imply-cheddar commented on code in PR #13197: URL: https://github.com/apache/druid/pull/13197#discussion_r997793124
########## server/src/main/java/org/apache/druid/server/coordinator/SegmentStateManager.java: ########## @@ -0,0 +1,261 @@ +/* + * 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.server.coordinator; + +import com.google.inject.Inject; +import org.apache.druid.client.ServerInventoryView; +import org.apache.druid.java.util.emitter.EmittingLogger; +import org.apache.druid.metadata.SegmentsMetadataManager; +import org.apache.druid.timeline.DataSegment; + +import java.util.Collections; +import java.util.HashSet; +import java.util.Map; +import java.util.Set; +import java.util.concurrent.ConcurrentHashMap; + +/** + * Manages state of segments being loaded. + */ +public class SegmentStateManager +{ + private static final EmittingLogger log = new EmittingLogger(SegmentStateManager.class); + + private final LoadQueueTaskMaster taskMaster; + private final ServerInventoryView serverInventoryView; + private final SegmentsMetadataManager segmentsMetadataManager; + + private final ConcurrentHashMap<String, TierLoadingState> currentlyMovingSegments = + new ConcurrentHashMap<>(); + private final ConcurrentHashMap<String, TierLoadingState> currentlyReplicatingSegments + = new ConcurrentHashMap<>(); + + @Inject + public SegmentStateManager( + ServerInventoryView serverInventoryView, + SegmentsMetadataManager segmentsMetadataManager, + LoadQueueTaskMaster taskMaster + ) + { + this.serverInventoryView = serverInventoryView; + this.segmentsMetadataManager = segmentsMetadataManager; + this.taskMaster = taskMaster; + } + + /** + * Queues load of a replica of the segment on the given server. + */ + public boolean loadSegment( + DataSegment segment, + ServerHolder server, + boolean isPrimary, + ReplicationThrottler throttler + ) + { + final String tier = server.getServer().getTier(); + final LoadPeonCallback callback; + if (isPrimary) { + // Primary replicas are not subject to throttling + callback = null; Review Comment: What's the definition of "isPrimary"? There really isn't a notion of "primary" or "secondary" replication, at least there shouldn't be. The only semantic difference that should exist is 1) If the data is not available at all inside of the tier -> get the data loaded as fast as humanly possibly 2) If the data is available somewhere inside of the tier -> throttle the loading so that there is capacity in the cluster for other activities as well as under the assumption that this usually happens due to a failure and the node could just be flapping. ########## server/src/main/java/org/apache/druid/server/coordinator/SegmentStateManager.java: ########## @@ -0,0 +1,261 @@ +/* + * 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.server.coordinator; + +import com.google.inject.Inject; +import org.apache.druid.client.ServerInventoryView; +import org.apache.druid.java.util.emitter.EmittingLogger; +import org.apache.druid.metadata.SegmentsMetadataManager; +import org.apache.druid.timeline.DataSegment; + +import java.util.Collections; +import java.util.HashSet; +import java.util.Map; +import java.util.Set; +import java.util.concurrent.ConcurrentHashMap; + +/** + * Manages state of segments being loaded. + */ +public class SegmentStateManager +{ + private static final EmittingLogger log = new EmittingLogger(SegmentStateManager.class); + + private final LoadQueueTaskMaster taskMaster; + private final ServerInventoryView serverInventoryView; + private final SegmentsMetadataManager segmentsMetadataManager; + + private final ConcurrentHashMap<String, TierLoadingState> currentlyMovingSegments = + new ConcurrentHashMap<>(); + private final ConcurrentHashMap<String, TierLoadingState> currentlyReplicatingSegments + = new ConcurrentHashMap<>(); + + @Inject + public SegmentStateManager( + ServerInventoryView serverInventoryView, + SegmentsMetadataManager segmentsMetadataManager, + LoadQueueTaskMaster taskMaster + ) + { + this.serverInventoryView = serverInventoryView; + this.segmentsMetadataManager = segmentsMetadataManager; + this.taskMaster = taskMaster; + } + + /** + * Queues load of a replica of the segment on the given server. + */ + public boolean loadSegment( + DataSegment segment, + ServerHolder server, + boolean isPrimary, + ReplicationThrottler throttler + ) + { + final String tier = server.getServer().getTier(); + final LoadPeonCallback callback; + if (isPrimary) { + // Primary replicas are not subject to throttling + callback = null; + } else if (canLoadReplica(tier, throttler)) { + throttler.incrementAssignedReplicas(tier); + + final TierLoadingState replicatingInTier = currentlyReplicatingSegments + .computeIfAbsent(tier, t -> new TierLoadingState(throttler.getMaxLifetime())); + replicatingInTier.addSegment(segment.getId(), server.getServer().getHost()); + callback = success -> replicatingInTier.removeSegment(segment.getId()); + } else { + throttler.incrementThrottledReplicas(tier); + return false; + } + + try { + if (!server.startOperation(segment, SegmentState.LOADING)) { + return false; + } + + server.getPeon().loadSegment( + segment, + isPrimary ? SegmentAction.LOAD_AS_PRIMARY : SegmentAction.LOAD_AS_REPLICA, Review Comment: Let's please kill this false notion of primary/replica and use words that actually align with the semantics that should exist. ########## server/src/main/java/org/apache/druid/server/coordinator/SegmentStateManager.java: ########## @@ -0,0 +1,261 @@ +/* + * 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.server.coordinator; + +import com.google.inject.Inject; +import org.apache.druid.client.ServerInventoryView; +import org.apache.druid.java.util.emitter.EmittingLogger; +import org.apache.druid.metadata.SegmentsMetadataManager; +import org.apache.druid.timeline.DataSegment; + +import java.util.Collections; +import java.util.HashSet; +import java.util.Map; +import java.util.Set; +import java.util.concurrent.ConcurrentHashMap; + +/** + * Manages state of segments being loaded. + */ +public class SegmentStateManager +{ + private static final EmittingLogger log = new EmittingLogger(SegmentStateManager.class); + + private final LoadQueueTaskMaster taskMaster; + private final ServerInventoryView serverInventoryView; + private final SegmentsMetadataManager segmentsMetadataManager; + + private final ConcurrentHashMap<String, TierLoadingState> currentlyMovingSegments = + new ConcurrentHashMap<>(); + private final ConcurrentHashMap<String, TierLoadingState> currentlyReplicatingSegments + = new ConcurrentHashMap<>(); + + @Inject + public SegmentStateManager( + ServerInventoryView serverInventoryView, + SegmentsMetadataManager segmentsMetadataManager, + LoadQueueTaskMaster taskMaster + ) + { + this.serverInventoryView = serverInventoryView; + this.segmentsMetadataManager = segmentsMetadataManager; + this.taskMaster = taskMaster; + } + + /** + * Queues load of a replica of the segment on the given server. + */ + public boolean loadSegment( + DataSegment segment, + ServerHolder server, + boolean isPrimary, + ReplicationThrottler throttler + ) + { + final String tier = server.getServer().getTier(); + final LoadPeonCallback callback; + if (isPrimary) { + // Primary replicas are not subject to throttling + callback = null; + } else if (canLoadReplica(tier, throttler)) { + throttler.incrementAssignedReplicas(tier); + + final TierLoadingState replicatingInTier = currentlyReplicatingSegments + .computeIfAbsent(tier, t -> new TierLoadingState(throttler.getMaxLifetime())); + replicatingInTier.addSegment(segment.getId(), server.getServer().getHost()); + callback = success -> replicatingInTier.removeSegment(segment.getId()); + } else { + throttler.incrementThrottledReplicas(tier); + return false; + } + + try { + if (!server.startOperation(segment, SegmentState.LOADING)) { + return false; + } + + server.getPeon().loadSegment( + segment, + isPrimary ? SegmentAction.LOAD_AS_PRIMARY : SegmentAction.LOAD_AS_REPLICA, + callback + ); + return true; + } + catch (Exception e) { + server.cancelOperation(segment, SegmentState.LOADING); + return false; + } + } + + public boolean dropSegment(DataSegment segment, ServerHolder server) + { + try { + if (!server.startOperation(segment, SegmentState.DROPPING)) { + return false; + } + + server.getPeon().dropSegment(segment, null); + return true; + } + catch (Exception e) { + server.cancelOperation(segment, SegmentState.DROPPING); + return false; + } + } + + public boolean moveSegment( + DataSegment segment, + ServerHolder fromServer, + ServerHolder toServer, + int maxLifetimeInBalancingQueue + ) + { + final TierLoadingState segmentsMovingInTier = currentlyMovingSegments.computeIfAbsent( + toServer.getServer().getTier(), + t -> new TierLoadingState(maxLifetimeInBalancingQueue) + ); + final LoadQueuePeon fromServerPeon = fromServer.getPeon(); + final LoadPeonCallback moveFinishCallback = success -> { + fromServerPeon.unmarkSegmentToDrop(segment); + segmentsMovingInTier.removeSegment(segment.getId()); + }; + + // mark segment to drop before it is actually loaded on server + // to be able to account for this information in BalancerStrategy immediately + toServer.startOperation(segment, SegmentState.MOVING_TO); + fromServerPeon.markSegmentToDrop(segment); + segmentsMovingInTier.addSegment(segment.getId(), fromServer.getServer().getHost()); + + final LoadQueuePeon toServerPeon = toServer.getPeon(); + final String toServerName = toServer.getServer().getName(); + try { + toServerPeon.loadSegment( + segment, + SegmentAction.MOVE_TO, + success -> { + // Drop segment only if: + // (1) segment load was successful on toServer + // AND (2) segment not already queued for drop on fromServer + // AND (3a) loading is http-based + // OR (3b) inventory shows segment loaded on toServer + + // Do not check the inventory with http loading as the HTTP + // response is enough to determine load success or failure + if (success + && !fromServerPeon.getSegmentsToDrop().contains(segment) + && (taskMaster.isHttpLoading() + || serverInventoryView.isSegmentLoadedByServer(toServerName, segment))) { + fromServerPeon.dropSegment(segment, moveFinishCallback); + } else { + moveFinishCallback.execute(success); + } + } + ); + } + catch (Exception e) { + toServer.cancelOperation(segment, SegmentState.MOVING_TO); + moveFinishCallback.execute(false); + throw new RuntimeException(e); + } + + return true; + } + + /** + * Marks the given segment as unused. + */ + public boolean deleteSegment(DataSegment segment) + { + return segmentsMetadataManager.markSegmentAsUnused(segment.getId()); + } + + /** + * Cancels the segment operation being performed on a server if the actual + * state of the segment on the server matches the given currentState. + */ + public boolean cancelOperation( + SegmentState currentState, + DataSegment segment, + ServerHolder server + ) + { + if (!server.cancelOperation(segment, currentState)) { + return false; + } + + final LoadQueuePeon peon = server.getPeon(); + switch (currentState) { + case DROPPING: + return peon.cancelDrop(segment); + case MOVING_TO: + case LOADING: + return peon.cancelLoad(segment); + default: + return false; + } + } + + /** + * Reduces the lifetimes of the segments currently being moved in all the tiers, + * and returns a map from tier names to the corresponding state. + */ + public Map<String, TierLoadingState> reduceLifetimesOfMovingSegments() + { + return reduceLifetimesAndCreateCopy(currentlyMovingSegments); + } + + /** + * Reduces the lifetimes of the segments currently being replicated in the tiers, + * and returns a map from tier names to the corresponding state. + */ + public Map<String, TierLoadingState> reduceLifetimesOfReplicatingSegments() + { + return reduceLifetimesAndCreateCopy(currentlyReplicatingSegments); + } + + private Map<String, TierLoadingState> reduceLifetimesAndCreateCopy( + Map<String, TierLoadingState> inFlightSegments + ) + { + final Set<String> inactiveTiers = new HashSet<>(); + inFlightSegments.forEach((tier, holder) -> { + if (holder.getNumProcessingSegments() == 0) { + inactiveTiers.add(tier); + } + holder.reduceLifetime(); + }); + + // Reset state for inactive tiers + inactiveTiers.forEach(inFlightSegments::remove); + + return Collections.unmodifiableMap(inFlightSegments); + } + + private boolean canLoadReplica(String tier, ReplicationThrottler throttler) + { + if (!throttler.canAssignReplica(tier)) { + return false; + } + + TierLoadingState tierState = currentlyReplicatingSegments.get(tier); + return tierState == null || tierState.getNumProcessingSegments() < throttler.getReplicationThrottleLimit(); Review Comment: The latter part of this really "feels" like it's a throttling decision, but the throttler appears to not be making that decision? I don't know that I have a specific suggestion, just, it caught my eye as I read the code. ########## server/src/main/java/org/apache/druid/server/coordinator/SegmentStateManager.java: ########## @@ -0,0 +1,261 @@ +/* + * 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.server.coordinator; + +import com.google.inject.Inject; +import org.apache.druid.client.ServerInventoryView; +import org.apache.druid.java.util.emitter.EmittingLogger; +import org.apache.druid.metadata.SegmentsMetadataManager; +import org.apache.druid.timeline.DataSegment; + +import java.util.Collections; +import java.util.HashSet; +import java.util.Map; +import java.util.Set; +import java.util.concurrent.ConcurrentHashMap; + +/** + * Manages state of segments being loaded. + */ +public class SegmentStateManager +{ + private static final EmittingLogger log = new EmittingLogger(SegmentStateManager.class); + + private final LoadQueueTaskMaster taskMaster; + private final ServerInventoryView serverInventoryView; + private final SegmentsMetadataManager segmentsMetadataManager; + + private final ConcurrentHashMap<String, TierLoadingState> currentlyMovingSegments = + new ConcurrentHashMap<>(); + private final ConcurrentHashMap<String, TierLoadingState> currentlyReplicatingSegments + = new ConcurrentHashMap<>(); + + @Inject + public SegmentStateManager( + ServerInventoryView serverInventoryView, + SegmentsMetadataManager segmentsMetadataManager, + LoadQueueTaskMaster taskMaster + ) + { + this.serverInventoryView = serverInventoryView; + this.segmentsMetadataManager = segmentsMetadataManager; + this.taskMaster = taskMaster; + } + + /** + * Queues load of a replica of the segment on the given server. + */ + public boolean loadSegment( + DataSegment segment, + ServerHolder server, + boolean isPrimary, + ReplicationThrottler throttler + ) + { + final String tier = server.getServer().getTier(); + final LoadPeonCallback callback; + if (isPrimary) { + // Primary replicas are not subject to throttling + callback = null; + } else if (canLoadReplica(tier, throttler)) { + throttler.incrementAssignedReplicas(tier); + + final TierLoadingState replicatingInTier = currentlyReplicatingSegments + .computeIfAbsent(tier, t -> new TierLoadingState(throttler.getMaxLifetime())); + replicatingInTier.addSegment(segment.getId(), server.getServer().getHost()); + callback = success -> replicatingInTier.removeSegment(segment.getId()); Review Comment: Is this just internal bookkeeping? Or is it actually asking for the segment to be removed? If it's internal bookkeeping, `.markCompleted()` might be a better name. ########## server/src/main/java/org/apache/druid/server/coordinator/SegmentStateManager.java: ########## @@ -0,0 +1,261 @@ +/* + * 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.server.coordinator; + +import com.google.inject.Inject; +import org.apache.druid.client.ServerInventoryView; +import org.apache.druid.java.util.emitter.EmittingLogger; +import org.apache.druid.metadata.SegmentsMetadataManager; +import org.apache.druid.timeline.DataSegment; + +import java.util.Collections; +import java.util.HashSet; +import java.util.Map; +import java.util.Set; +import java.util.concurrent.ConcurrentHashMap; + +/** + * Manages state of segments being loaded. + */ +public class SegmentStateManager +{ + private static final EmittingLogger log = new EmittingLogger(SegmentStateManager.class); + + private final LoadQueueTaskMaster taskMaster; + private final ServerInventoryView serverInventoryView; + private final SegmentsMetadataManager segmentsMetadataManager; + + private final ConcurrentHashMap<String, TierLoadingState> currentlyMovingSegments = + new ConcurrentHashMap<>(); + private final ConcurrentHashMap<String, TierLoadingState> currentlyReplicatingSegments + = new ConcurrentHashMap<>(); + + @Inject + public SegmentStateManager( + ServerInventoryView serverInventoryView, + SegmentsMetadataManager segmentsMetadataManager, + LoadQueueTaskMaster taskMaster + ) + { + this.serverInventoryView = serverInventoryView; + this.segmentsMetadataManager = segmentsMetadataManager; + this.taskMaster = taskMaster; + } + + /** + * Queues load of a replica of the segment on the given server. + */ + public boolean loadSegment( + DataSegment segment, + ServerHolder server, + boolean isPrimary, + ReplicationThrottler throttler + ) + { + final String tier = server.getServer().getTier(); + final LoadPeonCallback callback; + if (isPrimary) { + // Primary replicas are not subject to throttling + callback = null; + } else if (canLoadReplica(tier, throttler)) { + throttler.incrementAssignedReplicas(tier); + + final TierLoadingState replicatingInTier = currentlyReplicatingSegments + .computeIfAbsent(tier, t -> new TierLoadingState(throttler.getMaxLifetime())); + replicatingInTier.addSegment(segment.getId(), server.getServer().getHost()); + callback = success -> replicatingInTier.removeSegment(segment.getId()); + } else { + throttler.incrementThrottledReplicas(tier); + return false; + } + + try { + if (!server.startOperation(segment, SegmentState.LOADING)) { + return false; + } + + server.getPeon().loadSegment( + segment, + isPrimary ? SegmentAction.LOAD_AS_PRIMARY : SegmentAction.LOAD_AS_REPLICA, + callback + ); + return true; + } + catch (Exception e) { + server.cancelOperation(segment, SegmentState.LOADING); + return false; + } + } + + public boolean dropSegment(DataSegment segment, ServerHolder server) + { + try { + if (!server.startOperation(segment, SegmentState.DROPPING)) { + return false; + } + + server.getPeon().dropSegment(segment, null); + return true; + } + catch (Exception e) { + server.cancelOperation(segment, SegmentState.DROPPING); + return false; + } + } + + public boolean moveSegment( + DataSegment segment, + ServerHolder fromServer, + ServerHolder toServer, + int maxLifetimeInBalancingQueue + ) + { + final TierLoadingState segmentsMovingInTier = currentlyMovingSegments.computeIfAbsent( + toServer.getServer().getTier(), + t -> new TierLoadingState(maxLifetimeInBalancingQueue) + ); + final LoadQueuePeon fromServerPeon = fromServer.getPeon(); + final LoadPeonCallback moveFinishCallback = success -> { + fromServerPeon.unmarkSegmentToDrop(segment); + segmentsMovingInTier.removeSegment(segment.getId()); + }; + + // mark segment to drop before it is actually loaded on server + // to be able to account for this information in BalancerStrategy immediately + toServer.startOperation(segment, SegmentState.MOVING_TO); + fromServerPeon.markSegmentToDrop(segment); + segmentsMovingInTier.addSegment(segment.getId(), fromServer.getServer().getHost()); + + final LoadQueuePeon toServerPeon = toServer.getPeon(); + final String toServerName = toServer.getServer().getName(); + try { + toServerPeon.loadSegment( + segment, + SegmentAction.MOVE_TO, + success -> { + // Drop segment only if: + // (1) segment load was successful on toServer + // AND (2) segment not already queued for drop on fromServer + // AND (3a) loading is http-based + // OR (3b) inventory shows segment loaded on toServer + + // Do not check the inventory with http loading as the HTTP + // response is enough to determine load success or failure + if (success Review Comment: If it wasn't successful, do we need to update the state that was set from the call to `fromServerPeon.markSegmentToDrop`? -- This is an automated message from the Apache Git Service. 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