The Splunk administrator wants to ensure data is distributed evenly amongst the indexers.

https://docs.splunk.com/Documentation/Splunk/8.2.2/Knowledge/Usedefaultfields splunk_server

The splunk server field contains the name of the Splunk server containing the event. Useful in a distributed Splunk environment. Example: Restrict a search to the main index on a server named remote. splunk_server=remote index=main 404