Memory Only — Useful for Stateless Entities
When you select memory only mode for an entity type, instances of that entity are available only in the engine’s local JVM memory only.
These entities and their properties are not recoverable, or clustered or shared. For this reason, it is recommended that you use this mode for stateless entities only.
Memory only mode is typically used for static reference data that can be created in the rule functions on startup. It can be used also for transient utility entities that created and deleted within a single processing, and are not needed across RTC cycles.
Entities configured in memory only mode do not persist objects to the cluster and correspondingly the objects are not recovered from the cluster.
This cache mode works the same as the In Memory object management option (but is set for individual objects).
Fault tolerance limitation: Entities that use memory only cache mode are not recoverable in fault tolerance failover or failback situations.