org.apache.flink.runtime.state.TaskLocalStateStore Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
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* See the License for the specific language governing permissions and
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*/
package org.apache.flink.runtime.state;
import org.apache.flink.annotation.Internal;
import org.apache.flink.runtime.checkpoint.TaskStateSnapshot;
import javax.annotation.Nonnegative;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.util.function.LongPredicate;
/**
* 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.
*/
@Internal
public interface TaskLocalStateStore {
/**
* Stores the local state for the given checkpoint id.
*
* @param checkpointId id for the checkpoint that created the local state that will be stored.
* @param localState the local state to store.
*/
void storeLocalState(
@Nonnegative long checkpointId,
@Nullable TaskStateSnapshot localState);
/**
* Returns the local state that is stored under the given checkpoint id or null if nothing was stored under the id.
*
* @param checkpointID the checkpoint id by which we search for local state.
* @return the local state found for the given checkpoint id. Can be null
*/
@Nullable
TaskStateSnapshot retrieveLocalState(long checkpointID);
/**
* Returns the {@link LocalRecoveryConfig} for this task local state store.
*/
@Nonnull
LocalRecoveryConfig getLocalRecoveryConfig();
/**
* 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.
*/
void confirmCheckpoint(long confirmedCheckpointId);
/**
* Remove all checkpoints from the store that match the given predicate.
* @param matcher the predicate that selects the checkpoints for pruning.
*/
void pruneMatchingCheckpoints(LongPredicate matcher);
}