ilooner commented on a change in pull request #1606: DRILL-6845: Semi-Hash-Join to skip incoming build duplicates, automatically stop skipping if too few URL: https://github.com/apache/drill/pull/1606#discussion_r248160231
########## File path: exec/java-exec/src/main/java/org/apache/drill/exec/physical/impl/join/HashJoinSpillControlImpl.java ########## @@ -0,0 +1,238 @@ +/* + * 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.drill.exec.physical.impl.join; + + import org.apache.drill.exec.ExecConstants; + import org.apache.drill.exec.memory.BufferAllocator; + import org.apache.drill.exec.ops.FragmentContext; + import org.apache.drill.exec.record.RecordBatch; + import org.apache.drill.exec.record.RecordBatchMemoryManager; + import org.slf4j.Logger; + import org.slf4j.LoggerFactory; + + import javax.annotation.Nullable; + import java.util.Set; + + import static org.apache.drill.exec.record.JoinBatchMemoryManager.LEFT_INDEX; + import static org.apache.drill.exec.record.JoinBatchMemoryManager.RIGHT_INDEX; + +/** + * This class is currently used only for Semi-Hash-Join that avoids duplicates by the use of a hash table + * The method {@link HashJoinMemoryCalculator.HashJoinSpillControl#shouldSpill()} returns true if the memory available now to the allocator if not enough + * to hold (a multiple of, for safety) a new allocated batch + */ +public class HashJoinSpillControlImpl implements HashJoinMemoryCalculator.BuildSidePartitioning { + private static final Logger logger = LoggerFactory.getLogger(HashJoinSpillControlImpl.class); + + private BufferAllocator allocator; + private int recordsPerBatch; + private int minBatchesInAvailableMemory; + private RecordBatchMemoryManager batchMemoryManager; + private int initialPartitions; + private int numPartitions; + private int recordsPerPartitionBatchProbe; + private FragmentContext context; + HashJoinMemoryCalculator.PartitionStatSet partitionStatSet; + + HashJoinSpillControlImpl(BufferAllocator allocator, int recordsPerBatch, int minBatchesInAvailableMemory, RecordBatchMemoryManager batchMemoryManager, FragmentContext context) { + this.allocator = allocator; + this.recordsPerBatch = recordsPerBatch; + this.minBatchesInAvailableMemory = minBatchesInAvailableMemory; + this.batchMemoryManager = batchMemoryManager; + this.context = context; + } + + @Override + public boolean shouldSpill() { + // Expected new batch size like the current, plus the Hash Values vector (4 bytes per HV) + long batchSize = ( batchMemoryManager.getRecordBatchSizer(RIGHT_INDEX).getRowAllocWidth() + 4 ) * recordsPerBatch; + long reserveForOutgoing = batchMemoryManager.getOutputBatchSize(); + long memoryAvailableNow = allocator.getLimit() - allocator.getAllocatedMemory() - reserveForOutgoing; + boolean needsSpill = minBatchesInAvailableMemory * batchSize > memoryAvailableNow; + if ( needsSpill ) { + logger.debug("should spill now - batch size {}, mem avail {}, reserved for outgoing {}", batchSize, memoryAvailableNow, reserveForOutgoing); + } + return needsSpill; // go spill if too little memory is available + } + + @Override + public void initialize(boolean firstCycle, + boolean reserveHash, + RecordBatch buildSideBatch, + RecordBatch probeSideBatch, + Set<String> joinColumns, + boolean probeEmpty, + long memoryAvailable, + int initialPartitions, + int recordsPerPartitionBatchBuild, + int recordsPerPartitionBatchProbe, + int maxBatchNumRecordsBuild, + int maxBatchNumRecordsProbe, + int outputBatchSize, + double loadFactor) { + this.initialPartitions = initialPartitions; + this.recordsPerPartitionBatchProbe = recordsPerPartitionBatchProbe; + + calculateMemoryUsage(); + } + + @Override + public void setPartitionStatSet(HashJoinMemoryCalculator.PartitionStatSet partitionStatSet) { + this.partitionStatSet = partitionStatSet; + } + + @Override + public int getNumPartitions() { + return numPartitions; + } + + /** + * Calculate the number of partitions possible for the given available memory + * start at initialPartitions and adjust down (in powers of 2) as needed + */ + private void calculateMemoryUsage() { + long reserveForOutgoing = batchMemoryManager.getOutputBatchSize(); + long memoryAvailableNow = allocator.getLimit() - allocator.getAllocatedMemory() - reserveForOutgoing; + + // Expected new batch size like the current, plus the Hash Values vector (4 bytes per HV) + int buildBatchSize = ( batchMemoryManager.getRecordBatchSizer(RIGHT_INDEX).getRowAllocWidth() + 4 ) * recordsPerBatch; + int hashTableSize = buildBatchSize /* the keys in the HT */ + + 4 * (int)context.getOptions().getLong(ExecConstants.MIN_HASH_TABLE_SIZE_KEY) /* the initial hash table buckets */ + + (2 + 2) * recordsPerBatch; /* the hash-values and the links */ + int probeBatchSize = ( batchMemoryManager.getRecordBatchSizer(LEFT_INDEX).getRowAllocWidth() + 4 ) * recordsPerBatch; + + long memoryNeededPerPartition = Integer.max(buildBatchSize + hashTableSize, probeBatchSize); + + for ( numPartitions = initialPartitions; numPartitions > 2; numPartitions /= 2 ) { // need at least 2 + // each partition needs at least one internal build batch, and a minimum hash-table + // ( or an internal probe batch, for a spilled partition during probe phase ) + // adding "min batches" to create some safety slack + if ( memoryAvailableNow > + ( numPartitions + minBatchesInAvailableMemory ) * memoryNeededPerPartition ) { + break; // got enough memory + } + } + logger.debug("Spill control chosen to use {} partitions", numPartitions); + } + + @Override + public long getBuildReservedMemory() { + return 0; + } + + @Override + public long getMaxReservedMemory() { + return 0; + } + + @Override + public String makeDebugString() { + return "Spill Control " + HashJoinMemoryCalculatorImpl.HashJoinSpillControl.class.getCanonicalName(); + } + + @Nullable + @Override + public HashJoinMemoryCalculator.PostBuildCalculations next() { + return new SpillControlPostBuildCalculationsImpl(recordsPerPartitionBatchProbe, + allocator, recordsPerBatch, minBatchesInAvailableMemory, batchMemoryManager, partitionStatSet); + } + + @Override + public HashJoinState getState() { + return HashJoinState.BUILD_SIDE_PARTITIONING; + } + + + /** + * The purpose of this class is to provide the method {@link #shouldSpill} that ensures that enough memory is available to + * hold all the probe incoming batches for those partitions that spilled (else need to spill more of them, for more memory). + */ + public static class SpillControlPostBuildCalculationsImpl implements HashJoinMemoryCalculator.PostBuildCalculations { + private static final Logger logger = LoggerFactory.getLogger(SpillControlPostBuildCalculationsImpl.class); + + private final int recordsPerPartitionBatchProbe; + private BufferAllocator allocator; + private int recordsPerBatch; + private int minBatchesInAvailableMemory; + private RecordBatchMemoryManager batchMemoryManager; + private boolean probeEmpty; + private final HashJoinMemoryCalculator.PartitionStatSet buildPartitionStatSet; + + + public SpillControlPostBuildCalculationsImpl(final int recordsPerPartitionBatchProbe, + BufferAllocator allocator, int recordsPerBatch, int minBatchesInAvailableMemory, + RecordBatchMemoryManager batchMemoryManager, + final HashJoinMemoryCalculator.PartitionStatSet buildPartitionStatSet) { + this.allocator = allocator; + this.recordsPerBatch = recordsPerBatch; + this.minBatchesInAvailableMemory = minBatchesInAvailableMemory; + this.batchMemoryManager = batchMemoryManager; + this.recordsPerPartitionBatchProbe = recordsPerPartitionBatchProbe; + this.buildPartitionStatSet = buildPartitionStatSet; + } + + @Override + public void initialize(boolean hasProbeData) { + this.probeEmpty = hasProbeData; + } + + + @Override + public int getProbeRecordsPerBatch() { + return recordsPerPartitionBatchProbe; + } + + @Override + public boolean shouldSpill() { + int numPartitionsSpilled = buildPartitionStatSet.getNumSpilledPartitions(); + if ( numPartitionsSpilled == 0 ) { return false; } // no extra memory is needed if all the build side is in memory + if ( probeEmpty ) { return false; } // no probe side data + // Expected new batch size like the current, plus the Hash Values vector (4 bytes per HV) + long batchSize = ( batchMemoryManager.getRecordBatchSizer(LEFT_INDEX).getRowAllocWidth() + 4 ) * recordsPerBatch; Review comment: Please use BatchSizePredictorHere ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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