kfaraz commented on code in PR #19772: URL: https://github.com/apache/druid/pull/19772#discussion_r3727132434
########## indexing-service/src/main/java/org/apache/druid/indexing/overlord/SegmentStatusManager.java: ########## @@ -0,0 +1,254 @@ +/* + * 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.druid.indexing.overlord; + +import com.google.inject.Inject; +import org.apache.druid.common.utils.IdUtils; +import org.apache.druid.error.DruidException; +import org.apache.druid.error.InternalServerError; +import org.apache.druid.indexer.TaskStatus; +import org.apache.druid.indexing.common.TaskLock; +import org.apache.druid.indexing.common.TaskLockType; +import org.apache.druid.indexing.common.TaskToolbox; +import org.apache.druid.indexing.common.actions.TaskActionClient; +import org.apache.druid.indexing.common.actions.TaskActionClientFactory; +import org.apache.druid.indexing.common.actions.TimeChunkLockTryAcquireAction; +import org.apache.druid.indexing.common.task.AbstractFixedIntervalTask; +import org.apache.druid.indexing.common.task.Task; +import org.apache.druid.indexing.common.task.TaskMetrics; +import org.apache.druid.java.util.common.Intervals; +import org.apache.druid.java.util.common.JodaUtils; +import org.apache.druid.java.util.common.Stopwatch; +import org.apache.druid.java.util.common.logger.Logger; +import org.apache.druid.java.util.emitter.service.ServiceEmitter; +import org.apache.druid.java.util.emitter.service.ServiceMetricEvent; +import org.apache.druid.query.DruidMetrics; +import org.apache.druid.timeline.SegmentId; +import org.joda.time.Interval; + +import javax.annotation.Nullable; +import java.util.List; +import java.util.Map; +import java.util.Set; + +/** + * Performs updates on segments to change their "used" status in the metadata store. + * <p> + * Currently, this class exposes methods that are used to acquire an EXCLUSIVE + * lock while marking segments in an interval as "used". A similar restriction + * may be imposed on marking (non-overshadowed) segments as unused in the future. + * + * @see #markAsUsedWithExclusiveLock(String, Interval, UpdateOperation) + * Reasons for using EXCLUSIVE locks + */ +public class SegmentStatusManager +{ + private static final Logger log = new Logger(SegmentStatusManager.class); + private static final String TASK_TYPE_MARK_USED = "markSegmentAsUsed"; + + private final ServiceEmitter emitter; + private final GlobalTaskLockbox taskLockbox; + private final TaskActionClientFactory taskActionClientFactory; + private final IndexerMetadataStorageCoordinator storageCoordinator; + + @Inject + public SegmentStatusManager( + GlobalTaskLockbox taskLockbox, + IndexerMetadataStorageCoordinator storageCoordinator, + TaskActionClientFactory taskActionClientFactory, + ServiceEmitter emitter + ) + { + this.emitter = emitter; + this.taskLockbox = taskLockbox; + this.storageCoordinator = storageCoordinator; + this.taskActionClientFactory = taskActionClientFactory; + } + + /** + * Same as {@link IndexerMetadataStorageCoordinator#markAllNonOvershadowedSegmentsAsUsed(String)} + * but with an EXCLUSIVE lock. + */ + public int markAllNonOvershadowedSegmentsAsUsed(String dataSource) + { + return markAsUsedWithExclusiveLock( + dataSource, + Intervals.ETERNITY, + () -> storageCoordinator.markAllNonOvershadowedSegmentsAsUsed(dataSource) + ); + } + + /** + * Same as {@link IndexerMetadataStorageCoordinator#markNonOvershadowedSegmentsAsUsed(String, Interval, List)} + * but with an EXCLUSIVE lock. + */ + public int markNonOvershadowedSegmentsAsUsed( + String dataSource, + Interval interval, + @Nullable List<String> versions + ) + { + return markAsUsedWithExclusiveLock( + dataSource, + interval, + () -> storageCoordinator.markNonOvershadowedSegmentsAsUsed(dataSource, interval, versions) + ); + } + + /** + * Same as {@link IndexerMetadataStorageCoordinator#markNonOvershadowedSegmentsAsUsed(String, Set)} + * but with an EXCLUSIVE lock. + */ + public int markNonOvershadowedSegmentsAsUsed(String dataSource, Set<SegmentId> segmentIds) + { + return markAsUsedWithExclusiveLock( + dataSource, + JodaUtils.umbrellaInterval(segmentIds.stream().map(SegmentId::getInterval).toList()), + () -> storageCoordinator.markNonOvershadowedSegmentsAsUsed(dataSource, segmentIds) + ); + } + + /** + * Same as {@link IndexerMetadataStorageCoordinator#markSegmentAsUsed(SegmentId)} + * but with an EXCLUSIVE lock. + */ + public int markSegmentAsUsed(SegmentId segmentId) + { + return markAsUsedWithExclusiveLock( + segmentId.getDataSource(), + segmentId.getInterval(), + () -> storageCoordinator.markSegmentAsUsed(segmentId) ? 1 : 0 + ); + } + + /** + * Mark segments for a datasource-interval as used while holding an EXCLUSIVE + * lock. Most APIs mark non-overshadowed segments as used. So, as soon as they + * are updated, they would become visible to other metadata operations. This + * may cause concurrent append jobs to see an inconsistent view of existing + * segments during their lifecycle. It may also cause a concurrent kill task + * to accidentally delete files of a segment that has just been marked as used + * and then upgraded. + * + * @return Number of segments updated. + */ + private int markAsUsedWithExclusiveLock(String dataSource, Interval interval, UpdateOperation operation) + { + final Stopwatch taskRunTime = Stopwatch.createStarted(); + + final String taskId = IdUtils.newTaskId(TASK_TYPE_MARK_USED, dataSource, interval); + final ExclusiveIntervalDummyTask dummyTask + = new ExclusiveIntervalDummyTask(taskId, dataSource, interval); + + final TaskActionClient taskActionClient = taskActionClientFactory.create(dummyTask); + + final ServiceMetricEvent.Builder metricBuilder = new ServiceMetricEvent.Builder(); + metricBuilder.setDimension(DruidMetrics.INTERVAL, interval); + metricBuilder.setDimension(DruidMetrics.DATASOURCE, dataSource); + + try { + // Acquire lock on the interval before performing the update operation + taskLockbox.add(dummyTask); Review Comment: Thanks for calling this out, let me evaluate this further and add some validations. If it still doesn't seem viable, I will try an alternative. (I suppose we could always remove that check from `TaskLockbox`, as the `Task` object fetched from storage is not really used for anything else). -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
