If you have cached the information link(Information designer >> Information link >> caching) then the corresponding cache entry gets created inside the Attachment Manager(Spotfire Server Installation Directory\X.X\tomcat\temp\AttachmentManager) folder.
The cache settings from TIBCO Spotfire Configuration Tool >> Configuration tab >> Attachment Manager apply here.

How to verify that data is coming from cached information link.

All Supported OS

When the cached information link (not of type on-demand) is executed the first time or after timeout, the SQL and the execution details will be updated in the <Spotfire Server Install>\tomcat\logs\sql.log file. No further updates are made in the Sql.log until the cache timeout period.

To check if the cache is being used, execute the information link and check the "Metadata loaded" entry in the <Spotfire Server Install>\tomcat\logs\Library.log file.

Example: 10.98.60.119;37;1;2017-08-20T20:06:37,128+0530;Metadata loaded;Table_1;spotfire.query;1323;38a30b33-f40e-4e90-ac09-387bbade5c3f

where the GUID-"38a30b33-f40e-4e90-ac09-387bbade5c3f" is related to the cached information link.
Note: To find the GUID of the information link, go to Information Designer>>Right Click on the Information Link>>Copy ID

Note: 1) Information Link caching will not work if you have a personalized information link.

2) It will also not work for on-demand data tables(information link). Even though the information link caching might be configured on the Information link used for the on-demand data table, this will not take effect for the queries used by this table. The reason for this is that on-demand tables, on the server side, works differently. The server looks at the original information link, re-works this and creates a temporary instance that does not have any ID and it is as designed that the caching should only take place for information links having an ID.

https://docs.tibco.com/pub/sfire-analyst/7.11.0/doc/html/en-US/TIB_sfire-analyst_UsersGuide/id/id_information_link_tab.htm