org.apache.flink.runtime.state.TaskStateManager Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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*
* http://www.apache.org/licenses/LICENSE-2.0
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*/
package org.apache.flink.runtime.state;
import org.apache.flink.runtime.checkpoint.CheckpointMetaData;
import org.apache.flink.runtime.checkpoint.CheckpointMetrics;
import org.apache.flink.runtime.checkpoint.PrioritizedOperatorSubtaskState;
import org.apache.flink.runtime.checkpoint.TaskStateSnapshot;
import org.apache.flink.runtime.jobgraph.OperatorID;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
/**
* This interface provides methods to report and retrieve state for a task.
*
* When a checkpoint or savepoint is triggered on a task, it will create snapshots for all stream operator instances
* it owns. All operator snapshots from the task are then reported via this interface. A typical implementation will
* dispatch and forward the reported state information to interested parties such as the checkpoint coordinator or a
* local state store.
*
*
This interface also offers the complementary method that provides access to previously saved state of operator
* instances in the task for restore purposes.
*/
public interface TaskStateManager extends CheckpointListener {
/**
* Report the state snapshots for the operator instances running in the owning task.
*
* @param checkpointMetaData meta data from the checkpoint request.
* @param checkpointMetrics task level metrics for the checkpoint.
* @param acknowledgedState the reported states to acknowledge to the job manager.
* @param localState the reported states for local recovery.
*/
void reportTaskStateSnapshots(
@Nonnull CheckpointMetaData checkpointMetaData,
@Nonnull CheckpointMetrics checkpointMetrics,
@Nullable TaskStateSnapshot acknowledgedState,
@Nullable TaskStateSnapshot localState);
/**
* Returns means to restore previously reported state of an operator running in the owning task.
*
* @param operatorID the id of the operator for which we request state.
* @return Previous state for the operator. The previous state can be empty if the operator had no previous state.
*/
@Nonnull
PrioritizedOperatorSubtaskState prioritizedOperatorState(OperatorID operatorID);
/**
* Returns the configuration for local recovery, i.e. the base directories for all file-based local state of the
* owning subtask and the general mode for local recovery.
*/
@Nonnull
LocalRecoveryConfig createLocalRecoveryConfig();
}