org.apache.flink.runtime.checkpoint.StandaloneCompletedCheckpointStore 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,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.flink.runtime.checkpoint;
import org.apache.flink.runtime.jobmanager.RecoveryMode;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.List;
import static org.apache.flink.util.Preconditions.checkArgument;
import static org.apache.flink.util.Preconditions.checkNotNull;
/**
* {@link CompletedCheckpointStore} for JobManagers running in {@link RecoveryMode#STANDALONE}.
*/
class StandaloneCompletedCheckpointStore implements CompletedCheckpointStore {
/** The maximum number of checkpoints to retain (at least 1). */
private final int maxNumberOfCheckpointsToRetain;
/** User class loader for discarding {@link CompletedCheckpoint} instances. */
private final ClassLoader userClassLoader;
/** The completed checkpoints. */
private final ArrayDeque checkpoints;
/**
* Creates {@link StandaloneCompletedCheckpointStore}.
*
* @param maxNumberOfCheckpointsToRetain The maximum number of checkpoints to retain (at
* least 1). Adding more checkpoints than this results
* in older checkpoints being discarded.
* @param userClassLoader The user class loader used to discard checkpoints
*/
public StandaloneCompletedCheckpointStore(
int maxNumberOfCheckpointsToRetain,
ClassLoader userClassLoader) {
checkArgument(maxNumberOfCheckpointsToRetain >= 1, "Must retain at least one checkpoint.");
this.maxNumberOfCheckpointsToRetain = maxNumberOfCheckpointsToRetain;
this.userClassLoader = checkNotNull(userClassLoader, "User class loader");
this.checkpoints = new ArrayDeque<>(maxNumberOfCheckpointsToRetain + 1);
}
@Override
public void recover() throws Exception {
// Nothing to do
}
@Override
public void addCheckpoint(CompletedCheckpoint checkpoint) throws Exception {
checkpoints.addLast(checkpoint);
if (checkpoints.size() > maxNumberOfCheckpointsToRetain) {
checkpoints.removeFirst().discard(userClassLoader);
}
}
@Override
public CompletedCheckpoint getLatestCheckpoint() {
return checkpoints.isEmpty() ? null : checkpoints.getLast();
}
@Override
public List getAllCheckpoints() {
return new ArrayList<>(checkpoints);
}
@Override
public int getNumberOfRetainedCheckpoints() {
return checkpoints.size();
}
@Override
public void shutdown() throws Exception {
for (CompletedCheckpoint checkpoint : checkpoints) {
checkpoint.discard(userClassLoader);
}
checkpoints.clear();
}
@Override
public void suspend() throws Exception {
// Do a regular shutdown, because we can't recovery anything
shutdown();
}
}