org.apache.flink.runtime.jobmaster.slotpool.PreviousAllocationSlotSelectionStrategy 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
* limitations under the License.
*/
package org.apache.flink.runtime.jobmaster.slotpool;
import org.apache.flink.runtime.clusterframework.types.AllocationID;
import org.apache.flink.runtime.clusterframework.types.SlotProfile;
import org.apache.flink.runtime.jobmanager.scheduler.Locality;
import javax.annotation.Nonnull;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Optional;
import java.util.Set;
/**
* This class implements a {@link SlotSelectionStrategy} that is based on previous allocations and
* falls back to using location preference hints if there is no previous allocation.
*/
public class PreviousAllocationSlotSelectionStrategy implements SlotSelectionStrategy {
private final SlotSelectionStrategy fallbackSlotSelectionStrategy;
private PreviousAllocationSlotSelectionStrategy(SlotSelectionStrategy fallbackSlotSelectionStrategy) {
this.fallbackSlotSelectionStrategy = fallbackSlotSelectionStrategy;
}
@Override
public Optional selectBestSlotForProfile(
@Nonnull Collection availableSlots,
@Nonnull SlotProfile slotProfile) {
Collection priorAllocations = slotProfile.getPreferredAllocations();
// First, if there was a prior allocation try to schedule to the same/old slot
if (!priorAllocations.isEmpty()) {
for (SlotInfoAndResources availableSlot : availableSlots) {
if (priorAllocations.contains(availableSlot.getSlotInfo().getAllocationId())) {
return Optional.of(
SlotInfoAndLocality.of(availableSlot.getSlotInfo(), Locality.LOCAL));
}
}
}
// Second, select based on location preference, excluding blacklisted allocations
Set blackListedAllocations = slotProfile.getPreviousExecutionGraphAllocations();
Collection availableAndAllowedSlots = computeWithoutBlacklistedSlots(availableSlots, blackListedAllocations);
return fallbackSlotSelectionStrategy.selectBestSlotForProfile(availableAndAllowedSlots, slotProfile);
}
@Nonnull
private Collection computeWithoutBlacklistedSlots(
@Nonnull Collection availableSlots,
@Nonnull Set blacklistedAllocations) {
if (blacklistedAllocations.isEmpty()) {
return Collections.unmodifiableCollection(availableSlots);
}
ArrayList availableAndAllowedSlots = new ArrayList<>(availableSlots.size());
for (SlotInfoAndResources availableSlot : availableSlots) {
if (!blacklistedAllocations.contains(availableSlot.getSlotInfo().getAllocationId())) {
availableAndAllowedSlots.add(availableSlot);
}
}
return availableAndAllowedSlots;
}
public static PreviousAllocationSlotSelectionStrategy create() {
return create(LocationPreferenceSlotSelectionStrategy.createDefault());
}
public static PreviousAllocationSlotSelectionStrategy create(SlotSelectionStrategy fallbackSlotSelectionStrategy) {
return new PreviousAllocationSlotSelectionStrategy(fallbackSlotSelectionStrategy);
}
}