OneSizeFitsQuorum commented on code in PR #15022: URL: https://github.com/apache/iotdb/pull/15022#discussion_r1985084563
########## iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/manager/load/balancer/region/PartiteGraphPlacementDestNodeSelector.java: ########## @@ -0,0 +1,166 @@ +/* + * 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.iotdb.confignode.manager.load.balancer.region; + +import org.apache.iotdb.common.rpc.thrift.TConsensusGroupId; +import org.apache.iotdb.common.rpc.thrift.TDataNodeConfiguration; +import org.apache.iotdb.common.rpc.thrift.TDataNodeLocation; +import org.apache.iotdb.common.rpc.thrift.TRegionReplicaSet; +import org.apache.iotdb.confignode.manager.load.balancer.region.GreedyRegionGroupAllocator.DataNodeEntry; + +import org.apache.tsfile.utils.Pair; + +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Collections; +import java.util.List; +import java.util.Map; +import java.util.Set; +import java.util.TreeMap; +import java.util.stream.Collectors; + +public class PartiteGraphPlacementDestNodeSelector implements IDestNodeSelector { + private int replicationFactor; + + private int dataNodeNum; + // The number of allocated Regions in each DataNode + private int[] regionCounter; + // The number of edges in current cluster + private int[][] combinationCounter; + private Map<Integer, Integer> fakeToRealIdMap; + private Map<Integer, Integer> realToFakeIdMap; + + private Set<Integer> remainDataNodesFakeId; + + // Pair<combinationSum, RegionSum> + Pair<Integer, Integer> bestValue; + + private Integer targetDataNode = -1; + + @Override + public TDataNodeConfiguration selectDestDataNode( + Map<Integer, TDataNodeConfiguration> availableDataNodeMap, + Map<Integer, Double> freeDiskSpaceMap, + List<TRegionReplicaSet> allocatedRegionGroups, + List<TRegionReplicaSet> databaseAllocatedRegionGroups, + int replicationFactor, + TConsensusGroupId consensusGroupId, + TRegionReplicaSet remainReplicaSet) { + prepare(replicationFactor, availableDataNodeMap, allocatedRegionGroups, remainReplicaSet); + + searchTargetDataNode(freeDiskSpaceMap); + + return availableDataNodeMap.get(fakeToRealIdMap.get(targetDataNode)); + } + + private void prepare( + int replicationFactor, + Map<Integer, TDataNodeConfiguration> availableDataNodeMap, + List<TRegionReplicaSet> allocatedRegionGroups, + TRegionReplicaSet remainReplicaSet) { + this.replicationFactor = replicationFactor; + this.fakeToRealIdMap = new TreeMap<>(); + this.realToFakeIdMap = new TreeMap<>(); + this.dataNodeNum = availableDataNodeMap.size(); + List<Integer> dataNodeIdList = + availableDataNodeMap.values().stream() + .map(c -> c.getLocation().getDataNodeId()) + .collect(Collectors.toList()); + for (int i = 0; i < dataNodeNum; i++) { + fakeToRealIdMap.put(i, dataNodeIdList.get(i)); + realToFakeIdMap.put(dataNodeIdList.get(i), i); + } + + remainDataNodesFakeId = + remainReplicaSet.dataNodeLocations.stream() + .map(TDataNodeLocation::getDataNodeId) + .map(realToFakeIdMap::get) + .collect(Collectors.toSet()); + + // Compute regionCounter and combinationCounter + this.regionCounter = new int[dataNodeNum]; + Arrays.fill(regionCounter, 0); + this.combinationCounter = new int[dataNodeNum][dataNodeNum]; + for (int i = 0; i < dataNodeNum; i++) { + Arrays.fill(combinationCounter[i], 0); + } + for (TRegionReplicaSet regionReplicaSet : allocatedRegionGroups) { + List<TDataNodeLocation> dataNodeLocations = regionReplicaSet.getDataNodeLocations(); + for (int i = 0; i < dataNodeLocations.size(); i++) { + int fakeIId = realToFakeIdMap.get(dataNodeLocations.get(i).getDataNodeId()); + regionCounter[fakeIId]++; + for (int j = i + 1; j < dataNodeLocations.size(); j++) { + int fakeJId = realToFakeIdMap.get(dataNodeLocations.get(j).getDataNodeId()); + combinationCounter[fakeIId][fakeJId] = 1; + combinationCounter[fakeJId][fakeIId] = 1; + } + } + } + + this.bestValue = new Pair<>(Integer.MAX_VALUE, Integer.MAX_VALUE); + } + + private void searchTargetDataNode(Map<Integer, Double> freeDiskSpaceMap) { + List<DataNodeEntry> entryList = new ArrayList<>(); + + for (int i = 0; i < dataNodeNum; i++) { + if (remainDataNodesFakeId.contains(i)) { + continue; + } + entryList.add( + new DataNodeEntry(i, regionCounter[i], freeDiskSpaceMap.get(fakeToRealIdMap.get(i)))); + } + Collections.sort(entryList); + + int[] alternativeReplica = new int[replicationFactor]; + + int pos = 0; + for (Integer integer : remainDataNodesFakeId) { + alternativeReplica[pos] = integer; Review Comment: This is not a future work, currently we support extend region so that the number of replicas of regiongroup is not consistent with the configuration parameter. This feeling can be guarded a little more, because otherwise we could end up with an index out of bound error even during region migration if the number of replicas is not consistent -- 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]
