persistent state for spark streaming

[Chia-Chun Shih]

Hi,

My application is to digest user logs and deduct user quotas. I need to
maintain latest states of user quotas persistently, so that latest user
quotas will not be lost.

I have tried *updateStateByKey* to generate and a DStream for user quotas
and called *persist(StorageLevel.MEMORY_AND_DISK())*, but it didn't work.

Are there better approaches to persist states for spark streaming?

Thanks.