/*
* 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 gobblin.source.extractor.extract.kafka.workunit.packer;
import java.util.List;
import java.util.Map;
import com.google.common.collect.Lists;
import com.google.common.math.DoubleMath;
import gobblin.configuration.SourceState;
import gobblin.source.extractor.extract.AbstractSource;
import gobblin.source.workunit.MultiWorkUnit;
import gobblin.source.workunit.WorkUnit;
/**
* An implementation of {@link KafkaWorkUnitPacker} with a single level of bin packing using worst-fit-decreasing.
*
* Note that for each skipped topic, an empty workunit is created for each partition to preserve its checkpoints.
* In single-level bin packing mode, it still assigns all partitions of a skipped topic to the same workunit / task,
* so that a single empty task will be created for this topic, instead of one empty task per partition.
*
* Please refer to the Javadoc of {@link KafkaBiLevelWorkUnitPacker} for a comparison between
* {@link KafkaSingleLevelWorkUnitPacker} and {@link KafkaBiLevelWorkUnitPacker}.
*
* @author Ziyang Liu
*/
public class KafkaSingleLevelWorkUnitPacker extends KafkaWorkUnitPacker {
protected KafkaSingleLevelWorkUnitPacker(AbstractSource<?, ?> source, SourceState state) {
super(source, state);
}
@Override
public List<WorkUnit> pack(Map<String, List<WorkUnit>> workUnitsByTopic, int numContainers) {
setWorkUnitEstSizes(workUnitsByTopic);
List<WorkUnit> workUnits = Lists.newArrayList();
for (List<WorkUnit> workUnitsForTopic : workUnitsByTopic.values()) {
// For each topic, merge all empty workunits into a single workunit, so that a single
// empty task will be created instead of many.
MultiWorkUnit zeroSizeWorkUnit = MultiWorkUnit.createEmpty();
for (WorkUnit workUnit : workUnitsForTopic) {
if (DoubleMath.fuzzyEquals(getWorkUnitEstSize(workUnit), 0.0, EPS)) {
addWorkUnitToMultiWorkUnit(workUnit, zeroSizeWorkUnit);
} else {
workUnit.setWatermarkInterval(getWatermarkIntervalFromWorkUnit(workUnit));
workUnits.add(workUnit);
}
}
if (!zeroSizeWorkUnit.getWorkUnits().isEmpty()) {
workUnits.add(squeezeMultiWorkUnit(zeroSizeWorkUnit));
}
}
return worstFitDecreasingBinPacking(workUnits, numContainers);
}
}