Thesharing commented on a change in pull request #16688: URL: https://github.com/apache/flink/pull/16688#discussion_r686444766
########## File path: flink-runtime/src/main/java/org/apache/flink/runtime/executiongraph/failover/flip1/SchedulingPipelinedRegionComputeUtil.java ########## @@ -0,0 +1,162 @@ +/* + * 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.executiongraph.failover.flip1; + +import org.apache.flink.runtime.jobgraph.IntermediateResultPartitionID; +import org.apache.flink.runtime.scheduler.strategy.ConsumedPartitionGroup; +import org.apache.flink.runtime.scheduler.strategy.ConsumerVertexGroup; +import org.apache.flink.runtime.scheduler.strategy.ExecutionVertexID; +import org.apache.flink.runtime.scheduler.strategy.SchedulingExecutionVertex; +import org.apache.flink.runtime.scheduler.strategy.SchedulingPipelinedRegion; +import org.apache.flink.runtime.scheduler.strategy.SchedulingResultPartition; + +import java.util.ArrayList; +import java.util.Collections; +import java.util.HashSet; +import java.util.IdentityHashMap; +import java.util.List; +import java.util.Map; +import java.util.Set; +import java.util.function.Function; + +import static org.apache.flink.runtime.executiongraph.failover.flip1.PipelinedRegionComputeUtil.buildRawRegions; +import static org.apache.flink.runtime.executiongraph.failover.flip1.PipelinedRegionComputeUtil.mergeRegions; +import static org.apache.flink.runtime.executiongraph.failover.flip1.PipelinedRegionComputeUtil.uniqueRegions; +import static org.apache.flink.util.Preconditions.checkState; + +/** Utils for computing {@link SchedulingPipelinedRegion}s. */ +public final class SchedulingPipelinedRegionComputeUtil { + + public static Set<Set<SchedulingExecutionVertex>> computePipelinedRegions( + final Iterable<? extends SchedulingExecutionVertex> topologicallySortedVertices, + final Function<ExecutionVertexID, ? extends SchedulingExecutionVertex> + executionVertexRetriever, + final Function<IntermediateResultPartitionID, ? extends SchedulingResultPartition> + resultPartitionRetriever) { + + final Map<SchedulingExecutionVertex, Set<SchedulingExecutionVertex>> vertexToRegion = + buildRawRegions( + topologicallySortedVertices, + vertex -> + getNonReconnectableConsumedResults( + vertex, resultPartitionRetriever)); + + return mergeRegionsOnCycles(vertexToRegion, executionVertexRetriever); + } + + /** + * Merge the regions base on <a + * href="https://en.wikipedia.org/wiki/Tarjan%27s_strongly_connected_components_algorithm";> + * Tarjan's strongly connected components algorithm</a>. For more details please see <a + * href="https://issues.apache.org/jira/browse/FLINK-17330";>FLINK-17330</a>. + */ + private static Set<Set<SchedulingExecutionVertex>> mergeRegionsOnCycles( + final Map<SchedulingExecutionVertex, Set<SchedulingExecutionVertex>> vertexToRegion, + final Function<ExecutionVertexID, ? extends SchedulingExecutionVertex> + executionVertexRetriever) { + + final List<Set<SchedulingExecutionVertex>> regionList = + new ArrayList<>(uniqueRegions(vertexToRegion)); + final List<List<Integer>> outEdges = + buildOutEdgesDesc(vertexToRegion, regionList, executionVertexRetriever); + final Set<Set<Integer>> sccs = + StronglyConnectedComponentsComputeUtils.computeStronglyConnectedComponents( + outEdges.size(), outEdges); + + final Set<Set<SchedulingExecutionVertex>> mergedRegions = + Collections.newSetFromMap(new IdentityHashMap<>()); + for (Set<Integer> scc : sccs) { + checkState(scc.size() > 0); + + Set<SchedulingExecutionVertex> mergedRegion = new HashSet<>(); + for (int regionIndex : scc) { + mergedRegion = + mergeRegions(mergedRegion, regionList.get(regionIndex), vertexToRegion); + } + mergedRegions.add(mergedRegion); + } + + return mergedRegions; + } + + private static List<List<Integer>> buildOutEdgesDesc( + final Map<SchedulingExecutionVertex, Set<SchedulingExecutionVertex>> vertexToRegion, + final List<Set<SchedulingExecutionVertex>> regionList, + final Function<ExecutionVertexID, ? extends SchedulingExecutionVertex> + executionVertexRetriever) { + + final Map<Set<SchedulingExecutionVertex>, Integer> regionIndices = new IdentityHashMap<>(); + for (int i = 0; i < regionList.size(); i++) { + regionIndices.put(regionList.get(i), i); + } + + final List<List<Integer>> outEdges = new ArrayList<>(regionList.size()); + for (Set<SchedulingExecutionVertex> currentRegion : regionList) { + final List<Integer> currentRegionOutEdges = new ArrayList<>(); + for (SchedulingExecutionVertex vertex : currentRegion) { + for (SchedulingResultPartition producedResult : vertex.getProducedResults()) { + if (!producedResult.getResultType().isReconnectable()) { + continue; + } + for (ConsumerVertexGroup consumerVertexGroup : + producedResult.getConsumerVertexGroups()) { + for (ExecutionVertexID consumerVertexId : consumerVertexGroup) { + SchedulingExecutionVertex consumerVertex = + executionVertexRetriever.apply(consumerVertexId); + // Skip the ConsumerVertexGroup if its vertices are outside current + // regions and cannot be merged + if (!vertexToRegion.containsKey(consumerVertex)) { + break; + } + if (!currentRegion.contains(consumerVertex)) { + currentRegionOutEdges.add( + regionIndices.get(vertexToRegion.get(consumerVertex))); + } + } + } + } + } + outEdges.add(currentRegionOutEdges); + } + + return outEdges; + } + + private static Iterable<SchedulingResultPartition> getNonReconnectableConsumedResults( + SchedulingExecutionVertex vertex, + Function<IntermediateResultPartitionID, ? extends SchedulingResultPartition> + resultPartitionRetriever) { + List<SchedulingResultPartition> nonReconnectableConsumedResults = + new ArrayList<>(vertex.getConsumedPartitionGroups().size()); Review comment: Thank you for pointing this out. It seems that setting the initial size of the list the same as the count of ConsumedPartitionGroups is not good for rescale edges. I'll fix it. -- 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. To unsubscribe, e-mail: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
