History store is an internal data store of storage engines which cannot be directly controlled by application with respect to its contribution to the cache pressure. Reconciliation of a data store page either by checkpoint or eviction will not ease cache pressure much due to dirty content movement from data store to history store. As a result checkpointing could lead to tipping the cache thresholds, resulting in app thread eviction.

We need to understand the cases of cache pressure due to history store. By understanding these cases, different eviction strategies can be considered. eg: maintaining history store cache usage to data store cache usage as 1:4, or prioritising history store dirty eviction over data store dirty eviction in app threads based on the history store cache utilisation etc.,

Attached a FTDC snapshot from YCSB 100% update perf test. It seems checkpoint is triggering app thread eviction due to history store contribution to cache pressure.

Definition of done: Add stats to understand the history store contribution of cache utilization in terms of updates, dirty content and total content.