org.apache.flink.runtime.state.gemini.internal.GeminiKeyedStateHandle 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
* 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
* limitations under the License.
*/
package org.apache.flink.runtime.state.gemini.internal;
import org.apache.flink.core.fs.FSDataInputStream;
import org.apache.flink.core.fs.Path;
import org.apache.flink.core.memory.DataInputViewStreamWrapper;
import org.apache.flink.core.memory.DataOutputViewStreamWrapper;
import org.apache.flink.runtime.state.KeyGroupRange;
import org.apache.flink.runtime.state.KeyedStateHandle;
import org.apache.flink.runtime.state.SharedStateRegistry;
import org.apache.flink.runtime.state.StreamStateHandle;
import org.apache.flink.runtime.state.gemini.engine.snapshot.DBSnapshotMeta;
import org.apache.flink.runtime.state.gemini.engine.snapshot.DBSnapshotMetaSerializer;
import org.apache.flink.util.Preconditions;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.util.Objects;
/**
* A state handle used by JM.
*/
public class GeminiKeyedStateHandle extends AbstractGeminiKeyedStateHandle implements StreamStateHandle {
private static final Logger LOG = LoggerFactory.getLogger(GeminiKeyedStateHandle.class);
private static final long serialVersionUID = 1L;
/**
* Once the shared states are registered, it is the {@link SharedStateRegistry}'s
* responsibility to cleanup those shared states.
* But in the cases where the state handle is discarded before performing the registration,
* the handle should delete all the shared states created by it.
*
* his variable is not null iff the handles was registered.
*/
private transient SharedStateRegistry sharedStateRegistry;
public GeminiKeyedStateHandle(
final long checkpointId,
final KeyGroupRange keyGroupRange,
final StreamStateHandle metaStateHandle,
final DirectoryStreamStateHandle dbSnapshotDirectoryHandle,
final DBSnapshotMeta dbSnapshotMeta
) {
super(checkpointId, keyGroupRange, metaStateHandle, dbSnapshotDirectoryHandle, dbSnapshotMeta);
}
@Override
public KeyedStateHandle getIntersection(KeyGroupRange otherKeyGroupRange) {
return KeyGroupRange.EMPTY_KEY_GROUP_RANGE.equals(
this.keyGroupRange.getIntersection(otherKeyGroupRange)) ? null : this;
}
@Override
public void registerSharedStates(SharedStateRegistry stateRegistry) {
// This is a quick check to avoid that we register twice with the same registry. However, the code allows to
// register again with a different registry. The implication is that ownership is transferred to this new
// registry. This should only happen in case of a restart, when the CheckpointCoordinator creates a new
// SharedStateRegistry for the current attempt and the old registry becomes meaningless. We also assume that
// an old registry object from a previous run is due to be GCed and will never be used for registration again.
Preconditions.checkState(
sharedStateRegistry != stateRegistry,
"The state handle has already registered its shared states to the given registry.");
sharedStateRegistry = Preconditions.checkNotNull(stateRegistry);
LOG.trace("Registering GeminiKeyedStateHandle for checkpoint {} from backend.", checkpointId);
// TODO how to deal with dbSnapshotDirectoryHandle for rescaling
}
@Override
public void discardState() throws Exception {
SharedStateRegistry registry = this.sharedStateRegistry;
final boolean isRegistered = (registry != null);
LOG.trace("Discarding GeminiKeyedStateHandle (registered = {}) for checkpoint {} from backend.",
isRegistered,
checkpointId);
try {
metaStateHandle.discardState();
} catch (Exception e) {
LOG.warn("Could not properly discard meta data.", e);
}
// TODO how to deal with dbSnapshotDirectoryHandle for rescaling
}
@Override
public FSDataInputStream openInputStream() throws IOException {
Preconditions.checkNotNull(metaStateHandle, "metaStateHandle is null");
return metaStateHandle.openInputStream();
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
GeminiKeyedStateHandle that = (GeminiKeyedStateHandle) o;
return checkpointId == that.checkpointId &&
Objects.equals(keyGroupRange, that.keyGroupRange) &&
Objects.equals(metaStateHandle, that.metaStateHandle) &&
Objects.equals(dbSnapshotDirectoryHandle, that.dbSnapshotDirectoryHandle) &&
Objects.equals(dbSnapshotMeta, that.dbSnapshotMeta);
}
@Override
public int hashCode() {
int result = Objects.hashCode(keyGroupRange);
result = 31 * result + (int) (getCheckpointId() ^ (getCheckpointId() >>> 32));
result = 31 * result + Objects.hashCode(metaStateHandle);
result = 31 * result + Objects.hashCode(dbSnapshotDirectoryHandle);
result = 31 * result + Objects.hashCode(dbSnapshotMeta);
return result;
}
@Override
public String toString() {
return "GeminiKeyedStateHandle {" +
", checkpointId=" + checkpointId +
", keyGroupRange=" + keyGroupRange +
", metaStateHandle=" + metaStateHandle +
", dbSnapshotDirectoryHandle=" + dbSnapshotDirectoryHandle +
", dbSnapshotMeta=" + dbSnapshotMeta +
"}";
}
public static void serializeDBPart(
GeminiKeyedStateHandle stateHandle,
DataOutputStream dos) throws IOException {
String dbSnapshotDirectory =
stateHandle.getDBSnapshotDirectoryHandle().getDirectory().toUri().toString();
dos.writeUTF(dbSnapshotDirectory);
DBSnapshotMeta dbSnapshotMeta = stateHandle.getDBSnapshotMeta();
DBSnapshotMetaSerializer.INSTANCE.serialize(dbSnapshotMeta, new DataOutputViewStreamWrapper(dos));
}
public static GeminiKeyedStateHandle deserializeDBPartAndCreateStateHandle(
long checkpointId,
KeyGroupRange keyGroupRange,
StreamStateHandle metaStateHandle,
DataInputStream dis) throws IOException {
String dbSnapshotDirectory = dis.readUTF();
DBSnapshotMeta dbSnapshotMeta =
DBSnapshotMetaSerializer.INSTANCE.deserialize(new DataInputViewStreamWrapper(dis));
return new GeminiKeyedStateHandle(
checkpointId,
keyGroupRange,
metaStateHandle,
new DirectoryStreamStateHandle(new Path(dbSnapshotDirectory)),
dbSnapshotMeta);
}
}