org.apache.flink.runtime.state

Interface TaskLocalStateStore

All Known Subinterfaces:

OwnedTaskLocalStateStore

All Known Implementing Classes:

NoOpTaskLocalStateStoreImpl, TaskLocalStateStoreImpl

@Internal
public interface TaskLocalStateStore

Classes that implement this interface serve as a task-manager-level local storage for local checkpointed state. The purpose is to provide access to a state that is stored locally for a faster recovery compared to the state that is stored remotely in a stable store DFS. For now, this storage is only complementary to the stable storage and local state is typically lost in case of machine failures. In such cases (and others), client code of this class must fall back to using the slower but highly available store.

Method Summary

Modifier and Type	Method and Description
void	abortCheckpoint(long abortedCheckpointId) Notifies that the checkpoint with the given id was confirmed as aborted.
void	confirmCheckpoint(long confirmedCheckpointId) Notifies that the checkpoint with the given id was confirmed as complete.
LocalRecoveryConfig	getLocalRecoveryConfig() Returns the LocalRecoveryConfig for this task local state store.
void	pruneMatchingCheckpoints(java.util.function.LongPredicate matcher) Remove all checkpoints from the store that match the given predicate.
TaskStateSnapshot	retrieveLocalState(long checkpointID) Returns the local state that is stored under the given checkpoint id or null if nothing was stored under the id.
void	storeLocalState(long checkpointId, TaskStateSnapshot localState) Stores the local state for the given checkpoint id.

Method Detail

storeLocalState

void storeLocalState(@Nonnegative
                     long checkpointId,
                     @Nullable
                     TaskStateSnapshot localState)

Stores the local state for the given checkpoint id.

Parameters:

checkpointId - id for the checkpoint that created the local state that will be stored.

localState - the local state to store.

retrieveLocalState

@Nullable
TaskStateSnapshot retrieveLocalState(long checkpointID)

Returns the local state that is stored under the given checkpoint id or null if nothing was stored under the id.

Parameters:

checkpointID - the checkpoint id by which we search for local state.

Returns:

the local state found for the given checkpoint id. Can be null

getLocalRecoveryConfig

@Nonnull
LocalRecoveryConfig getLocalRecoveryConfig()

Returns the LocalRecoveryConfig for this task local state store.

confirmCheckpoint

void confirmCheckpoint(long confirmedCheckpointId)

Notifies that the checkpoint with the given id was confirmed as complete. This prunes the checkpoint history and removes all local states with a checkpoint id that is smaller than the newly confirmed checkpoint id.

abortCheckpoint

void abortCheckpoint(long abortedCheckpointId)

Notifies that the checkpoint with the given id was confirmed as aborted. This prunes the checkpoint history and removes states with a checkpoint id that is equal to the newly aborted checkpoint id.

pruneMatchingCheckpoints

void pruneMatchingCheckpoints(java.util.function.LongPredicate matcher)

Remove all checkpoints from the store that match the given predicate.

Parameters:

matcher - the predicate that selects the checkpoints for pruning.