| /** |
| * 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.controller.helix.core.assignment.segment; |
| |
| import com.google.common.base.Preconditions; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.TreeMap; |
| import javax.annotation.Nullable; |
| import org.apache.commons.collections.CollectionUtils; |
| import org.apache.commons.configuration.Configuration; |
| import org.apache.commons.lang3.tuple.Pair; |
| import org.apache.pinot.common.assignment.InstancePartitions; |
| import org.apache.pinot.common.tier.Tier; |
| import org.apache.pinot.controller.helix.core.assignment.segment.strategy.SegmentAssignmentStrategy; |
| import org.apache.pinot.controller.helix.core.assignment.segment.strategy.SegmentAssignmentStrategyFactory; |
| import org.apache.pinot.spi.config.table.TableConfig; |
| import org.apache.pinot.spi.config.table.assignment.InstancePartitionsType; |
| import org.apache.pinot.spi.utils.CommonConstants.Helix.StateModel.SegmentStateModel; |
| import org.apache.pinot.spi.utils.RebalanceConfigConstants; |
| |
| |
| /** |
| * Segment assignment for LLC real-time table. |
| * <ul> |
| * <li> |
| * For the CONSUMING segments, it is very similar to replica-group based segment assignment with the following |
| * differences: |
| * <ul> |
| * <li> |
| * 1. Within a replica-group, all segments of the same stream partition are always assigned to the same exactly |
| * one instance, and because of that we can directly assign or rebalance the CONSUMING segments to the instances |
| * based on the partition id |
| * </li> |
| * <li> |
| * 2. If no explicit partition is configured in the instance partitions, partition id for an instance is derived |
| * from the index of the instance (within the replica-group for replica-group based assignment) |
| * </li> |
| * </ul> |
| * </li> |
| * <li> |
| * For the COMPLETED segments: |
| * <ul> |
| * <li> |
| * If COMPLETED instance partitions are provided, reassign COMPLETED segments the same way as |
| * {@link OfflineSegmentAssignment} to relocate COMPLETED segments and offload them from CONSUMING instances to |
| * COMPLETED instances |
| * </li> |
| * <li> |
| * If COMPLETED instance partitions are not provided, reassign COMPLETED segments the same way as CONSUMING |
| * segments with CONSUMING instance partitions to ensure COMPLETED segments are served by the correct instances |
| * when instances for the table has been changed. |
| * </li> |
| * </ul> |
| * </li> |
| * </ul> |
| */ |
| public class RealtimeSegmentAssignment extends BaseSegmentAssignment { |
| |
| @Override |
| protected int getReplication(TableConfig tableConfig) { |
| return tableConfig.getValidationConfig().getReplicasPerPartitionNumber(); |
| } |
| |
| @Override |
| public List<String> assignSegment(String segmentName, Map<String, Map<String, String>> currentAssignment, |
| Map<InstancePartitionsType, InstancePartitions> instancePartitionsMap) { |
| Preconditions.checkState(instancePartitionsMap.size() == 1, "One instance partition type should be provided"); |
| Map.Entry<InstancePartitionsType, InstancePartitions> typeToInstancePartitions = |
| instancePartitionsMap.entrySet().iterator().next(); |
| InstancePartitionsType instancePartitionsType = typeToInstancePartitions.getKey(); |
| InstancePartitions instancePartitions = typeToInstancePartitions.getValue(); |
| _logger.info("Assigning segment: {} with instance partitions: {} for table: {}", segmentName, instancePartitions, |
| _tableNameWithType); |
| |
| // TODO: remove this check after we also refactor consuming segments assignment strategy |
| // See https://github.com/apache/pinot/issues/9047 |
| List<String> instancesAssigned; |
| if (instancePartitionsType == InstancePartitionsType.COMPLETED) { |
| // Gets Segment assignment strategy for instance partitions |
| SegmentAssignmentStrategy segmentAssignmentStrategy = SegmentAssignmentStrategyFactory |
| .getSegmentAssignmentStrategy(_helixManager, _tableConfig, instancePartitionsType.toString(), |
| instancePartitions); |
| instancesAssigned = segmentAssignmentStrategy |
| .assignSegment(segmentName, currentAssignment, instancePartitions, InstancePartitionsType.COMPLETED); |
| } else { |
| instancesAssigned = assignConsumingSegment(segmentName, instancePartitions); |
| } |
| _logger.info("Assigned segment: {} to instances: {} for table: {}", segmentName, instancesAssigned, |
| _tableNameWithType); |
| return instancesAssigned; |
| } |
| |
| /** |
| * Helper method to assign instances for CONSUMING segment based on the segment partition id and instance partitions. |
| */ |
| private List<String> assignConsumingSegment(String segmentName, InstancePartitions instancePartitions) { |
| int segmentPartitionId = SegmentAssignmentUtils |
| .getRealtimeSegmentPartitionId(segmentName, _tableNameWithType, _helixManager, _partitionColumn); |
| int numReplicaGroups = instancePartitions.getNumReplicaGroups(); |
| int numPartitions = instancePartitions.getNumPartitions(); |
| |
| if (numReplicaGroups == 1 && numPartitions == 1) { |
| // Non-replica-group based assignment: |
| // Uniformly spray the partitions and replicas across the instances. |
| // E.g. (6 instances, 3 partitions, 4 replicas) |
| // "0_0": [i0, i1, i2, i3, i4, i5 ] |
| // p0r0 p0r1 p0r2 p1r3 p1r0 p1r1 |
| // p1r2 p1r3 p2r0 p2r1 p2r2 p2r3 |
| |
| List<String> instances = |
| SegmentAssignmentUtils.getInstancesForNonReplicaGroupBasedAssignment(instancePartitions, _replication); |
| int numInstances = instances.size(); |
| List<String> instancesAssigned = new ArrayList<>(_replication); |
| for (int replicaId = 0; replicaId < _replication; replicaId++) { |
| int instanceIndex = (segmentPartitionId * _replication + replicaId) % numInstances; |
| instancesAssigned.add(instances.get(instanceIndex)); |
| } |
| return instancesAssigned; |
| } else { |
| // Replica-group based assignment |
| // TODO: Refactor check replication this for segment assignment strategy in follow up PR |
| // See https://github.com/apache/pinot/issues/9047 |
| if (numReplicaGroups != _replication) { |
| _logger.warn( |
| "Number of replica-groups in instance partitions {}: {} does not match replication in table config: {} for " |
| + "table: {}, using: {}", instancePartitions.getInstancePartitionsName(), numReplicaGroups, |
| _replication, _tableNameWithType, numReplicaGroups); |
| } |
| List<String> instancesAssigned = new ArrayList<>(numReplicaGroups); |
| |
| if (numPartitions == 1) { |
| // Implicit partition: |
| // Within a replica-group, uniformly spray the partitions across the instances. |
| // E.g. (within a replica-group, 3 instances, 6 partitions) |
| // "0_0": [i0, i1, i2] |
| // p0 p1 p2 |
| // p3 p4 p5 |
| |
| for (int replicaGroupId = 0; replicaGroupId < numReplicaGroups; replicaGroupId++) { |
| List<String> instances = instancePartitions.getInstances(0, replicaGroupId); |
| instancesAssigned.add(instances.get(segmentPartitionId % instances.size())); |
| } |
| } else { |
| // Explicit partition: |
| // Assign segment to the first instance within the partition. |
| |
| for (int replicaGroupId = 0; replicaGroupId < numReplicaGroups; replicaGroupId++) { |
| int partitionId = segmentPartitionId % numPartitions; |
| instancesAssigned.add(instancePartitions.getInstances(partitionId, replicaGroupId).get(0)); |
| } |
| } |
| |
| return instancesAssigned; |
| } |
| } |
| |
| @Override |
| public Map<String, Map<String, String>> rebalanceTable(Map<String, Map<String, String>> currentAssignment, |
| Map<InstancePartitionsType, InstancePartitions> instancePartitionsMap, @Nullable List<Tier> sortedTiers, |
| @Nullable Map<String, InstancePartitions> tierInstancePartitionsMap, Configuration config) { |
| InstancePartitions completedInstancePartitions = instancePartitionsMap.get(InstancePartitionsType.COMPLETED); |
| InstancePartitions consumingInstancePartitions = instancePartitionsMap.get(InstancePartitionsType.CONSUMING); |
| Preconditions |
| .checkState(consumingInstancePartitions != null, "Failed to find CONSUMING instance partitions for table: %s", |
| _tableNameWithType); |
| boolean includeConsuming = config |
| .getBoolean(RebalanceConfigConstants.INCLUDE_CONSUMING, RebalanceConfigConstants.DEFAULT_INCLUDE_CONSUMING); |
| boolean bootstrap = |
| config.getBoolean(RebalanceConfigConstants.BOOTSTRAP, RebalanceConfigConstants.DEFAULT_BOOTSTRAP); |
| |
| // TODO: remove this check after we also refactor consuming segments assignment strategy |
| // See https://github.com/apache/pinot/issues/9047 |
| SegmentAssignmentStrategy segmentAssignmentStrategy = null; |
| if (completedInstancePartitions != null) { |
| // Gets Segment assignment strategy for instance partitions |
| segmentAssignmentStrategy = SegmentAssignmentStrategyFactory |
| .getSegmentAssignmentStrategy(_helixManager, _tableConfig, InstancePartitionsType.COMPLETED.toString(), |
| completedInstancePartitions); |
| } |
| |
| // Rebalance tiers first |
| Pair<List<Map<String, Map<String, String>>>, Map<String, Map<String, String>>> pair = |
| rebalanceTiers(currentAssignment, sortedTiers, tierInstancePartitionsMap, bootstrap, segmentAssignmentStrategy, |
| InstancePartitionsType.COMPLETED); |
| |
| List<Map<String, Map<String, String>>> newTierAssignments = pair.getLeft(); |
| Map<String, Map<String, String>> nonTierAssignment = pair.getRight(); |
| |
| _logger.info("Rebalancing table: {} with COMPLETED instance partitions: {}, CONSUMING instance partitions: {}, " |
| + "includeConsuming: {}, bootstrap: {}", _tableNameWithType, completedInstancePartitions, |
| consumingInstancePartitions, includeConsuming, bootstrap); |
| |
| SegmentAssignmentUtils.CompletedConsumingOfflineSegmentAssignment completedConsumingOfflineSegmentAssignment = |
| new SegmentAssignmentUtils.CompletedConsumingOfflineSegmentAssignment(nonTierAssignment); |
| Map<String, Map<String, String>> newAssignment; |
| |
| // Reassign COMPLETED segments first |
| Map<String, Map<String, String>> completedSegmentAssignment = |
| completedConsumingOfflineSegmentAssignment.getCompletedSegmentAssignment(); |
| if (completedInstancePartitions != null) { |
| // When COMPLETED instance partitions are provided, reassign COMPLETED segments in a balanced way (relocate |
| // COMPLETED segments to offload them from CONSUMING instances to COMPLETED instances) |
| _logger |
| .info("Reassigning COMPLETED segments with COMPLETED instance partitions for table: {}", _tableNameWithType); |
| newAssignment = reassignSegments(InstancePartitionsType.COMPLETED.toString(), completedSegmentAssignment, |
| completedInstancePartitions, bootstrap, segmentAssignmentStrategy, InstancePartitionsType.COMPLETED); |
| } else { |
| // When COMPLETED instance partitions are not provided, reassign COMPLETED segments the same way as CONSUMING |
| // segments with CONSUMING instance partitions (ensure COMPLETED segments are served by the correct instances when |
| // instances for the table has been changed) |
| _logger.info( |
| "No COMPLETED instance partitions found, reassigning COMPLETED segments the same way as CONSUMING segments " |
| + "with CONSUMING instance partitions for table: {}", _tableNameWithType); |
| |
| newAssignment = new TreeMap<>(); |
| for (String segmentName : completedSegmentAssignment.keySet()) { |
| List<String> instancesAssigned = assignConsumingSegment(segmentName, consumingInstancePartitions); |
| Map<String, String> instanceStateMap = |
| SegmentAssignmentUtils.getInstanceStateMap(instancesAssigned, SegmentStateModel.ONLINE); |
| newAssignment.put(segmentName, instanceStateMap); |
| } |
| } |
| |
| // Reassign CONSUMING segments if configured |
| Map<String, Map<String, String>> consumingSegmentAssignment = |
| completedConsumingOfflineSegmentAssignment.getConsumingSegmentAssignment(); |
| if (includeConsuming) { |
| _logger |
| .info("Reassigning CONSUMING segments with CONSUMING instance partitions for table: {}", _tableNameWithType); |
| |
| for (String segmentName : consumingSegmentAssignment.keySet()) { |
| List<String> instancesAssigned = assignConsumingSegment(segmentName, consumingInstancePartitions); |
| Map<String, String> instanceStateMap = |
| SegmentAssignmentUtils.getInstanceStateMap(instancesAssigned, SegmentStateModel.CONSUMING); |
| newAssignment.put(segmentName, instanceStateMap); |
| } |
| } else { |
| newAssignment.putAll(consumingSegmentAssignment); |
| } |
| |
| // Keep the OFFLINE segments not moved, and RealtimeSegmentValidationManager will periodically detect the OFFLINE |
| // segments and re-assign them |
| newAssignment.putAll(completedConsumingOfflineSegmentAssignment.getOfflineSegmentAssignment()); |
| |
| // Add tier assignments, if available |
| if (CollectionUtils.isNotEmpty(newTierAssignments)) { |
| newTierAssignments.forEach(newAssignment::putAll); |
| } |
| |
| _logger.info("Rebalanced table: {}, number of segments to be moved to each instance: {}", _tableNameWithType, |
| SegmentAssignmentUtils.getNumSegmentsToBeMovedPerInstance(currentAssignment, newAssignment)); |
| return newAssignment; |
| } |
| } |
