After populating the Cache I made a call to System.gc(), no change in the memory footprint. So is there any way around this and still have an Isolation level higher than 'NONE'? If it takes 511,898,680 bytes of overhead (the space used by the 7 million objects at the top of the histo:live dump) to cache 441,115 nodes (approx 9,000,000 bytes of cached data) then we won't be able to use this system. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4161843#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...