Wow. Outstanding. Thanks so much for the reply. It did bring about almost an order of magnitude improvement! I tweaked the settings a bit more so I ended up using 10000 (instead of 50000) for the delete history.
The new setting for IGNITE_ATOMIC_CACHE_DELETE_HISTORY_SIZE brought down the total heap to ~420MB (60% reduction from 1GB). And after applying the setting for affinity it came down to ~200MB, which is perfectly acceptable. I will do a bit more tuning but we're where we want to be in terms of heap footprint already. The final question then is, where can I find more documentation about what these settings do and what they really control so we can understand the potential side-effects/cons of using these non-default settings. Again, thanks so much for your prompt reply and help! <http://apache-ignite-users.70518.x6.nabble.com/file/n3691/ignite_cache_node_heap_timeline_new_DELETE_HISTORY_SIZE.png> <http://apache-ignite-users.70518.x6.nabble.com/file/n3691/ignite_cache_node_heap_timeline_new_DELETE_HISTORY_SIZE_and_AFFINITY.png> -- View this message in context: http://apache-ignite-users.70518.x6.nabble.com/Ignite-Cache-High-Memory-Overhead-caused-by-GridCircularBuffer-Item-instances-tp3682p3691.html Sent from the Apache Ignite Users mailing list archive at Nabble.com.