Sp2 - Jahia link cache: JahiaLinkManagerCachefindByTypeAndLeftObjectKey does not seem to work

I clikced on the versioning tab on the home page of the 10'000 pages test site. This took 3 hours to calcultate all the workflow states and parse all the sub-obeject of content.

When I go into the cache stats page in the admin center, it looks like the JahiaLinkManagerCachefindByTypeAndLeftObjectKey is not use at all but several hits were done into this one (cf screenshot). Normal?