allocation and ensure efficient processing of visual queries within Tableau Server.

The rationale for this configuration is rooted in system performance and resource management. By dividing the number of cores by 4, Tableau ensures that it does not overwhelm the server with too many VizQL processes, which could degrade performance due to excessive resource consumption. Additionally, the maximum threshold of 4 ensures that even on systems with very high core counts, the number of processes remains manageable and optimal for handling requests. This balance helps maintain responsiveness while accommodating varying workloads.

Understanding the core-to-process relationship assists in effectively sizing Tableau Server installations, particularly in environments that expect fluctuating levels of user activity.