gustavodemorais commented on code in PR #26313: URL: https://github.com/apache/flink/pull/26313#discussion_r2106159198
########## flink-table/flink-table-runtime/src/main/java/org/apache/flink/table/runtime/operators/join/stream/state/MultiJoinStateViews.java: ########## @@ -0,0 +1,440 @@ +/* + * 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.table.runtime.operators.join.stream.state; + +import org.apache.flink.api.common.functions.RuntimeContext; +import org.apache.flink.api.common.state.MapState; +import org.apache.flink.api.common.state.MapStateDescriptor; +import org.apache.flink.api.common.state.StateTtlConfig; +import org.apache.flink.api.common.typeinfo.TypeInformation; +import org.apache.flink.api.common.typeinfo.Types; +import org.apache.flink.api.java.functions.KeySelector; +import org.apache.flink.table.data.GenericRowData; +import org.apache.flink.table.data.RowData; +import org.apache.flink.table.runtime.operators.join.stream.utils.JoinInputSideSpec; +import org.apache.flink.table.runtime.typeutils.InternalTypeInfo; +import org.apache.flink.table.types.logical.RowType; +import org.apache.flink.types.RowKind; +import org.apache.flink.util.IterableIterator; + +import java.util.ArrayList; +import java.util.Collections; +import java.util.Iterator; +import java.util.List; +import java.util.Map; +import java.util.NoSuchElementException; + +import static org.apache.flink.table.runtime.util.StateConfigUtil.createTtlConfig; +import static org.apache.flink.util.Preconditions.checkNotNull; + +/** + * Factory class to create different implementations of {@link MultiJoinStateView} based on the + * characteristics described in {@link JoinInputSideSpec}. + * + * <p>Each state view uses a {@link MapState} where the primary key is the `joinKey` derived from + * the join conditions (via {@link + * org.apache.flink.table.runtime.operators.join.stream.keyselector.JoinKeyExtractor}). The value + * stored within this map depends on whether the input side has a unique key and how it relates to + * the join key, optimizing storage and access patterns. + */ +public final class MultiJoinStateViews { + + /** Creates a {@link MultiJoinStateView} depends on {@link JoinInputSideSpec}. */ + public static MultiJoinStateView create( + RuntimeContext ctx, + String stateName, + JoinInputSideSpec inputSideSpec, + InternalTypeInfo<RowData> joinKeyType, // Type info for the outer map key + InternalTypeInfo<RowData> recordType, + long retentionTime) { + StateTtlConfig ttlConfig = createTtlConfig(retentionTime); + + if (inputSideSpec.hasUniqueKey()) { + if (inputSideSpec.joinKeyContainsUniqueKey()) { + return new JoinKeyContainsUniqueKey( + ctx, stateName, joinKeyType, recordType, ttlConfig); + } else { + return new InputSideHasUniqueKey( + ctx, + stateName, + joinKeyType, + recordType, + inputSideSpec.getUniqueKeyType(), + inputSideSpec.getUniqueKeySelector(), + ttlConfig); + } + } else { + return new InputSideHasNoUniqueKey(ctx, stateName, joinKeyType, recordType, ttlConfig); + } + } + + /** + * Creates a {@link MapStateDescriptor} with the given parameters and applies TTL configuration. + * + * @param <K> Key type + * @param <V> Value type + * @param stateName Unique name for the state + * @param keyTypeInfo Type information for the key + * @param valueTypeInfo Type information for the value + * @param ttlConfig State TTL configuration + * @return Configured MapStateDescriptor + */ + private static <K, V> MapStateDescriptor<K, V> createStateDescriptor( + String stateName, + TypeInformation<K> keyTypeInfo, + TypeInformation<V> valueTypeInfo, + StateTtlConfig ttlConfig) { + MapStateDescriptor<K, V> descriptor = + new MapStateDescriptor<>(stateName, keyTypeInfo, valueTypeInfo); + if (ttlConfig.isEnabled()) { + descriptor.enableTimeToLive(ttlConfig); + } + return descriptor; + } + + // ------------------------------------------------------------------------------------ + // Multi Join State View Implementations + // ------------------------------------------------------------------------------------ + + /** + * State view for input sides where the unique key is fully contained within the join key. + * + * <p>Stores data as {@code MapState<JoinKey, Record>}. + */ + private static final class JoinKeyContainsUniqueKey implements MultiJoinStateView { + + // stores record in the mapping <JoinKey, Record> + private final MapState<RowData, RowData> recordState; + private final List<RowData> reusedList; + + private JoinKeyContainsUniqueKey( + RuntimeContext ctx, + final String stateName, + final InternalTypeInfo<RowData> joinKeyType, + final InternalTypeInfo<RowData> recordType, + final StateTtlConfig ttlConfig) { + + MapStateDescriptor<RowData, RowData> recordStateDesc = + createStateDescriptor(stateName, joinKeyType, recordType, ttlConfig); + + this.recordState = ctx.getMapState(recordStateDesc); + // the result records always not more than 1 per joinKey + this.reusedList = new ArrayList<>(1); + } + + @Override + public void addRecord(RowData joinKey, RowData record) throws Exception { + recordState.put(joinKey, record); + } + + @Override + public void retractRecord(RowData joinKey, RowData record) throws Exception { + recordState.remove(joinKey); + } + + @Override + public Iterable<RowData> getRecords(RowData joinKey) throws Exception { + reusedList.clear(); + RowData record = recordState.get(joinKey); + if (record != null) { + reusedList.add(record); + } + return reusedList; + } + + @Override + public void cleanup(RowData joinKey) throws Exception { + recordState.remove(joinKey); + } + } + + /** + * State view for input sides that have a unique key, but it differs from the join key. + * + * <p>Stores data as {@code MapState<CompositeKey<JoinKey, UK>, Record>}. The composite key is a + * RowData with 2 fields: joinKey and uniqueKey. + */ + private static final class InputSideHasUniqueKey implements MultiJoinStateView { + + // stores record in the mapping <(JoinKey, UK), Record> + private final MapState<RowData, RowData> recordState; + private final KeySelector<RowData, RowData> uniqueKeySelector; + private final InternalTypeInfo<RowData> joinKeyType; + + private InputSideHasUniqueKey( + RuntimeContext ctx, + final String stateName, + final InternalTypeInfo<RowData> joinKeyType, + final InternalTypeInfo<RowData> recordType, + final InternalTypeInfo<RowData> uniqueKeyType, + final KeySelector<RowData, RowData> uniqueKeySelector, + final StateTtlConfig ttlConfig) { + checkNotNull(uniqueKeyType); + checkNotNull(uniqueKeySelector); + this.uniqueKeySelector = uniqueKeySelector; + this.joinKeyType = joinKeyType; + + // Composite key type: RowData with 2 fields (joinKey, uniqueKey) + // The composite key is a RowData with joinKey at index 0 and uniqueKey at index 1. + // TODO Gustavo: there is probably a cleaner way of instantiating the type + final RowType keyRowType = + RowType.of(joinKeyType.toRowType(), uniqueKeyType.toRowType()); + InternalTypeInfo<RowData> compositeKeyType = InternalTypeInfo.of(keyRowType); + + MapStateDescriptor<RowData, RowData> recordStateDesc = + createStateDescriptor(stateName, compositeKeyType, recordType, ttlConfig); + + this.recordState = ctx.getMapState(recordStateDesc); + } + + private RowData createCompositeKey(RowData joinKey, RowData uniqueKey) { + GenericRowData compositeKey = new GenericRowData(2); + compositeKey.setField(0, joinKey); + compositeKey.setField(1, uniqueKey); + return compositeKey; + } + + @Override + public void addRecord(RowData joinKey, RowData record) throws Exception { + RowData uniqueKey = uniqueKeySelector.getKey(record); + RowData compositeKey = createCompositeKey(joinKey, uniqueKey); + recordState.put(compositeKey, record); + } + + @Override + public void retractRecord(RowData joinKey, RowData record) throws Exception { + RowData uniqueKey = uniqueKeySelector.getKey(record); + RowData compositeKey = createCompositeKey(joinKey, uniqueKey); + recordState.remove(compositeKey); + } + + @Override + public Iterable<RowData> getRecords(RowData joinKey) throws Exception { + Iterator<Map.Entry<RowData, RowData>> stateIterator = recordState.iterator(); + if (stateIterator == null) { + return Collections.emptyList(); + } + + // Consume the record + // This iterator is stateful and intended for single use per call to getRecords. + //noinspection NullableProblems TODO Gustavo can we not supress? + return new IterableIterator<>() { + private RowData nextRecord = null; + + @Override + public boolean hasNext() { + if (nextRecord != null) { + return true; + } + while (stateIterator.hasNext()) { + Map.Entry<RowData, RowData> entry = stateIterator.next(); + RowData compositeKey = entry.getKey(); + RowData currentJoinKey = compositeKey.getRow(0, joinKeyType.getArity()); + if (joinKey.equals(currentJoinKey)) { + nextRecord = entry.getValue(); + return true; + } + } + return false; Review Comment: > I'm pretty sure that this optimization would be required, but I still might be wrong :) How could we implement this RocksDB-optimized version - is this an operator decision? If you have any pointers to where we do something similar, would be happy to look into those. > It would be great to add a benchmark to https://github.com/apache/flink-benchmarks Yes, there are multiple smaller optimizations that I have in my todo list to try out but wanted to do them only after I'm able to measure things. Basically following one of the "general remarks" from the benchmarks repo "If you can not measure the performance difference, then just don't bother (avoid premature optimisations)" -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
