pvary commented on code in PR #6382: URL: https://github.com/apache/iceberg/pull/6382#discussion_r1064211920
########## flink/v1.16/flink/src/main/java/org/apache/iceberg/flink/sink/shuffle/ShuffleOperator.java: ########## @@ -0,0 +1,132 @@ +/* + * 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.iceberg.flink.sink.shuffle; + +import org.apache.flink.api.common.state.ListState; +import org.apache.flink.api.common.state.ListStateDescriptor; +import org.apache.flink.api.common.typeinfo.TypeHint; +import org.apache.flink.api.common.typeinfo.TypeInformation; +import org.apache.flink.api.java.functions.KeySelector; +import org.apache.flink.runtime.operators.coordination.OperatorEvent; +import org.apache.flink.runtime.operators.coordination.OperatorEventGateway; +import org.apache.flink.runtime.operators.coordination.OperatorEventHandler; +import org.apache.flink.runtime.state.StateInitializationContext; +import org.apache.flink.runtime.state.StateSnapshotContext; +import org.apache.flink.streaming.api.operators.AbstractStreamOperator; +import org.apache.flink.streaming.api.operators.OneInputStreamOperator; +import org.apache.flink.streaming.runtime.streamrecord.StreamRecord; +import org.apache.iceberg.relocated.com.google.common.annotations.VisibleForTesting; + +/** + * Shuffle operator can help to improve data clustering based on the key. + * + * <p>It collects the data statistics information, sends to coordinator and gets the global data + * distribution weight from coordinator. Then it will ingest the weight into data stream(wrap by a + * class{@link ShuffleRecordWrapper}) and send to partitioner. + */ +class ShuffleOperator<T, K> extends AbstractStreamOperator<ShuffleRecordWrapper<T, K>> + implements OneInputStreamOperator<T, ShuffleRecordWrapper<T, K>>, OperatorEventHandler { + + private static final long serialVersionUID = 1L; + + private final KeySelector<T, K> keySelector; + private final OperatorEventGateway operatorEventGateway; + // key is generated by applying KeySelector to record + // value is the times key occurs + // TODO: support to store statistics for high cardinality cases + private transient DataStatistics<K> localDataStatistics; + private transient DataStatistics<K> globalDataStatistics; + private transient ListState<DataStatistics<K>> globalDataStatisticsState; + private transient DataStatisticsFactory<K> dataStatisticsFactory; + + public ShuffleOperator( + KeySelector<T, K> keySelector, + OperatorEventGateway operatorEventGateway, + DataStatisticsFactory<K> dataStatisticsFactory) { + this.keySelector = keySelector; + this.operatorEventGateway = operatorEventGateway; + this.dataStatisticsFactory = dataStatisticsFactory; + } + + @VisibleForTesting + ListStateDescriptor<DataStatistics<K>> generateGlobalDataDistributionWeightDescriptor() { + return new ListStateDescriptor<>( + "globalDataStatisticsState", TypeInformation.of(new TypeHint<DataStatistics<K>>() {})); + } + + @Override + public void initializeState(StateInitializationContext context) throws Exception { + localDataStatistics = dataStatisticsFactory.createDataStatistics(); + globalDataStatisticsState = + context + .getOperatorStateStore() + .getListState(generateGlobalDataDistributionWeightDescriptor()); + + if (globalDataStatisticsState.get() != null + && globalDataStatisticsState.get().iterator().hasNext()) { + globalDataStatistics = globalDataStatisticsState.get().iterator().next(); + } else { + globalDataStatistics = dataStatisticsFactory.createDataStatistics(); + } + } + + @Override + public void open() throws Exception { + // TODO: handle scaling up + if (globalDataStatistics != null && globalDataStatistics.size() > 0) { + output.collect(new StreamRecord<>(ShuffleRecordWrapper.fromStatistics(globalDataStatistics))); + } + } + + @Override + public void handleOperatorEvent(OperatorEvent evt) { + // TODO: receive event with globalDataDistributionWeight from coordinator and update + // globalDataStatistics + } + + @Override + public void processElement(StreamRecord<T> streamRecord) throws Exception { + final K key = keySelector.getKey(streamRecord.getValue()); + localDataStatistics.put(key); + output.collect(new StreamRecord<>(ShuffleRecordWrapper.fromRecord(streamRecord.getValue()))); + } + + @Override + public void snapshotState(StateSnapshotContext context) throws Exception { + long checkpointId = context.getCheckpointId(); + LOG.debug("Taking shuffle operator snapshot for checkpoint {}", checkpointId); + + // Set the globalDataDistributionWeightState state to the latest global value. + if (globalDataStatistics != null && globalDataStatistics.size() > 0) { + globalDataStatisticsState.clear(); + globalDataStatisticsState.add(globalDataStatistics); + } + + // TODO: send to coordinator + // For now we make it simple to send globalDataStatisticsState at checkpoint + + // Reset the local data count + localDataStatistics = dataStatisticsFactory.createDataStatistics(); Review Comment: Either `reset` or `clear` method - or a factory for the `DataStatistics`. TDigest does not have a `reset` or `clear` like method, but we can hide it if we want to use it later. I think we should decide what creates a cleaner API. -- 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...@iceberg.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@iceberg.apache.org For additional commands, e-mail: issues-h...@iceberg.apache.org
