forked from apache/flink
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
[FLINK-21151] Move asynchronous writing part out of RocksDB strategy
The previous preparations allow us to put this backend-independent part into flink-runtime, where it can be used by other backends to write snapshots in the same common format. FullSnapshotResources is now the common thing that backends must provide.
- Loading branch information
Showing
7 changed files
with
347 additions
and
238 deletions.
There are no files selected for viewing
233 changes: 233 additions & 0 deletions
233
flink-runtime/src/main/java/org/apache/flink/runtime/state/FullSnapshotAsyncWriter.java
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,233 @@ | ||
| /* | ||
| * 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.api.common.typeutils.base.array.BytePrimitiveArraySerializer; | ||
| import org.apache.flink.core.fs.CloseableRegistry; | ||
| import org.apache.flink.core.memory.DataOutputView; | ||
| import org.apache.flink.core.memory.DataOutputViewStreamWrapper; | ||
| import org.apache.flink.util.IOUtils; | ||
| import org.apache.flink.util.function.SupplierWithException; | ||
|
|
||
| import javax.annotation.Nonnull; | ||
|
|
||
| import java.io.IOException; | ||
| import java.io.OutputStream; | ||
| import java.util.Objects; | ||
|
|
||
| import static org.apache.flink.runtime.state.FullSnapshotUtil.END_OF_KEY_GROUP_MARK; | ||
| import static org.apache.flink.runtime.state.FullSnapshotUtil.hasMetaDataFollowsFlag; | ||
| import static org.apache.flink.runtime.state.FullSnapshotUtil.setMetaDataFollowsFlagInKey; | ||
|
|
||
| /** | ||
| * An asynchronous writer that can write a full snapshot/savepoint from a {@link | ||
| * FullSnapshotResources}. | ||
| * | ||
| * @param <K> type of the backend keys. | ||
| */ | ||
| public class FullSnapshotAsyncWriter<K> | ||
| implements SnapshotStrategy.SnapshotResultSupplier<KeyedStateHandle> { | ||
|
|
||
| /** Supplier for the stream into which we write the snapshot. */ | ||
| @Nonnull | ||
| private final SupplierWithException<CheckpointStreamWithResultProvider, Exception> | ||
| checkpointStreamSupplier; | ||
|
|
||
| @Nonnull private final FullSnapshotResources<K> snapshotResources; | ||
|
|
||
| public FullSnapshotAsyncWriter( | ||
| @Nonnull | ||
| SupplierWithException<CheckpointStreamWithResultProvider, Exception> | ||
| checkpointStreamSupplier, | ||
| @Nonnull FullSnapshotResources<K> snapshotResources) { | ||
|
|
||
| this.checkpointStreamSupplier = checkpointStreamSupplier; | ||
| this.snapshotResources = snapshotResources; | ||
| } | ||
|
|
||
| @Override | ||
| public SnapshotResult<KeyedStateHandle> get(CloseableRegistry snapshotCloseableRegistry) | ||
| throws Exception { | ||
| final KeyGroupRangeOffsets keyGroupRangeOffsets = | ||
| new KeyGroupRangeOffsets(snapshotResources.getKeyGroupRange()); | ||
| final CheckpointStreamWithResultProvider checkpointStreamWithResultProvider = | ||
| checkpointStreamSupplier.get(); | ||
|
|
||
| snapshotCloseableRegistry.registerCloseable(checkpointStreamWithResultProvider); | ||
| writeSnapshotToOutputStream(checkpointStreamWithResultProvider, keyGroupRangeOffsets); | ||
|
|
||
| if (snapshotCloseableRegistry.unregisterCloseable(checkpointStreamWithResultProvider)) { | ||
| return CheckpointStreamWithResultProvider.toKeyedStateHandleSnapshotResult( | ||
| checkpointStreamWithResultProvider.closeAndFinalizeCheckpointStreamResult(), | ||
| keyGroupRangeOffsets); | ||
| } else { | ||
| throw new IOException("Stream is already unregistered/closed."); | ||
| } | ||
| } | ||
|
|
||
| private void writeSnapshotToOutputStream( | ||
| @Nonnull CheckpointStreamWithResultProvider checkpointStreamWithResultProvider, | ||
| @Nonnull KeyGroupRangeOffsets keyGroupRangeOffsets) | ||
| throws IOException, InterruptedException { | ||
|
|
||
| final DataOutputView outputView = | ||
| new DataOutputViewStreamWrapper( | ||
| checkpointStreamWithResultProvider.getCheckpointOutputStream()); | ||
|
|
||
| writeKVStateMetaData(outputView); | ||
|
|
||
| try (KeyValueStateIterator kvStateIterator = snapshotResources.createKVStateIterator()) { | ||
| writeKVStateData( | ||
| kvStateIterator, checkpointStreamWithResultProvider, keyGroupRangeOffsets); | ||
| } | ||
| } | ||
|
|
||
| private void writeKVStateMetaData(final DataOutputView outputView) throws IOException { | ||
|
|
||
| KeyedBackendSerializationProxy<K> serializationProxy = | ||
| new KeyedBackendSerializationProxy<>( | ||
| // TODO: this code assumes that writing a serializer is threadsafe, we | ||
| // should support to | ||
| // get a serialized form already at state registration time in the | ||
| // future | ||
| snapshotResources.getKeySerializer(), | ||
| snapshotResources.getMetaInfoSnapshots(), | ||
| !Objects.equals( | ||
| UncompressedStreamCompressionDecorator.INSTANCE, | ||
| snapshotResources.getStreamCompressionDecorator())); | ||
|
|
||
| serializationProxy.write(outputView); | ||
| } | ||
|
|
||
| private void writeKVStateData( | ||
| final KeyValueStateIterator mergeIterator, | ||
| final CheckpointStreamWithResultProvider checkpointStreamWithResultProvider, | ||
| final KeyGroupRangeOffsets keyGroupRangeOffsets) | ||
| throws IOException, InterruptedException { | ||
|
|
||
| byte[] previousKey = null; | ||
| byte[] previousValue = null; | ||
| DataOutputView kgOutView = null; | ||
| OutputStream kgOutStream = null; | ||
| CheckpointStreamFactory.CheckpointStateOutputStream checkpointOutputStream = | ||
| checkpointStreamWithResultProvider.getCheckpointOutputStream(); | ||
|
|
||
| try { | ||
|
|
||
| // preamble: setup with first key-group as our lookahead | ||
| if (mergeIterator.isValid()) { | ||
| // begin first key-group by recording the offset | ||
| keyGroupRangeOffsets.setKeyGroupOffset( | ||
| mergeIterator.keyGroup(), checkpointOutputStream.getPos()); | ||
| // write the k/v-state id as metadata | ||
| kgOutStream = | ||
| snapshotResources | ||
| .getStreamCompressionDecorator() | ||
| .decorateWithCompression(checkpointOutputStream); | ||
| kgOutView = new DataOutputViewStreamWrapper(kgOutStream); | ||
| // TODO this could be aware of keyGroupPrefixBytes and write only one byte | ||
| // if possible | ||
| kgOutView.writeShort(mergeIterator.kvStateId()); | ||
| previousKey = mergeIterator.key(); | ||
| previousValue = mergeIterator.value(); | ||
| mergeIterator.next(); | ||
| } | ||
|
|
||
| // main loop: write k/v pairs ordered by (key-group, kv-state), thereby tracking | ||
| // key-group offsets. | ||
| while (mergeIterator.isValid()) { | ||
|
|
||
| assert (!hasMetaDataFollowsFlag(previousKey)); | ||
|
|
||
| // set signal in first key byte that meta data will follow in the stream | ||
| // after this k/v pair | ||
| if (mergeIterator.isNewKeyGroup() || mergeIterator.isNewKeyValueState()) { | ||
|
|
||
| // be cooperative and check for interruption from time to time in the | ||
| // hot loop | ||
| checkInterrupted(); | ||
|
|
||
| setMetaDataFollowsFlagInKey(previousKey); | ||
| } | ||
|
|
||
| writeKeyValuePair(previousKey, previousValue, kgOutView); | ||
|
|
||
| // write meta data if we have to | ||
| if (mergeIterator.isNewKeyGroup()) { | ||
| // TODO this could be aware of keyGroupPrefixBytes and write only one | ||
| // byte if possible | ||
| kgOutView.writeShort(END_OF_KEY_GROUP_MARK); | ||
| // this will just close the outer stream | ||
| kgOutStream.close(); | ||
| // begin new key-group | ||
| keyGroupRangeOffsets.setKeyGroupOffset( | ||
| mergeIterator.keyGroup(), checkpointOutputStream.getPos()); | ||
| // write the kev-state | ||
| // TODO this could be aware of keyGroupPrefixBytes and write only one | ||
| // byte if possible | ||
| kgOutStream = | ||
| snapshotResources | ||
| .getStreamCompressionDecorator() | ||
| .decorateWithCompression(checkpointOutputStream); | ||
| kgOutView = new DataOutputViewStreamWrapper(kgOutStream); | ||
| kgOutView.writeShort(mergeIterator.kvStateId()); | ||
| } else if (mergeIterator.isNewKeyValueState()) { | ||
| // write the k/v-state | ||
| // TODO this could be aware of keyGroupPrefixBytes and write only one | ||
| // byte if possible | ||
| kgOutView.writeShort(mergeIterator.kvStateId()); | ||
| } | ||
|
|
||
| // request next k/v pair | ||
| previousKey = mergeIterator.key(); | ||
| previousValue = mergeIterator.value(); | ||
| mergeIterator.next(); | ||
| } | ||
|
|
||
| // epilogue: write last key-group | ||
| if (previousKey != null) { | ||
| assert (!hasMetaDataFollowsFlag(previousKey)); | ||
| setMetaDataFollowsFlagInKey(previousKey); | ||
| writeKeyValuePair(previousKey, previousValue, kgOutView); | ||
| // TODO this could be aware of keyGroupPrefixBytes and write only one byte if | ||
| // possible | ||
| kgOutView.writeShort(END_OF_KEY_GROUP_MARK); | ||
| // this will just close the outer stream | ||
| kgOutStream.close(); | ||
| kgOutStream = null; | ||
| } | ||
|
|
||
| } finally { | ||
| // this will just close the outer stream | ||
| IOUtils.closeQuietly(kgOutStream); | ||
| } | ||
| } | ||
|
|
||
| private void writeKeyValuePair(byte[] key, byte[] value, DataOutputView out) | ||
| throws IOException { | ||
| BytePrimitiveArraySerializer.INSTANCE.serialize(key, out); | ||
| BytePrimitiveArraySerializer.INSTANCE.serialize(value, out); | ||
| } | ||
|
|
||
| private void checkInterrupted() throws InterruptedException { | ||
| if (Thread.currentThread().isInterrupted()) { | ||
| throw new InterruptedException("RocksDB snapshot interrupted."); | ||
| } | ||
| } | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
46 changes: 46 additions & 0 deletions
46
flink-runtime/src/main/java/org/apache/flink/runtime/state/FullSnapshotUtil.java
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,46 @@ | ||
| /* | ||
| * 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; | ||
|
|
||
| /** | ||
| * Utility methods and constants around creating and restoring full snapshots using {@link | ||
| * FullSnapshotAsyncWriter}. | ||
| */ | ||
| public class FullSnapshotUtil { | ||
|
|
||
| public static final int FIRST_BIT_IN_BYTE_MASK = 0x80; | ||
|
|
||
| public static final int END_OF_KEY_GROUP_MARK = 0xFFFF; | ||
|
|
||
| public static void setMetaDataFollowsFlagInKey(byte[] key) { | ||
| key[0] |= FIRST_BIT_IN_BYTE_MASK; | ||
| } | ||
|
|
||
| public static void clearMetaDataFollowsFlag(byte[] key) { | ||
| key[0] &= (~FIRST_BIT_IN_BYTE_MASK); | ||
| } | ||
|
|
||
| public static boolean hasMetaDataFollowsFlag(byte[] key) { | ||
| return 0 != (key[0] & FIRST_BIT_IN_BYTE_MASK); | ||
| } | ||
|
|
||
| private FullSnapshotUtil() { | ||
| throw new AssertionError(); | ||
| } | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.