azagrebin commented on a change in pull request #13071: URL: https://github.com/apache/flink/pull/13071#discussion_r466507859
########## File path: flink-runtime/src/main/java/org/apache/flink/runtime/scheduler/SlotSharingExecutionSlotAllocator.java ########## @@ -0,0 +1,268 @@ +/* + * 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.flink.runtime.scheduler; + +import org.apache.flink.runtime.clusterframework.types.SlotProfile; +import org.apache.flink.runtime.jobmanager.scheduler.Locality; +import org.apache.flink.runtime.jobmaster.LogicalSlot; +import org.apache.flink.runtime.jobmaster.SlotOwner; +import org.apache.flink.runtime.jobmaster.SlotRequestId; +import org.apache.flink.runtime.jobmaster.slotpool.DualKeyLinkedMap; +import org.apache.flink.runtime.jobmaster.slotpool.PhysicalSlot; +import org.apache.flink.runtime.jobmaster.slotpool.PhysicalSlotProvider; +import org.apache.flink.runtime.jobmaster.slotpool.PhysicalSlotRequest; +import org.apache.flink.runtime.jobmaster.slotpool.SingleLogicalSlot; +import org.apache.flink.runtime.scheduler.SharedSlotProfileRetriever.SharedSlotProfileRetrieverFactory; +import org.apache.flink.runtime.scheduler.strategy.ExecutionVertexID; +import org.apache.flink.util.FlinkException; +import org.apache.flink.util.Preconditions; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.util.Collection; +import java.util.HashMap; +import java.util.HashSet; +import java.util.List; +import java.util.Map; +import java.util.concurrent.CompletableFuture; +import java.util.stream.Collectors; +import java.util.stream.Stream; + +/** + * Allocates {@link LogicalSlot}s from physical shared slots. + * + * <p>The allocator maintains a shared slot for each {@link ExecutionSlotSharingGroup}. + * It allocates a physical slot for the shared slot and then allocates logical slots from it for scheduled tasks. + * The physical slot is lazily allocated for a shared slot, upon any hosted subtask asking for the shared slot. + * Each subsequent sharing subtask allocates a logical slot from the existing shared slot. The shared/physical slot + * can be released only if all the requested logical slots are released or canceled. + */ +class SlotSharingExecutionSlotAllocator implements ExecutionSlotAllocator { + private static final Logger LOG = LoggerFactory.getLogger(SlotSharingExecutionSlotAllocator.class); + + private final PhysicalSlotProvider slotProvider; + + private final boolean slotWillBeOccupiedIndefinitely; + + private final SlotSharingStrategy slotSharingStrategy; + + private final Map<ExecutionSlotSharingGroup, SharedSlot> sharedSlots; + + private final SharedSlotProfileRetrieverFactory sharedSlotProfileRetrieverFactory; + + SlotSharingExecutionSlotAllocator( + PhysicalSlotProvider slotProvider, + boolean slotWillBeOccupiedIndefinitely, + SlotSharingStrategy slotSharingStrategy, + SharedSlotProfileRetrieverFactory sharedSlotProfileRetrieverFactory) { + this.slotProvider = slotProvider; + this.slotWillBeOccupiedIndefinitely = slotWillBeOccupiedIndefinitely; + this.slotSharingStrategy = slotSharingStrategy; + this.sharedSlotProfileRetrieverFactory = sharedSlotProfileRetrieverFactory; + this.sharedSlots = new HashMap<>(); + } + + /** + * Creates logical {@link SlotExecutionVertexAssignment}s from physical shared slots. + * + * <p>The allocation has the following steps: + * <ol> + * <li>Map the executions to {@link ExecutionSlotSharingGroup}s using {@link SlotSharingStrategy}</li> + * <li>Check which {@link ExecutionSlotSharingGroup}s already have shared slot</li> + * <li>For all involved {@link ExecutionSlotSharingGroup}s which do not have a shared slot yet:</li> + * <li>Create a {@link SlotProfile} future using {@link SharedSlotProfileRetriever} and then</li> + * <li>Allocate a physical slot from the {@link PhysicalSlotProvider}</li> + * <li>Create a shared slot based on the returned physical slot futures</li> + * <li>Allocate logical slot futures for the executions from all corresponding shared slots.</li> + * <li>If a physical slot request fails, associated logical slot requests are canceled within the shared slot</li> + * <li>Generate {@link SlotExecutionVertexAssignment}s based on the logical slot futures and returns the results.</li> + * </ol> + * + * @param executionVertexSchedulingRequirements the requirements for scheduling the executions. + */ + @Override + public List<SlotExecutionVertexAssignment> allocateSlotsFor( + List<ExecutionVertexSchedulingRequirements> executionVertexSchedulingRequirements) { + List<ExecutionVertexID> executionVertexIds = executionVertexSchedulingRequirements + .stream() + .map(ExecutionVertexSchedulingRequirements::getExecutionVertexId) + .collect(Collectors.toList()); + + SharedSlotProfileRetriever sharedSlotProfileRetriever = sharedSlotProfileRetrieverFactory + .createFromBulk(new HashSet<>(executionVertexIds)); + Map<ExecutionVertexID, SlotExecutionVertexAssignment> assignments = executionVertexIds + .stream() + .collect(Collectors.groupingBy(slotSharingStrategy::getExecutionSlotSharingGroup)) + .entrySet() + .stream() + .flatMap(entry -> allocateLogicalSlotsFromSharedSlot(sharedSlotProfileRetriever, entry.getKey(), entry.getValue())) + .collect(Collectors.toMap(SlotExecutionVertexAssignment::getExecutionVertexId, a -> a)); + + return executionVertexIds.stream().map(assignments::get).collect(Collectors.toList()); + } + + @Override + public void cancel(ExecutionVertexID executionVertexId) { + ExecutionSlotSharingGroup executionSlotSharingGroup = + slotSharingStrategy.getExecutionSlotSharingGroup(executionVertexId); + Preconditions.checkNotNull( + executionSlotSharingGroup, + "There is no ExecutionSlotSharingGroup for ExecutionVertexID " + executionVertexId); + SharedSlot slot = sharedSlots.get(executionSlotSharingGroup); + if (slot != null) { + slot.cancelLogicalSlotRequest(executionVertexId); + } else { + LOG.debug("There is no slot for ExecutionSlotSharingGroup of ExecutionVertexID {}", executionVertexId); + } + } + + private Stream<? extends SlotExecutionVertexAssignment> allocateLogicalSlotsFromSharedSlot( + SharedSlotProfileRetriever sharedSlotProfileRetriever, + ExecutionSlotSharingGroup executionSlotSharingGroup, + Collection<ExecutionVertexID> executions) { + SharedSlot sharedSlot = getOrAllocateSharedSlot(executionSlotSharingGroup, sharedSlotProfileRetriever); + return executions.stream().map(sharedSlot::createAssignment); + } + + private SharedSlot getOrAllocateSharedSlot( + ExecutionSlotSharingGroup executionSlotSharingGroup, + SharedSlotProfileRetriever sharedSlotProfileRetriever) { + return sharedSlots + .computeIfAbsent(executionSlotSharingGroup, group -> { + SlotRequestId physicalSlotRequestId = new SlotRequestId(); + CompletableFuture<PhysicalSlot> physicalSlotFuture = sharedSlotProfileRetriever + .getSlotProfileFuture(group) + .thenCompose(slotProfile -> slotProvider.allocatePhysicalSlot( + new PhysicalSlotRequest(physicalSlotRequestId, slotProfile, slotWillBeOccupiedIndefinitely))) + .thenApply(PhysicalSlotRequest.Result::getPhysicalSlot); + return new SharedSlot(physicalSlotRequestId, group, physicalSlotFuture); + }); + } + + private class SharedSlot implements SlotOwner, PhysicalSlot.Payload { + private final SlotRequestId physicalSlotRequestId; + + private final ExecutionSlotSharingGroup executionSlotSharingGroup; + + private final CompletableFuture<PhysicalSlot> slotContextFuture; + + private final DualKeyLinkedMap<ExecutionVertexID, SlotRequestId, SlotExecutionVertexAssignment> requestedLogicalSlots; + + private SharedSlot( + SlotRequestId physicalSlotRequestId, + ExecutionSlotSharingGroup executionSlotSharingGroup, + CompletableFuture<PhysicalSlot> slotContextFuture) { + this.physicalSlotRequestId = physicalSlotRequestId; + this.executionSlotSharingGroup = executionSlotSharingGroup; + this.slotContextFuture = slotContextFuture.thenApply(physicalSlot -> { + Preconditions.checkState( + physicalSlot.tryAssignPayload(this), + "Unexpected physical slot payload assignment failure!"); + return physicalSlot; + }); + this.requestedLogicalSlots = new DualKeyLinkedMap<>(executionSlotSharingGroup.getExecutionVertexIds().size()); + } + + SlotExecutionVertexAssignment createAssignment(ExecutionVertexID executionVertexId) { + Preconditions.checkArgument(executionSlotSharingGroup.getExecutionVertexIds().contains(executionVertexId)); + SlotRequestId logicalSlotRequestId = new SlotRequestId(); + CompletableFuture<LogicalSlot> logicalSlotFuture = allocateLogicalSlot(logicalSlotRequestId, executionVertexId); + SlotExecutionVertexAssignment assignment = new SlotExecutionVertexAssignment(executionVertexId, logicalSlotFuture); + requestedLogicalSlots.put( + executionVertexId, + logicalSlotRequestId, + assignment); + return assignment; + } + + private CompletableFuture<LogicalSlot> allocateLogicalSlot( + SlotRequestId logicalSlotRequestId, + ExecutionVertexID executionVertexId) { + String logMessageBase = getLogicalSlotString(logicalSlotRequestId, executionVertexId); + LOG.debug("Request a {}", logMessageBase); + CompletableFuture<LogicalSlot> logicalSlotFuture = slotContextFuture.thenApply(physicalSlot -> { + LOG.debug("Allocated {}", logMessageBase); + return new SingleLogicalSlot( + logicalSlotRequestId, + physicalSlot, + null, + Locality.UNKNOWN, + this, + slotWillBeOccupiedIndefinitely); + }); + logicalSlotFuture.exceptionally(cause -> { + LOG.debug("Failed {}", logMessageBase); + cancelLogicalSlotRequest(logicalSlotRequestId); + return null; + }); + return logicalSlotFuture; + } + + void cancelLogicalSlotRequest(ExecutionVertexID executionVertexID) { + cancelLogicalSlotRequest(requestedLogicalSlots.getKeyBByKeyA(executionVertexID)); + } + + void cancelLogicalSlotRequest(SlotRequestId logicalSlotRequestId) { + SlotExecutionVertexAssignment assignment = requestedLogicalSlots.getValueByKeyB(logicalSlotRequestId); + if (assignment != null) { + LOG.debug("Cancel {}", getLogicalSlotString(logicalSlotRequestId, assignment.getExecutionVertexId())); + assignment.getLogicalSlotFuture().cancel(false); + requestedLogicalSlots.removeKeyB(logicalSlotRequestId); + } else { + LOG.debug("No SlotExecutionVertexAssignment for logical {} from physical %s", logicalSlotRequestId); + } + if (requestedLogicalSlots.values().isEmpty()) { + sharedSlots.remove(executionSlotSharingGroup); + slotProvider.cancelSlotRequest( + physicalSlotRequestId, + new FlinkException("Slot is being returned from SlotSharingExecutionSlotAllocator.")); + } + } + + @Override + public void returnLogicalSlot(LogicalSlot logicalSlot) { + cancelLogicalSlotRequest(logicalSlot.getSlotRequestId()); + } + + @Override + public void release(Throwable cause) { + for (SlotExecutionVertexAssignment assignment : requestedLogicalSlots.values()) { + ExecutionVertexID executionVertexId = assignment.getExecutionVertexId(); + LOG.debug("Release {}", getLogicalSlotString(requestedLogicalSlots.getKeyBByKeyA(executionVertexId), executionVertexId)); + assignment Review comment: ok, I also expected that the release call only comes from an allocated physical slot, so no need to touch it and logical slots. I was confused because the code in this method does not depend on this assumption. I will add the sanity checks to make it explicit. ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
