I had the requirenment where users keep populating the data in cache and they didnt want the cache objects to expire as they dont want a delay of 8 min when the cache gets first populated(the query used to take hell lot of time)
I designed a system which keeps populating the cache with all the objects of users interest and then at night when the database is updated by another application we run a script(enclosing a java prog) which
1) Find all the objects in the cache
2) Update them from the fresh data from database
3) And the objects are ready to be used by the users with the response time as expected

Basically its a self refreshing never dying cache

I found in this forum that many people are suffering the same problem
Should anybody have interest in this solution please feel free to contact me

I will definatly post the solution

Thanks
Rahul