pvary commented on code in PR #10457: URL: https://github.com/apache/iceberg/pull/10457#discussion_r1642704253
########## flink/v1.19/flink/src/main/java/org/apache/iceberg/flink/sink/shuffle/RangePartitioner.java: ########## @@ -0,0 +1,110 @@ +/* + * 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 java.util.Random; +import java.util.concurrent.atomic.AtomicLong; +import org.apache.flink.annotation.Internal; +import org.apache.flink.api.common.functions.Partitioner; +import org.apache.flink.table.data.RowData; +import org.apache.iceberg.Schema; +import org.apache.iceberg.SortOrder; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** The wrapper class */ +@Internal +public class RangePartitioner implements Partitioner<StatisticsOrRecord> { + private static final Logger LOG = LoggerFactory.getLogger(RangePartitioner.class); + + private final Schema schema; + private final SortOrder sortOrder; + + private transient AtomicLong roundRobinCounter; + private transient Partitioner<RowData> delegatePartitioner; + + public RangePartitioner(Schema schema, SortOrder sortOrder) { + this.schema = schema; + this.sortOrder = sortOrder; + } + + @Override + public int partition(StatisticsOrRecord wrapper, int numPartitions) { + if (wrapper.hasStatistics()) { + this.delegatePartitioner = delegatePartitioner(wrapper.statistics()); + return (int) (roundRobinCounter(numPartitions).getAndIncrement() % numPartitions); + } else { + if (delegatePartitioner != null) { + return delegatePartitioner.partition(wrapper.record(), numPartitions); + } else { + int partition = (int) (roundRobinCounter(numPartitions).getAndIncrement() % numPartitions); + LOG.trace("Statistics not available. Round robin to partition {}", partition); + return partition; + } + } + } + + private AtomicLong roundRobinCounter(int numPartitions) { + if (roundRobinCounter == null) { + // randomize the starting point to avoid synchronization across subtasks + this.roundRobinCounter = new AtomicLong(new Random().nextInt(numPartitions)); + } + + return roundRobinCounter; + } + + private Partitioner<RowData> delegatePartitioner(GlobalStatistics statistics) { + if (statistics.type() == StatisticsType.Map) { + return new MapRangePartitioner(schema, sortOrder, statistics.mapAssignment()); + } else if (statistics.type() == StatisticsType.Sketch) { + return new SketchRangePartitioner(schema, sortOrder, statistics.rangeBounds()); + } else { + throw new IllegalArgumentException( + String.format("Invalid statistics type: %s. Should be Map or Sketch", statistics.type())); + } + } Review Comment: I still struggling a bit creating a good mental model for the `GlobalStatistics` distribution. I feel that separating out the `GlobalStatistics` would be good if we could create a data structure which could be used by both `MapRangePartitioner` and `SketchRangePartitioner`, but sadly these partitioners require different input data. Would it make sense to serialize/parametrize the partitioner on the JM side and send it in the records instead of the `GlobalStatistics` in the `StatisticsOrRecord`? Like `PartitionerOrRecord`, and on the partitioner side we just call the `partition` and forget it. Would this be easier to understand for others? -- 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
