| /* |
| * 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.samza.execution; |
| |
| import com.google.common.annotations.VisibleForTesting; |
| import com.google.common.collect.HashMultimap; |
| import com.google.common.collect.Multimap; |
| import java.util.Collection; |
| import java.util.HashSet; |
| import java.util.Optional; |
| import java.util.Set; |
| import org.apache.samza.SamzaException; |
| import org.apache.samza.config.Config; |
| import org.apache.samza.config.JobConfig; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import static org.apache.samza.execution.ExecutionPlanner.StreamSet; |
| |
| |
| /** |
| * {@link IntermediateStreamManager} calculates intermediate stream partitions based on the high-level application graph. |
| */ |
| class IntermediateStreamManager { |
| |
| private static final Logger log = LoggerFactory.getLogger(IntermediateStreamManager.class); |
| |
| private final Config config; |
| |
| @VisibleForTesting |
| static final int MAX_INFERRED_PARTITIONS = 256; |
| |
| IntermediateStreamManager(Config config) { |
| this.config = config; |
| } |
| |
| /** |
| * Calculates the number of partitions of all intermediate streams |
| */ |
| /* package private */ void calculatePartitions(JobGraph jobGraph, Collection<StreamSet> joinedStreamSets) { |
| |
| // Set partition count of intermediate streams participating in joins |
| setJoinedIntermediateStreamPartitions(joinedStreamSets); |
| |
| // Set partition count of intermediate streams not participating in joins |
| setIntermediateStreamPartitions(jobGraph); |
| |
| // Validate partition counts were assigned for all intermediate streams |
| validateIntermediateStreamPartitions(jobGraph); |
| } |
| |
| /** |
| * Sets partition counts of intermediate streams which have not been assigned partition counts. |
| */ |
| private void setIntermediateStreamPartitions(JobGraph jobGraph) { |
| final String defaultPartitionsConfigProperty = JobConfig.JOB_INTERMEDIATE_STREAM_PARTITIONS; |
| int partitions = config.getInt(defaultPartitionsConfigProperty, StreamEdge.PARTITIONS_UNKNOWN); |
| if (partitions == StreamEdge.PARTITIONS_UNKNOWN) { |
| // use the following simple algo to figure out the partitions |
| // partition = MAX(MAX(Input topic partitions), MAX(Output topic partitions)) |
| // partition will be further bounded by MAX_INFERRED_PARTITIONS. |
| // This is important when running in hadoop where an HDFS input can have lots of files (partitions). |
| int maxInPartitions = maxPartitions(jobGraph.getInputStreams()); |
| int maxOutPartitions = maxPartitions(jobGraph.getOutputStreams()); |
| partitions = Math.max(maxInPartitions, maxOutPartitions); |
| |
| if (partitions > MAX_INFERRED_PARTITIONS) { |
| partitions = MAX_INFERRED_PARTITIONS; |
| log.warn(String.format("Inferred intermediate stream partition count %d is greater than the max %d. Using the max.", |
| partitions, MAX_INFERRED_PARTITIONS)); |
| } |
| } else { |
| // Reject any zero or other negative values explicitly specified in config. |
| if (partitions <= 0) { |
| throw new SamzaException(String.format("Invalid value %d specified for config property %s", partitions, |
| defaultPartitionsConfigProperty)); |
| } |
| |
| log.info("Using partition count value {} specified for config property {}", partitions, |
| defaultPartitionsConfigProperty); |
| } |
| |
| for (StreamEdge edge : jobGraph.getIntermediateStreamEdges()) { |
| if (edge.getPartitionCount() <= 0) { |
| log.info("Set the partition count for intermediate stream {} to {}.", edge.getName(), partitions); |
| edge.setPartitionCount(partitions); |
| } |
| } |
| } |
| |
| /** |
| * Sets partition counts of intermediate streams participating in joins operations. |
| */ |
| private static void setJoinedIntermediateStreamPartitions(Collection<StreamSet> joinedStreamSets) { |
| // Map every intermediate stream to all the stream-sets it appears in |
| Multimap<StreamEdge, StreamSet> intermediateStreamToStreamSets = HashMultimap.create(); |
| for (StreamSet streamSet : joinedStreamSets) { |
| for (StreamEdge streamEdge : streamSet.getStreamEdges()) { |
| if (streamEdge.getPartitionCount() == StreamEdge.PARTITIONS_UNKNOWN) { |
| intermediateStreamToStreamSets.put(streamEdge, streamSet); |
| } |
| } |
| } |
| |
| Set<StreamSet> streamSets = new HashSet<>(joinedStreamSets); |
| Set<StreamSet> processedStreamSets = new HashSet<>(); |
| |
| while (!streamSets.isEmpty()) { |
| // Retrieve and remove one stream set |
| StreamSet streamSet = streamSets.iterator().next(); |
| streamSets.remove(streamSet); |
| |
| // Find any stream with set partitions in this set |
| Optional<StreamEdge> streamWithSetPartitions = |
| streamSet.getStreamEdges().stream() |
| .filter(streamEdge -> streamEdge.getPartitionCount() != StreamEdge.PARTITIONS_UNKNOWN) |
| .findAny(); |
| |
| if (streamWithSetPartitions.isPresent()) { |
| // Mark this stream-set as processed since we won't need to re-examine it ever again. |
| // It is important that we do this first before processing any intermediate streams |
| // that may be in this stream-set. |
| processedStreamSets.add(streamSet); |
| |
| // Set partitions of all intermediate streams in this set (if any) |
| int partitions = streamWithSetPartitions.get().getPartitionCount(); |
| for (StreamEdge streamEdge : streamSet.getStreamEdges()) { |
| if (streamEdge.getPartitionCount() == StreamEdge.PARTITIONS_UNKNOWN) { |
| streamEdge.setPartitionCount(partitions); |
| // Add all unprocessed stream-sets in which this intermediate stream appears |
| Collection<StreamSet> streamSetsIncludingIntStream = intermediateStreamToStreamSets.get(streamEdge); |
| streamSetsIncludingIntStream.stream() |
| .filter(s -> !processedStreamSets.contains(s)) |
| .forEach(streamSets::add); |
| } |
| } |
| } |
| } |
| } |
| |
| /** |
| * Ensures all intermediate streams have been assigned partition counts. |
| */ |
| private static void validateIntermediateStreamPartitions(JobGraph jobGraph) { |
| for (StreamEdge edge : jobGraph.getIntermediateStreamEdges()) { |
| if (edge.getPartitionCount() <= 0) { |
| throw new SamzaException(String.format("Failed to assign valid partition count to Stream %s", edge.getName())); |
| } |
| } |
| } |
| |
| /* package private */ static int maxPartitions(Collection<StreamEdge> edges) { |
| return edges.stream().mapToInt(StreamEdge::getPartitionCount).max().orElse(StreamEdge.PARTITIONS_UNKNOWN); |
| } |
| } |