Take a snapshot

You can take a snapshot of the entities in the entity cache and hold that snapshot as a potential rollback or restore point.

CacheStateManager

To work with the EntityManager's cache, use the CacheStateManager. 

Calling GetCacheState returns you an EntityCacheState that is a snapshot of the current state of the cache. You can also pass in a specific set of entities to be serialized into an EntityCacheState. You can hold on to multiple EntityCacheStates and if you need to rollback to one of them, just call RestoreCacheState.

You can also save the entity cache to a stream or file. See Save cache locally on how to do this.

EntityCacheState

The snapshot of an EntityManager's cache is called the EntityCacheState. The EntityCacheState can be restored by any EntityManager, so you can also use this to move entities between EntityManager's. Furthermore, the EntityCacheState is directly serializable so you can pass it as a parameter or object between tiers or even send it into a message queue.