StateStoreProviderId — Unique Identifier of State Store Provider

StateStoreProviderId is a unique identifier of a state store provider with the following properties:

StateStoreId
Run ID of a streaming query (java.util.UUID)

In other words, StateStoreProviderId is a StateStoreId with the run ID that is different every restart.

StateStoreProviderId is used by the following execution components:

StateStoreCoordinator to track the executors of state store providers (on the driver)
StateStore object to manage state store providers (on executors)

StateStoreProviderId is created (directly or using apply factory method) when:

StateStoreRDD is requested for the placement preferences of a partition and to compute a partition
StateStoreAwareZipPartitionsRDD is requested for the preferred locations of a partition
StateStoreHandler is requested to look up a state store

Creating StateStoreProviderId — `apply` Factory Method

apply(
  stateInfo: StatefulOperatorStateInfo,
  partitionIndex: Int,
  storeName: String): StateStoreProviderId

apply simply creates a new StateStoreProviderId for the StatefulOperatorStateInfo, the partition and the store name.

Internally, apply requests the StatefulOperatorStateInfo for the checkpoint directory (aka checkpointLocation) and the stateful operator ID and creates a new StateStoreId (with the partitionIndex and storeName).

In the end, apply requests the StatefulOperatorStateInfo for the run ID of a streaming query and creates a new StateStoreProviderId (together with the run ID).

Note	`apply` is used when: `StateStoreAwareZipPartitionsRDD` is requested for the preferred locations of a partition `StateStoreHandler` is requested to look up a state store

StateStoreProviderId