tibrewalpratik17 commented on code in PR #13347: URL: https://github.com/apache/pinot/pull/13347#discussion_r1714403027
########## pinot-segment-local/src/main/java/org/apache/pinot/segment/local/upsert/ConcurrentMapPartitionUpsertMetadataManagerForConsistentDeletes.java: ########## @@ -0,0 +1,391 @@ +/** + * 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.pinot.segment.local.upsert; + +import com.google.common.annotations.VisibleForTesting; +import java.util.HashMap; +import java.util.HashSet; +import java.util.Iterator; +import java.util.Map; +import java.util.Objects; +import java.util.Set; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.atomic.AtomicBoolean; +import java.util.concurrent.atomic.AtomicInteger; +import javax.annotation.Nullable; +import javax.annotation.concurrent.ThreadSafe; +import org.apache.pinot.common.metrics.ServerMeter; +import org.apache.pinot.segment.local.indexsegment.immutable.ImmutableSegmentImpl; +import org.apache.pinot.segment.local.segment.readers.LazyRow; +import org.apache.pinot.segment.local.utils.HashUtils; +import org.apache.pinot.segment.spi.ImmutableSegment; +import org.apache.pinot.segment.spi.IndexSegment; +import org.apache.pinot.segment.spi.MutableSegment; +import org.apache.pinot.segment.spi.index.mutable.ThreadSafeMutableRoaringBitmap; +import org.apache.pinot.spi.data.readers.GenericRow; +import org.apache.pinot.spi.data.readers.PrimaryKey; +import org.roaringbitmap.buffer.MutableRoaringBitmap; + + +/** + * Implementation of {@link PartitionUpsertMetadataManager} that is backed by a {@link ConcurrentHashMap} and ensures + * consistent deletions. This should be used when the table is configured with 'enableConsistentDeletes' set to true. + * + * Consistent deletion ensures that when deletedKeysTTL is enabled with UpsertCompaction, the key metadata is + * removed from the HashMap only after all other records in the old segments are compacted. This guarantees + * data consistency. Without this, there can be a scenario where a deleted record is compacted first, while an + * old record remains non-compacted in a previous segment. During a server restart, this could lead to the old + * record reappearing. For the end-user, this would result in a data loss or inconsistency scenario, as the + * record was marked for deletion. + */ +@SuppressWarnings({"rawtypes", "unchecked"}) +@ThreadSafe +public class ConcurrentMapPartitionUpsertMetadataManagerForConsistentDeletes + extends BasePartitionUpsertMetadataManager { + + @VisibleForTesting + final ConcurrentHashMap<Object, ConcurrentMapPartitionUpsertMetadataManagerForConsistentDeletes.RecordLocation> + _primaryKeyToRecordLocationMap = new ConcurrentHashMap<>(); + // Used to initialize a reference to previous row for merging in partial upsert + private final LazyRow _reusePreviousRow = new LazyRow(); + private final Map<String, Object> _reuseMergeResultHolder = new HashMap<>(); + + public ConcurrentMapPartitionUpsertMetadataManagerForConsistentDeletes(String tableNameWithType, int partitionId, + UpsertContext context) { + super(tableNameWithType, partitionId, context); + } + + @Override + protected long getNumPrimaryKeys() { + return _primaryKeyToRecordLocationMap.size(); + } + + @Override + protected void doAddOrReplaceSegment(ImmutableSegmentImpl segment, ThreadSafeMutableRoaringBitmap validDocIds, + @Nullable ThreadSafeMutableRoaringBitmap queryableDocIds, Iterator<RecordInfo> recordInfoIterator, + @Nullable IndexSegment oldSegment, @Nullable MutableRoaringBitmap validDocIdsForOldSegment) { + String segmentName = segment.getSegmentName(); + segment.enableUpsert(this, validDocIds, queryableDocIds); + + AtomicInteger numKeysInWrongSegment = new AtomicInteger(); + while (recordInfoIterator.hasNext()) { + RecordInfo recordInfo = recordInfoIterator.next(); + int newDocId = recordInfo.getDocId(); + Comparable newComparisonValue = recordInfo.getComparisonValue(); + _primaryKeyToRecordLocationMap.compute(HashUtils.hashPrimaryKey(recordInfo.getPrimaryKey(), _hashFunction), + (primaryKey, currentRecordLocation) -> { + if (currentRecordLocation != null) { + // Existing primary key + IndexSegment currentSegment = currentRecordLocation.getSegment(); + int currentDocId = currentRecordLocation.getDocId(); + Comparable currentComparisonValue = currentRecordLocation.getComparisonValue(); + int comparisonResult = newComparisonValue.compareTo(currentComparisonValue); + int currentDistinctSegmentCount = currentRecordLocation.getDistinctSegmentCount(); + + // The current record is in the same segment + // Update the record location when there is a tie to keep the newer record. Note that the record info + // iterator will return records with incremental doc ids. + if (currentSegment == segment) { + if (comparisonResult >= 0) { + replaceDocId(segment, validDocIds, queryableDocIds, currentDocId, newDocId, recordInfo); + return new ConcurrentMapPartitionUpsertMetadataManagerForConsistentDeletes.RecordLocation(segment, + newDocId, newComparisonValue, currentDistinctSegmentCount); + } else { + return currentRecordLocation; + } + } + + // The current record is in an old segment being replaced + // This could happen when committing a consuming segment, or reloading a completed segment. In this + // case, we want to update the record location when there is a tie because the record locations should + // point to the new added segment instead of the old segment being replaced. Also, do not update the valid + // doc ids for the old segment because it has not been replaced yet. We pass in an optional valid doc ids + // snapshot for the old segment, which can be updated and used to track the docs not replaced yet. + if (currentSegment == oldSegment) { + if (comparisonResult >= 0) { + addDocId(segment, validDocIds, queryableDocIds, newDocId, recordInfo); + if (validDocIdsForOldSegment != null) { + validDocIdsForOldSegment.remove(currentDocId); + } + return new RecordLocation(segment, newDocId, newComparisonValue, + RecordLocation.incrementSegmentCount(currentDistinctSegmentCount)); + } else { + return new RecordLocation(currentSegment, currentDocId, currentComparisonValue, + RecordLocation.incrementSegmentCount(currentDistinctSegmentCount)); + } + } + + // This should not happen because the previously replaced segment should have all keys removed. We still + // handle it here, and also track the number of keys not properly replaced previously. + String currentSegmentName = currentSegment.getSegmentName(); + if (currentSegmentName.equals(segmentName)) { + numKeysInWrongSegment.getAndIncrement(); + if (comparisonResult >= 0) { + addDocId(segment, validDocIds, queryableDocIds, newDocId, recordInfo); + return new RecordLocation(segment, newDocId, newComparisonValue, + RecordLocation.incrementSegmentCount(currentDistinctSegmentCount)); + } else { + return currentRecordLocation; + } + } + + // The current record is in a different segment + // Update the record location when getting a newer comparison value, or the value is the same as the + // current value, but the segment has a larger sequence number (the segment is newer than the current + // segment). + if (comparisonResult > 0 || (comparisonResult == 0 && shouldReplaceOnComparisonTie(segmentName, + currentSegmentName, segment.getSegmentMetadata().getIndexCreationTime(), + currentSegment.getSegmentMetadata().getIndexCreationTime()))) { + replaceDocId(segment, validDocIds, queryableDocIds, currentSegment, currentDocId, newDocId, recordInfo); + return new RecordLocation(segment, newDocId, newComparisonValue, + RecordLocation.incrementSegmentCount(currentDistinctSegmentCount)); + } else { + return new RecordLocation(currentSegment, currentDocId, currentComparisonValue, + RecordLocation.incrementSegmentCount(currentDistinctSegmentCount)); + } + } else { + // New primary key + addDocId(segment, validDocIds, queryableDocIds, newDocId, recordInfo); + return new RecordLocation(segment, newDocId, newComparisonValue, 1); + } + }); + } + int numKeys = numKeysInWrongSegment.get(); + if (numKeys > 0) { + _logger.warn("Found {} primary keys in the wrong segment when adding segment: {}", numKeys, segmentName); + _serverMetrics.addMeteredTableValue(_tableNameWithType, ServerMeter.UPSERT_KEYS_IN_WRONG_SEGMENT, numKeys); + } + } + + @Override + protected void addSegmentWithoutUpsert(ImmutableSegmentImpl segment, ThreadSafeMutableRoaringBitmap validDocIds, + @Nullable ThreadSafeMutableRoaringBitmap queryableDocIds, Iterator<RecordInfo> recordInfoIterator) { + throw new UnsupportedOperationException("Consistent-deletion does not support preloading of segments."); + } + + @Override + protected void doRemoveSegment(IndexSegment segment) { + String segmentName = segment.getSegmentName(); + _logger.info("Removing {} segment: {}, current primary key count: {}", + segment instanceof ImmutableSegment ? "immutable" : "mutable", segmentName, getNumPrimaryKeys()); + long startTimeMs = System.currentTimeMillis(); + + try ( + UpsertUtils.PrimaryKeyReader primaryKeyReader = new UpsertUtils.PrimaryKeyReader(segment, _primaryKeyColumns)) { + removeSegment(segment, + UpsertUtils.getPrimaryKeyIterator(primaryKeyReader, segment.getSegmentMetadata().getTotalDocs())); + } catch (Exception e) { + throw new RuntimeException( + String.format("Caught exception while removing segment: %s, table: %s", segment.getSegmentName(), + _tableNameWithType), e); + } + + // Update metrics + long numPrimaryKeys = getNumPrimaryKeys(); + updatePrimaryKeyGauge(numPrimaryKeys); + _logger.info("Finished removing segment: {} in {}ms, current primary key count: {}", segmentName, + System.currentTimeMillis() - startTimeMs, numPrimaryKeys); + } + + @Override + protected void removeSegment(IndexSegment segment, Iterator<PrimaryKey> primaryKeyIterator) { + Set<Object> deDuplicatedPrimaryKeys = new HashSet<>(); + while (primaryKeyIterator.hasNext()) { + PrimaryKey primaryKey = primaryKeyIterator.next(); + _primaryKeyToRecordLocationMap.computeIfPresent(HashUtils.hashPrimaryKey(primaryKey, _hashFunction), + (pk, recordLocation) -> { + if (deDuplicatedPrimaryKeys.contains(pk)) { + return recordLocation; + } + deDuplicatedPrimaryKeys.add(pk); + if (recordLocation.getSegment() == segment) { + return null; + } + return new RecordLocation(recordLocation.getSegment(), recordLocation.getDocId(), + recordLocation.getComparisonValue(), + RecordLocation.decrementSegmentCount(recordLocation.getDistinctSegmentCount())); + }); + } + } + + @Override + public void doRemoveExpiredPrimaryKeys() { + AtomicInteger numDeletedTTLKeysRemoved = new AtomicInteger(); + double largestSeenComparisonValue = _largestSeenComparisonValue.get(); + double deletedKeysThreshold; + if (_deletedKeysTTL > 0) { + deletedKeysThreshold = largestSeenComparisonValue - _deletedKeysTTL; + } else { + deletedKeysThreshold = Double.MIN_VALUE; + } + + _primaryKeyToRecordLocationMap.forEach((primaryKey, recordLocation) -> { + double comparisonValue = ((Number) recordLocation.getComparisonValue()).doubleValue(); + // We need to verify that the record belongs to only one segment. If a record is part of multiple segments, + // an issue can arise where the upsert compaction might first process the segment containing the delete record + // while the previous segment(s) are not compacted. Upon restart, this can inadvertently revive the key + // that was originally marked for deletion. + if (_deletedKeysTTL > 0 && comparisonValue < deletedKeysThreshold + && recordLocation.getDistinctSegmentCount() <= 1) { + ThreadSafeMutableRoaringBitmap currentQueryableDocIds = recordLocation.getSegment().getQueryableDocIds(); + // if key not part of queryable doc id, it means it is deleted + if (currentQueryableDocIds != null && !currentQueryableDocIds.contains(recordLocation.getDocId())) { + _primaryKeyToRecordLocationMap.remove(primaryKey, recordLocation); + removeDocId(recordLocation.getSegment(), recordLocation.getDocId()); + numDeletedTTLKeysRemoved.getAndIncrement(); + } + } + }); + + // Update metrics + updatePrimaryKeyGauge(); + int numDeletedTTLKeys = numDeletedTTLKeysRemoved.get(); + if (numDeletedTTLKeys > 0) { + _logger.info("Deleted {} primary keys based on deletedKeysTTL", numDeletedTTLKeys); + _serverMetrics.addMeteredTableValue(_tableNameWithType, ServerMeter.DELETED_KEYS_TTL_PRIMARY_KEYS_REMOVED, + numDeletedTTLKeys); + } + } + + @Override + protected boolean doAddRecord(MutableSegment segment, RecordInfo recordInfo) { + AtomicBoolean isOutOfOrderRecord = new AtomicBoolean(false); + ThreadSafeMutableRoaringBitmap validDocIds = Objects.requireNonNull(segment.getValidDocIds()); + ThreadSafeMutableRoaringBitmap queryableDocIds = segment.getQueryableDocIds(); + int newDocId = recordInfo.getDocId(); + Comparable newComparisonValue = recordInfo.getComparisonValue(); + + // When TTL is enabled, update largestSeenComparisonValue when adding new record + if (_deletedKeysTTL > 0) { + double comparisonValue = ((Number) newComparisonValue).doubleValue(); + _largestSeenComparisonValue.getAndUpdate(v -> Math.max(v, comparisonValue)); + } + + _primaryKeyToRecordLocationMap.compute(HashUtils.hashPrimaryKey(recordInfo.getPrimaryKey(), _hashFunction), + (primaryKey, currentRecordLocation) -> { + if (currentRecordLocation != null) { + // Existing primary key + IndexSegment currentSegment = currentRecordLocation.getSegment(); + // Update the record location when the new comparison value is greater than or equal to the current value. + // Update the record location when there is a tie to keep the newer record. + if (newComparisonValue.compareTo(currentRecordLocation.getComparisonValue()) >= 0) { + int currentDocId = currentRecordLocation.getDocId(); + if (segment == currentSegment) { + replaceDocId(segment, validDocIds, queryableDocIds, currentDocId, newDocId, recordInfo); + return new RecordLocation(segment, newDocId, newComparisonValue, + currentRecordLocation.getDistinctSegmentCount()); + } else { + replaceDocId(segment, validDocIds, queryableDocIds, currentSegment, currentDocId, newDocId, recordInfo); + return new RecordLocation(segment, newDocId, newComparisonValue, + RecordLocation.incrementSegmentCount(currentRecordLocation.getDistinctSegmentCount())); + } + } else { + // Out-of-order record + handleOutOfOrderEvent(currentRecordLocation.getComparisonValue(), recordInfo.getComparisonValue()); + isOutOfOrderRecord.set(true); + if (segment == currentSegment) { + return currentRecordLocation; + } else { + return new RecordLocation(currentSegment, currentRecordLocation.getDocId(), + currentRecordLocation.getComparisonValue(), + _context.isDropOutOfOrderRecord() ? currentRecordLocation.getDistinctSegmentCount() + : RecordLocation.incrementSegmentCount(currentRecordLocation.getDistinctSegmentCount())); + } + } + } else { + // New primary key + addDocId(segment, validDocIds, queryableDocIds, newDocId, recordInfo); + return new RecordLocation(segment, newDocId, newComparisonValue, 1); + } + }); + + updatePrimaryKeyGauge(); + return !isOutOfOrderRecord.get(); + } + + @Override + protected void removeSegment(IndexSegment segment, MutableRoaringBitmap validDocIds) { + } + + @Override + protected GenericRow doUpdateRecord(GenericRow record, RecordInfo recordInfo) { + assert _partialUpsertHandler != null; + _primaryKeyToRecordLocationMap.computeIfPresent(HashUtils.hashPrimaryKey(recordInfo.getPrimaryKey(), _hashFunction), + (pk, recordLocation) -> { + // Read the previous record if the following conditions are met: + // - New record is not a DELETE record + // - New record is not out-of-order + // - Previous record is not deleted + if (!recordInfo.isDeleteRecord() + && recordInfo.getComparisonValue().compareTo(recordLocation.getComparisonValue()) >= 0) { + IndexSegment currentSegment = recordLocation.getSegment(); + ThreadSafeMutableRoaringBitmap currentQueryableDocIds = currentSegment.getQueryableDocIds(); + int currentDocId = recordLocation.getDocId(); + if (currentQueryableDocIds == null || currentQueryableDocIds.contains(currentDocId)) { + _reusePreviousRow.init(currentSegment, currentDocId); + _partialUpsertHandler.merge(_reusePreviousRow, record, _reuseMergeResultHolder); + _reuseMergeResultHolder.clear(); + } + } + return recordLocation; + }); + return record; + } + + @VisibleForTesting + static class RecordLocation { + private final IndexSegment _segment; + private final int _docId; + private final Comparable _comparisonValue; + // The number of distinct segments in which the record is present. If this count is less than or equal to 1, + // we proceed to remove the record from the primary hashmap during the deletedKeysTTL process. + private final int _distinctSegmentCount; + + public RecordLocation(IndexSegment indexSegment, int docId, Comparable comparisonValue, int distinctSegmentCount) { + _segment = indexSegment; + _docId = docId; + _comparisonValue = comparisonValue; + _distinctSegmentCount = distinctSegmentCount; + } + + public static int incrementSegmentCount(int count) { + return count + 1; + } + + public static int decrementSegmentCount(int count) { + return count - 1; + } Review Comment: can we do it in a follow-up? initially this will help me in debugging if we are missing out on any edge cases while doing addition / subtraction? 😅 ########## pinot-spi/src/main/java/org/apache/pinot/spi/config/table/UpsertConfig.java: ########## @@ -79,6 +79,9 @@ public enum ConsistencyMode { @JsonPropertyDescription("Whether to preload segments for fast upsert metadata recovery") private boolean _enablePreload; + @JsonPropertyDescription("If we are using deletion + compaction we need to enable this for data consistency") Review Comment: Updated! -- This is an automated message from the Apache Git Service. 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