carp84 commented on a change in pull request #7674: [FLINK-10043] [State Backends] Refactor RocksDBKeyedStateBackend object construction/initialization/restore code URL: https://github.com/apache/flink/pull/7674#discussion_r257909986
########## File path: flink-state-backends/flink-statebackend-rocksdb/src/main/java/org/apache/flink/contrib/streaming/state/restore/RocksDBFullRestoreOperation.java ########## @@ -0,0 +1,276 @@ +/* + * 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.contrib.streaming.state.restore; + +import org.apache.flink.api.common.typeutils.TypeSerializerSchemaCompatibility; +import org.apache.flink.api.common.typeutils.base.array.BytePrimitiveArraySerializer; +import org.apache.flink.api.java.tuple.Tuple2; +import org.apache.flink.configuration.ConfigConstants; +import org.apache.flink.contrib.streaming.state.RocksDBKeyedStateBackend; +import org.apache.flink.contrib.streaming.state.RocksDBNativeMetricMonitor; +import org.apache.flink.contrib.streaming.state.RocksDBWriteBatchWrapper; +import org.apache.flink.contrib.streaming.state.StateColumnFamilyHandle; +import org.apache.flink.core.fs.CloseableRegistry; +import org.apache.flink.core.fs.FSDataInputStream; +import org.apache.flink.core.memory.DataInputView; +import org.apache.flink.core.memory.DataInputViewStreamWrapper; +import org.apache.flink.runtime.state.KeyGroupRange; +import org.apache.flink.runtime.state.KeyGroupsStateHandle; +import org.apache.flink.runtime.state.KeyedBackendSerializationProxy; +import org.apache.flink.runtime.state.KeyedStateHandle; +import org.apache.flink.runtime.state.RegisteredStateMetaInfoBase; +import org.apache.flink.runtime.state.SnappyStreamCompressionDecorator; +import org.apache.flink.runtime.state.StateSerializerProvider; +import org.apache.flink.runtime.state.StreamCompressionDecorator; +import org.apache.flink.runtime.state.UncompressedStreamCompressionDecorator; +import org.apache.flink.runtime.state.metainfo.StateMetaInfoSnapshot; +import org.apache.flink.util.IOUtils; +import org.apache.flink.util.Preconditions; +import org.apache.flink.util.StateMigrationException; + +import org.rocksdb.ColumnFamilyDescriptor; +import org.rocksdb.ColumnFamilyHandle; +import org.rocksdb.ColumnFamilyOptions; +import org.rocksdb.DBOptions; +import org.rocksdb.RocksDB; +import org.rocksdb.RocksDBException; + +import java.io.File; +import java.io.IOException; +import java.io.InputStream; +import java.util.ArrayList; +import java.util.Collection; +import java.util.List; +import java.util.Map; + +import static org.apache.flink.contrib.streaming.state.snapshot.RocksSnapshotUtil.END_OF_KEY_GROUP_MARK; +import static org.apache.flink.contrib.streaming.state.snapshot.RocksSnapshotUtil.clearMetaDataFollowsFlag; +import static org.apache.flink.contrib.streaming.state.snapshot.RocksSnapshotUtil.hasMetaDataFollowsFlag; + +/** + * Encapsulates the process of restoring a RocksDB instance from a full snapshot. + */ +public class RocksDBFullRestoreOperation<K> extends AbstractRocksDBRestoreOperation<K> { + /** + * Current key-groups state handle from which we restore key-groups. + */ + private KeyGroupsStateHandle currentKeyGroupsStateHandle; + /** + * Current input stream we obtained from currentKeyGroupsStateHandle. + */ + private FSDataInputStream currentStateHandleInStream; + /** + * Current data input view that wraps currentStateHandleInStream. + */ + private DataInputView currentStateHandleInView; + /** + * Current list of ColumnFamilyHandles for all column families we restore from currentKeyGroupsStateHandle. + */ + private List<ColumnFamilyHandle> currentStateHandleKVStateColumnFamilies; + /** + * The compression decorator that was used for writing the state, as determined by the meta data. + */ + private StreamCompressionDecorator keygroupStreamCompressionDecorator; + + private boolean isKeySerializerCompatibilityChecked; + + public RocksDBFullRestoreOperation(KeyGroupRange keyGroupRange, + int keyGroupPrefixBytes, + int numberOfTransferringThreads, + CloseableRegistry cancelStreamRegistry, + ClassLoader userCodeClassLoader, + Map<String, StateColumnFamilyHandle> kvStateInformation, + StateSerializerProvider<K> keySerializerProvider, + File instanceBasePath, + File instanceRocksDBPath, + DBOptions dbOptions, + ColumnFamilyOptions columnOptions, + RocksDBNativeMetricMonitor nativeMetricMonitor) { + super(keyGroupRange, + keyGroupPrefixBytes, + numberOfTransferringThreads, + cancelStreamRegistry, + userCodeClassLoader, + kvStateInformation, + keySerializerProvider, + instanceBasePath, + instanceRocksDBPath, + dbOptions, + columnOptions, + nativeMetricMonitor); + } + + /** + * Restores all key-groups data that is referenced by the passed state handles. + * @param keyedStateHandles List of all key groups state handles that shall be restored. + * @param db + */ + @Override + public RocksDBRestoreResult restore(Collection<KeyedStateHandle> keyedStateHandles, RocksDB db) + throws IOException, StateMigrationException, RocksDBException { + if (db == null) { + openDB(); + } else { + this.db = db; + } + for (KeyedStateHandle keyedStateHandle : keyedStateHandles) { + if (keyedStateHandle != null) { + + if (!(keyedStateHandle instanceof KeyGroupsStateHandle)) { + throw new IllegalStateException("Unexpected state handle type, " + + "expected: " + KeyGroupsStateHandle.class + + ", but found: " + keyedStateHandle.getClass()); + } + this.currentKeyGroupsStateHandle = (KeyGroupsStateHandle) keyedStateHandle; + restoreKeyGroupsInStateHandle(); + } + } + return new RocksDBRestoreResult(this.db, lastCompletedCheckpointId, backendUID, + restoredSstFiles, defaultColumnFamilyHandle); + } + + /** + * Restore one key groups state handle. + */ + private void restoreKeyGroupsInStateHandle() + throws IOException, StateMigrationException, RocksDBException { + try { + currentStateHandleInStream = currentKeyGroupsStateHandle.openInputStream(); + cancelStreamRegistry.registerCloseable(currentStateHandleInStream); + currentStateHandleInView = new DataInputViewStreamWrapper(currentStateHandleInStream); + restoreKVStateMetaData(); + restoreKVStateData(); + } finally { + if (cancelStreamRegistry.unregisterCloseable(currentStateHandleInStream)) { + IOUtils.closeQuietly(currentStateHandleInStream); + } + } + } + + /** + * Restore the KV-state / ColumnFamily meta data for all key-groups referenced by the current state handle. + */ + private void restoreKVStateMetaData() throws IOException, StateMigrationException, RocksDBException { + + // isSerializerPresenceRequired flag is set to false, since for the RocksDB state backend, + // deserialization of state happens lazily during runtime; we depend on the fact + // that the new serializer for states could be compatible, and therefore the restore can continue + // without old serializers required to be present. + KeyedBackendSerializationProxy<K> serializationProxy = + new KeyedBackendSerializationProxy<>(userCodeClassLoader); + + serializationProxy.read(currentStateHandleInView); + + if (!isKeySerializerCompatibilityChecked) { + // check for key serializer compatibility; this also reconfigures the + // key serializer to be compatible, if it is required and is possible + TypeSerializerSchemaCompatibility<K> keySerializerSchemaCompat = + keySerializerProvider.setPreviousSerializerSnapshotForRestoredState(serializationProxy.getKeySerializerSnapshot()); Review comment: Agreed but please allow me to leave this as the last task of this review round, after emptying `restore` of rocksdb backend and remove those many `if` to prevent double-restore. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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