org.apache.flink.runtime.state.ManagedSnapshotContext Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
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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.PublicEvolving;
/**
* This interface provides a context in which operators that use managed state (i.e. state that is
* managed by state backends) can perform a snapshot. As snapshots of the backends themselves are
* taken by the system, this interface mainly provides meta information about the checkpoint.
*/
@PublicEvolving
public interface ManagedSnapshotContext {
/**
* Returns the ID of the checkpoint for which the snapshot is taken.
*
* The checkpoint ID is guaranteed to be strictly monotonously increasing across checkpoints.
* For two completed checkpoints A and B, {@code ID_B > ID_A} means that
* checkpoint B subsumes checkpoint A, i.e., checkpoint B contains a later
* state than checkpoint A.
*/
long getCheckpointId();
/**
* Returns timestamp (wall clock time) when the master node triggered the checkpoint for which
* the state snapshot is taken.
*/
long getCheckpointTimestamp();
}