org.apache.flink.runtime.jobmaster.slotpool.PreviousAllocationSchedulingStrategy Maven / Gradle / Ivy
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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
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*/
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 org.apache.flink.runtime.jobmaster.SlotContext;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.util.Collection;
import java.util.function.BiFunction;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.stream.Stream;
/**
* {@link SchedulingStrategy} which tries to match a slot with its previous {@link AllocationID}.
* If the previous allocation cannot be found, then it returns {@code null}. If the slot has not
* been scheduled before (no assigned allocation id), it will fall back to
* {@link LocationPreferenceSchedulingStrategy}.
*/
public class PreviousAllocationSchedulingStrategy extends LocationPreferenceSchedulingStrategy {
private static final PreviousAllocationSchedulingStrategy INSTANCE = new PreviousAllocationSchedulingStrategy();
private PreviousAllocationSchedulingStrategy() {}
@Nullable
@Override
public OUT findMatchWithLocality(
@Nonnull SlotProfile slotProfile,
@Nonnull Stream candidates,
@Nonnull Function contextExtractor,
@Nonnull Predicate additionalRequirementsFilter,
@Nonnull BiFunction resultProducer) {
Collection priorAllocations = slotProfile.getPriorAllocations();
if (priorAllocations.isEmpty()) {
return super.findMatchWithLocality(slotProfile, candidates, contextExtractor, additionalRequirementsFilter, resultProducer);
} else {
return findPreviousAllocation(candidates, contextExtractor, additionalRequirementsFilter, resultProducer, priorAllocations);
}
}
@Nullable
private OUT findPreviousAllocation(
@Nonnull Stream candidates,
@Nonnull Function contextExtractor,
@Nonnull Predicate additionalRequirementsFilter,
@Nonnull BiFunction resultProducer,
Collection priorAllocations) {
Predicate filterByAllocation =
(candidate) -> priorAllocations.contains(contextExtractor.apply(candidate).getAllocationId());
return candidates
.filter(filterByAllocation.and(additionalRequirementsFilter))
.findFirst()
.map((result) -> resultProducer.apply(result, Locality.LOCAL)) // TODO introduce special locality?
.orElse(null);
}
public static PreviousAllocationSchedulingStrategy getInstance() {
return INSTANCE;
}
}