Can Spotlight continue to collect if the diagnostic server goes down?
If justa client (GUI) goes down and Diagnostic Server is on a separate machine it will continuously performs the collection of Spotlight data. The collected data can then be displayed whenever a Spotlight client is started on a machine that has access to the specified Diagnostic Server.
If the Diagnostic Server goes down, there no way for Spotlight to continue to display data. Since there would be no more data collected, there would be no way for Spotlight to continue displaying data.
If just the service goes down, the data is cllected into flat file for some time and then applied once the QDS service is up.