org.apache.flink.runtime.resourcemanager.slotmanager.LeastUtilizationSlotMatchingStrategy Maven / Gradle / Ivy
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* distributed with this work for additional information
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* 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,
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* See the License for the specific language governing permissions and
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*/
package org.apache.flink.runtime.resourcemanager.slotmanager;
import org.apache.flink.runtime.clusterframework.types.ResourceProfile;
import org.apache.flink.runtime.instance.InstanceID;
import org.apache.flink.util.Preconditions;
import java.util.Collection;
import java.util.Comparator;
import java.util.Map;
import java.util.Optional;
import java.util.function.Function;
import java.util.stream.Collectors;
/**
* {@link SlotMatchingStrategy} which picks a matching slot from a TaskExecutor
* with the least utilization.
*/
public enum LeastUtilizationSlotMatchingStrategy implements SlotMatchingStrategy {
INSTANCE;
@Override
public Optional findMatchingSlot(
ResourceProfile requestedProfile,
Collection freeSlots,
Function numberRegisteredSlotsLookup) {
final Map numSlotsPerTaskExecutor = freeSlots.stream()
.collect(Collectors.groupingBy(
TaskManagerSlotInformation::getInstanceId,
Collectors.reducing(0, i -> 1, Integer::sum)));
return freeSlots.stream()
.filter(taskManagerSlot -> taskManagerSlot.isMatchingRequirement(requestedProfile))
.min(Comparator.comparingDouble(taskManagerSlot -> calculateUtilization(taskManagerSlot.getInstanceId(), numberRegisteredSlotsLookup, numSlotsPerTaskExecutor)));
}
private static double calculateUtilization(InstanceID instanceId, Function numberRegisteredSlotsLookup, Map numSlotsPerTaskExecutor) {
final int numberRegisteredSlots = numberRegisteredSlotsLookup.apply(instanceId);
Preconditions.checkArgument(numberRegisteredSlots > 0, "The TaskExecutor %s has no slots registered.", instanceId);
final int numberFreeSlots = numSlotsPerTaskExecutor.getOrDefault(instanceId, 0);
Preconditions.checkArgument(numberRegisteredSlots >= numberFreeSlots, "The TaskExecutor %s has fewer registered slots than free slots.", instanceId);
return (double) (numberRegisteredSlots - numberFreeSlots) / numberRegisteredSlots;
}
}