org.apache.flink.runtime.state.IncrementalRemoteKeyedStateHandle 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.state;
import org.apache.flink.annotation.VisibleForTesting;
import org.apache.flink.util.Preconditions;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.annotation.Nonnull;
import java.nio.charset.StandardCharsets;
import java.util.List;
import java.util.UUID;
import java.util.stream.Collectors;
/**
* The handle to states of an incremental snapshot.
*
* The states contained in an incremental snapshot include:
*
*
* - Created shared state which includes shared files produced since the last completed
* checkpoint. These files can be referenced by succeeding checkpoints if the checkpoint
* succeeds to complete.
*
- Referenced shared state which includes the shared files materialized in previous
* checkpoints. Until we this is registered to a {@link SharedStateRegistry}, all referenced
* shared state handles are only placeholders, so that we do not send state handles twice from
* which we know that they already exist on the checkpoint coordinator.
*
- Private state which includes all other files, typically mutable, that cannot be shared by
* other checkpoints.
*
- Backend meta state which includes the information of existing states.
*
*
* When this should become a completed checkpoint on the checkpoint coordinator, it must first be
* registered with a {@link SharedStateRegistry}, so that all placeholder state handles to
* previously existing state are replaced with the originals.
*
* IMPORTANT: This class currently overrides equals and hash code only for testing purposes. They
* should not be called from production code. This means this class is also not suited to serve as a
* key, e.g. in hash maps.
*/
public class IncrementalRemoteKeyedStateHandle implements IncrementalKeyedStateHandle {
public static final long UNKNOWN_CHECKPOINTED_SIZE = -1L;
private static final Logger LOG =
LoggerFactory.getLogger(IncrementalRemoteKeyedStateHandle.class);
private static final long serialVersionUID = -8328808513197388231L;
/**
* UUID to identify the backend which created this state handle. This is in creating the key for
* the {@link SharedStateRegistry}.
*/
private final UUID backendIdentifier;
/** The key-group range covered by this state handle. */
private final KeyGroupRange keyGroupRange;
/** The checkpoint Id. */
private final long checkpointId;
/** Shared state in the incremental checkpoint. */
private final List sharedState;
/** Private state in the incremental checkpoint. */
private final List privateState;
/** Primary meta data state of the incremental checkpoint. */
private final StreamStateHandle metaStateHandle;
private final long persistedSizeOfThisCheckpoint;
private final StateHandleID stateHandleId;
/**
* 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.
*
* This variable is not null iff the handles was registered.
*/
private transient SharedStateRegistry sharedStateRegistry;
@VisibleForTesting
public IncrementalRemoteKeyedStateHandle(
UUID backendIdentifier,
KeyGroupRange keyGroupRange,
long checkpointId,
List sharedState,
List privateState,
StreamStateHandle metaStateHandle) {
this(
backendIdentifier,
keyGroupRange,
checkpointId,
sharedState,
privateState,
metaStateHandle,
UNKNOWN_CHECKPOINTED_SIZE,
new StateHandleID(UUID.randomUUID().toString()));
}
public IncrementalRemoteKeyedStateHandle(
UUID backendIdentifier,
KeyGroupRange keyGroupRange,
long checkpointId,
List sharedState,
List privateState,
StreamStateHandle metaStateHandle,
long persistedSizeOfThisCheckpoint) {
this(
backendIdentifier,
keyGroupRange,
checkpointId,
sharedState,
privateState,
metaStateHandle,
persistedSizeOfThisCheckpoint,
new StateHandleID(UUID.randomUUID().toString()));
}
protected IncrementalRemoteKeyedStateHandle(
UUID backendIdentifier,
KeyGroupRange keyGroupRange,
long checkpointId,
List sharedState,
List privateState,
StreamStateHandle metaStateHandle,
long persistedSizeOfThisCheckpoint,
StateHandleID stateHandleId) {
this.backendIdentifier = Preconditions.checkNotNull(backendIdentifier);
this.keyGroupRange = Preconditions.checkNotNull(keyGroupRange);
this.checkpointId = checkpointId;
this.sharedState = Preconditions.checkNotNull(sharedState);
this.privateState = Preconditions.checkNotNull(privateState);
this.metaStateHandle = Preconditions.checkNotNull(metaStateHandle);
this.sharedStateRegistry = null;
this.persistedSizeOfThisCheckpoint =
persistedSizeOfThisCheckpoint == UNKNOWN_CHECKPOINTED_SIZE
? getStateSize()
: persistedSizeOfThisCheckpoint;
this.stateHandleId = stateHandleId;
}
public static IncrementalRemoteKeyedStateHandle restore(
UUID backendIdentifier,
KeyGroupRange keyGroupRange,
long checkpointId,
List sharedState,
List privateState,
StreamStateHandle metaStateHandle,
long persistedSizeOfThisCheckpoint,
StateHandleID stateHandleId) {
return new IncrementalRemoteKeyedStateHandle(
backendIdentifier,
keyGroupRange,
checkpointId,
sharedState,
privateState,
metaStateHandle,
persistedSizeOfThisCheckpoint,
stateHandleId);
}
@Override
public KeyGroupRange getKeyGroupRange() {
return keyGroupRange;
}
@Override
public long getCheckpointId() {
return checkpointId;
}
@Override
public CheckpointBoundKeyedStateHandle rebound(long checkpointId) {
return new IncrementalRemoteKeyedStateHandle(
backendIdentifier,
keyGroupRange,
checkpointId,
sharedState,
privateState,
metaStateHandle,
persistedSizeOfThisCheckpoint,
stateHandleId);
}
public List getSharedState() {
return sharedState;
}
public List getPrivateState() {
return privateState;
}
public StreamStateHandle getMetaStateHandle() {
return metaStateHandle;
}
@Nonnull
public UUID getBackendIdentifier() {
return backendIdentifier;
}
@Nonnull
@Override
public List getSharedStateHandles() {
return getSharedState();
}
public SharedStateRegistry getSharedStateRegistry() {
return sharedStateRegistry;
}
@Override
public KeyedStateHandle getIntersection(KeyGroupRange keyGroupRange) {
return KeyGroupRange.EMPTY_KEY_GROUP_RANGE.equals(
this.keyGroupRange.getIntersection(keyGroupRange))
? null
: this;
}
@Override
public StateHandleID getStateHandleId() {
return stateHandleId;
}
@Override
public void discardState() throws Exception {
SharedStateRegistry registry = this.sharedStateRegistry;
final boolean isRegistered = (registry != null);
LOG.trace(
"Discarding IncrementalRemoteKeyedStateHandle (registered = {}) for checkpoint {} from backend with id {}.",
isRegistered,
checkpointId,
backendIdentifier);
try {
metaStateHandle.discardState();
} catch (Exception e) {
LOG.warn("Could not properly discard meta data.", e);
}
try {
StateUtil.bestEffortDiscardAllStateObjects(
privateState.stream()
.map(HandleAndLocalPath::getHandle)
.collect(Collectors.toList()));
} catch (Exception e) {
LOG.warn("Could not properly discard misc file states.", e);
}
// discard only on TM; on JM, shared state is removed on subsumption
if (!isRegistered) {
try {
StateUtil.bestEffortDiscardAllStateObjects(
sharedState.stream()
.map(HandleAndLocalPath::getHandle)
.collect(Collectors.toList()));
} catch (Exception e) {
LOG.warn("Could not properly discard new sst file states.", e);
}
}
}
@Override
public long getStateSize() {
long size = StateUtil.getStateSize(metaStateHandle);
for (HandleAndLocalPath handleAndLocalPath : sharedState) {
size += handleAndLocalPath.getStateSize();
}
for (HandleAndLocalPath handleAndLocalPath : privateState) {
size += handleAndLocalPath.getStateSize();
}
return size;
}
@Override
public long getCheckpointedSize() {
return persistedSizeOfThisCheckpoint;
}
@Override
public void registerSharedStates(SharedStateRegistry stateRegistry, long checkpointID) {
// 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 IncrementalRemoteKeyedStateHandle for checkpoint {} from backend with id {}.",
checkpointId,
backendIdentifier);
for (HandleAndLocalPath handleAndLocalPath : sharedState) {
StreamStateHandle reference =
stateRegistry.registerReference(
createSharedStateRegistryKey(handleAndLocalPath.getHandle()),
handleAndLocalPath.getHandle(),
checkpointID);
// This step consolidates our shared handles with the registry, which will replace
// placeholder state handle with already registered, actual state handles.
// Because of SharedStateRegistryKey is based on the physical id of the stream handle,
// no de-duplication will be performed. see FLINK-29913.
handleAndLocalPath.replaceHandle(reference);
}
}
@VisibleForTesting
IncrementalRemoteKeyedStateHandle copy() {
return new IncrementalRemoteKeyedStateHandle(
backendIdentifier,
keyGroupRange,
checkpointId,
sharedState,
privateState,
metaStateHandle,
persistedSizeOfThisCheckpoint,
stateHandleId);
}
/** Create a unique key based on physical id to register one of our shared state handles. */
@VisibleForTesting
public SharedStateRegistryKey createSharedStateRegistryKey(StreamStateHandle handle) {
String keyString = handle.getStreamStateHandleID().getKeyString();
// key strings tend to be longer, so we use the MD5 of the key string to save memory
return new SharedStateRegistryKey(
UUID.nameUUIDFromBytes(keyString.getBytes(StandardCharsets.UTF_8)).toString());
}
/**
* This method is should only be called in tests! This should never serve as key in a hash map.
*/
@VisibleForTesting
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
IncrementalRemoteKeyedStateHandle that = (IncrementalRemoteKeyedStateHandle) o;
if (!getStateHandleId().equals(that.getStateHandleId())) {
return false;
}
if (getCheckpointId() != that.getCheckpointId()) {
return false;
}
if (!getBackendIdentifier().equals(that.getBackendIdentifier())) {
return false;
}
if (!getKeyGroupRange().equals(that.getKeyGroupRange())) {
return false;
}
if (!getSharedState().equals(that.getSharedState())) {
return false;
}
if (!getPrivateState().equals(that.getPrivateState())) {
return false;
}
return getMetaStateHandle().equals(that.getMetaStateHandle());
}
/** This method should only be called in tests! This should never serve as key in a hash map. */
@VisibleForTesting
@Override
public int hashCode() {
int result = getBackendIdentifier().hashCode();
result = 31 * result + getKeyGroupRange().hashCode();
result = 31 * result + (int) (getCheckpointId() ^ (getCheckpointId() >>> 32));
result = 31 * result + getSharedState().hashCode();
result = 31 * result + getPrivateState().hashCode();
result = 31 * result + getMetaStateHandle().hashCode();
result = 31 * result + getStateHandleId().hashCode();
return result;
}
@Override
public String toString() {
return "IncrementalRemoteKeyedStateHandle{"
+ "backendIdentifier="
+ backendIdentifier
+ ", stateHandleId="
+ stateHandleId
+ ", keyGroupRange="
+ keyGroupRange
+ ", checkpointId="
+ checkpointId
+ ", sharedState="
+ sharedState
+ ", privateState="
+ privateState
+ ", metaStateHandle="
+ metaStateHandle
+ ", registered="
+ (sharedStateRegistry != null)
+ '}';
}
}