Some of the dtml methods being cached have dtml namespace cache keys set (no request vars are used) and appear on all accounts to being working as expected, with the expected number of enteries for these dtml
Thats could be the problem. If you pass the wrong thing to the dtml namespace cache keys you will end up in a world of pain. I suggest adding some debugging statements inside ZCacheable_set or ZDocumentTemplate_afterRender to see what that keywords dictionary you're passing in actually looks like to the the RCM. If the RCM ends up calling str() on any objects that get repr'd like <Foo instance at 6a3463> then you're going to see a lot of cache misses and spurious growth as your python process grows in size and relocates its objects in memory. This is the same problem facing PageTemplates that I wrote about last year in http://marc.theaimsgroup.com/?l=zope&m=105460381811223&w=2
Is this a possibility even when the "Entries" and "Misses" column counts are what I would expect for the possible cache key combinations from dtml? Entry counts range from 1 to approx 20, as I would expect for the possible cache keys being passed. None of the entries or misses column counts climb during testing. Does this problem occur in the background with no visible signs? Thanks for your help on this. Richard.