As an ejb-timer persistence there are current only
- file; local not shared and no clustering possible
- database; shareable possible to use cluster features
But sometimes a project does not need a relational database but there are NoSQL storages available.
Because of this it would be a benefit to add the ability for such Object databases like MongoDb, AWS dynamo and Infinispan.
It would be a plus if there is no need to have an extra RDBMS to persist timers