vagetablechicken commented on a change in pull request #5010: URL: https://github.com/apache/incubator-doris/pull/5010#discussion_r539165745
########## File path: fe/fe-core/src/main/java/org/apache/doris/clone/PartitionRebalancer.java ########## @@ -0,0 +1,324 @@ +// 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.doris.clone; + +import com.google.common.base.Preconditions; +import com.google.common.collect.Lists; +import com.google.common.collect.Maps; +import com.google.common.collect.Ordering; +import com.google.common.collect.TreeMultimap; +import org.apache.doris.catalog.Replica; +import org.apache.doris.catalog.TabletInvertedIndex; +import org.apache.doris.catalog.TabletMeta; +import org.apache.doris.common.Config; +import org.apache.doris.common.Pair; +import org.apache.doris.system.SystemInfoService; +import org.apache.doris.thrift.TStorageMedium; +import org.apache.logging.log4j.LogManager; +import org.apache.logging.log4j.Logger; + +import java.util.List; +import java.util.Map; +import java.util.NavigableSet; +import java.util.Random; +import java.util.Set; +import java.util.concurrent.atomic.AtomicLong; +import java.util.stream.Collectors; + +public class PartitionRebalancer extends Rebalancer { + private static final Logger LOG = LogManager.getLogger(PartitionRebalancer.class); + + private final TwoDimensionalGreedyAlgo algo = new TwoDimensionalGreedyAlgo(); + protected final MovesInProgressCache movesInProgressCache = new MovesInProgressCache(); + + private final AtomicLong counterBalanceMoveCreated = new AtomicLong(0); + private final AtomicLong counterBalanceMoveSucceeded = new AtomicLong(0); + + public PartitionRebalancer(SystemInfoService infoService, TabletInvertedIndex invertedIndex) { + super(infoService, invertedIndex); + } + + @Override + protected List<TabletSchedCtx> selectAlternativeTabletsForCluster( + String clusterName, ClusterLoadStatistic clusterStat, TStorageMedium medium) { + MovesInProgressCache.Cell movesInProgress = movesInProgressCache.getCache(clusterName, medium); + Preconditions.checkNotNull(movesInProgress, "clusterStat is got from statisticMap, movesInProgressMap should have the same entry"); + + // iterating through cache.asMap().values() does not reset access time for the entries you retrieve. + List<ReplicaMove> movesInProgressList = movesInProgress.get().asMap().values() + .stream().map(p -> p.first).collect(Collectors.toList()); + List<Long> toDeleteKeys = Lists.newArrayList(); + + // The problematic movements will be found in buildClusterInfo(), so here is a simply move completion check + // of moves which have valid ToDeleteReplica. + List<ReplicaMove> movesNeedCheck = movesInProgress.get().asMap().values() + .stream().filter(p -> p.second != -1L).map(p -> p.first).collect(Collectors.toList()); + checkMovesCompleted(movesNeedCheck, toDeleteKeys); + + ClusterBalanceInfo clusterBalanceInfo = new ClusterBalanceInfo(); + // We should assume the in-progress moves have been succeeded to avoid producing the same moves. + // Apply in-progress moves to current cluster stats, use TwoDimensionalGreedyAlgo.ApplyMove for simplicity. + if (!buildClusterInfo(clusterStat, medium, movesInProgressList, clusterBalanceInfo, toDeleteKeys)) { + return Lists.newArrayList(); + } + + // Just delete the completed or problematic moves + if (!toDeleteKeys.isEmpty()) { + movesInProgress.get().invalidateAll(toDeleteKeys); + movesInProgressList = movesInProgressList.stream() + .filter(m -> !toDeleteKeys.contains(m.tabletId)).collect(Collectors.toList()); + } + + if (movesInProgressCache.size() > Config.max_balancing_tablets) { + LOG.debug("Total in-progress moves > {}", Config.max_balancing_tablets); + return Lists.newArrayList(); + } + + NavigableSet<Long> skews = clusterBalanceInfo.partitionInfoBySkew.keySet(); + LOG.debug("Cluster {}-{}: peek max skew {}, assume {} in-progress moves are succeeded {}", clusterName, medium, + skews.isEmpty() ? 0 : skews.last(), movesInProgressList.size(), movesInProgressList); + + List<TwoDimensionalGreedyAlgo.PartitionReplicaMove> moves = algo.getNextMoves(clusterBalanceInfo, Config.rebalance_max_moves_num_per_selection); + + List<TabletSchedCtx> alternativeTablets = Lists.newArrayList(); + List<Long> inProgressIds = movesInProgressList.stream().map(m -> m.tabletId).collect(Collectors.toList()); + for (TwoDimensionalGreedyAlgo.PartitionReplicaMove move : moves) { + // Find all tablets of the specified partition that would have a replica at the source be, + // but would not have a replica at the destination be. That is to satisfy the restriction + // of having no more than one replica of the same tablet per be. + List<Long> tabletIds = invertedIndex.getTabletIdsByBackendIdAndStorageMedium(move.fromBe, medium); + List<Long> invalidIds = invertedIndex.getTabletIdsByBackendIdAndStorageMedium(move.toBe, medium); + tabletIds.removeAll(invalidIds); + // In-progress tablets can't be the candidate too. + tabletIds.removeAll(inProgressIds); + + Map<Long, TabletMeta> tabletCandidates = Maps.newHashMap(); + for (long tabletId : tabletIds) { + TabletMeta tabletMeta = invertedIndex.getTabletMeta(tabletId); + if (tabletMeta != null && tabletMeta.getPartitionId() == move.partitionId + && tabletMeta.getIndexId() == move.indexId) { + tabletCandidates.put(tabletId, tabletMeta); + } + } + LOG.debug("Find {} candidates for move {}", tabletCandidates.size(), move); + if (tabletCandidates.isEmpty()) { + continue; + } + + // Random pick one candidate to create tabletSchedCtx + Random rand = new Random(); + Object[] keys = tabletCandidates.keySet().toArray(); + long pickedTabletId = (long) keys[rand.nextInt(keys.length)]; + LOG.debug("Picked tablet id for move {}: {}", move, pickedTabletId); + + TabletMeta tabletMeta = tabletCandidates.get(pickedTabletId); + TabletSchedCtx tabletCtx = new TabletSchedCtx(TabletSchedCtx.Type.BALANCE, clusterName, + tabletMeta.getDbId(), tabletMeta.getTableId(), tabletMeta.getPartitionId(), + tabletMeta.getIndexId(), pickedTabletId, System.currentTimeMillis()); + // Balance task's priority is always LOW + tabletCtx.setOrigPriority(TabletSchedCtx.Priority.LOW); + alternativeTablets.add(tabletCtx); + // Pair<Move, ToDeleteReplicaId>, ToDeleteReplicaId should be -1L before scheduled successfully + movesInProgress.get().put(pickedTabletId, new Pair<>(new ReplicaMove(pickedTabletId, move.fromBe, move.toBe), -1L)); + counterBalanceMoveCreated.incrementAndGet(); + // synchronize with movesInProgress + inProgressIds.add(pickedTabletId); + } + + if (moves.isEmpty()) { + // Balanced cluster should not print too much log messages. + LOG.debug("Cluster {}-{}: cluster is balanced.", clusterName, medium); + } else { + LOG.info("Cluster {}-{}: get {} moves, actually select {} alternative tablets to move. Tablets detail: {}", + clusterName, medium, moves.size(), alternativeTablets.size(), + alternativeTablets.stream().mapToLong(TabletSchedCtx::getTabletId).toArray()); + } + return alternativeTablets; + } + + private boolean buildClusterInfo(ClusterLoadStatistic clusterStat, TStorageMedium medium, + List<ReplicaMove> movesInProgress, ClusterBalanceInfo info, List<Long> toDeleteKeys) { + Preconditions.checkState(info.beByTotalReplicaCount.isEmpty() && info.partitionInfoBySkew.isEmpty(), ""); + + // If we wanna modify the PartitionBalanceInfo in info.beByTotalReplicaCount, deep-copy it + info.beByTotalReplicaCount.putAll(clusterStat.getBeByTotalReplicaMap(medium)); + info.partitionInfoBySkew.putAll(clusterStat.getSkewMap(medium)); + + // Skip the toDeleteKeys + List<ReplicaMove> filteredMoves = movesInProgress.stream().filter(m -> !toDeleteKeys.contains(m.tabletId)).collect(Collectors.toList()); + + for (ReplicaMove move : filteredMoves) { + TabletMeta meta = invertedIndex.getTabletMeta(move.tabletId); + if (meta == null) { + // Move's tablet is invalid, need delete it + toDeleteKeys.add(move.tabletId); + continue; + } + + TwoDimensionalGreedyAlgo.PartitionReplicaMove partitionMove = new TwoDimensionalGreedyAlgo. + PartitionReplicaMove(meta.getPartitionId(), meta.getIndexId(), move.fromBe, move.toBe); + boolean st = TwoDimensionalGreedyAlgo.applyMove(partitionMove, info.beByTotalReplicaCount, info.partitionInfoBySkew); + if (!st) { + // Can't apply this move, mark it failed, continue to apply the next. + toDeleteKeys.add(move.tabletId); + } + } + return true; + } + + private void checkMovesCompleted(List<ReplicaMove> moves, List<Long> toDeleteKeys) { + boolean move_is_complete; + for (ReplicaMove move : moves) { + move_is_complete = checkMoveCompleted(move); + // If the move was completed, remove it + if (move_is_complete) { + toDeleteKeys.add(move.tabletId); + LOG.debug("Move {} is completed. The cur dist: {}", move, + invertedIndex.getReplicasByTabletId(move.tabletId).stream().map(Replica::getBackendId).collect(Collectors.toList())); + counterBalanceMoveSucceeded.incrementAndGet(); + } + } + } + + // Move completed: fromBe doesn't have a replica and toBe has a replica + private boolean checkMoveCompleted(ReplicaMove move) { + Long tabletId = move.tabletId; + List<Long> bes = invertedIndex.getReplicasByTabletId(tabletId).stream().map(Replica::getBackendId).collect(Collectors.toList()); + return !bes.contains(move.fromBe) && bes.contains(move.toBe); + } + + @Override + protected void completeSchedCtx(TabletSchedCtx tabletCtx, Map<Long, TabletScheduler.PathSlot> backendsWorkingSlots) + throws SchedException { + MovesInProgressCache.Cell movesInProgress = movesInProgressCache.getCache(tabletCtx.getCluster(), tabletCtx.getStorageMedium()); + Preconditions.checkNotNull(movesInProgress, "clusterStat is got from statisticMap, movesInProgressMap should have the same entry"); + + try { + Pair<ReplicaMove, Long> pair = movesInProgress.get().getIfPresent(tabletCtx.getTabletId()); + Preconditions.checkNotNull(pair, "No cached move for tablet: " + tabletCtx.getTabletId()); + + ReplicaMove move = pair.first; + checkMoveValidation(move); + + // Check src replica's validation + Replica srcReplica = tabletCtx.getTablet().getReplicaByBackendId(move.fromBe); + Preconditions.checkNotNull(srcReplica); + TabletScheduler.PathSlot slot = backendsWorkingSlots.get(srcReplica.getBackendId()); + Preconditions.checkNotNull(slot, "unable to get fromBe " + srcReplica.getBackendId() + " slot"); + if (slot.takeBalanceSlot(srcReplica.getPathHash()) != -1) { + tabletCtx.setSrc(srcReplica); + } else { + throw new SchedException(SchedException.Status.SCHEDULE_FAILED, "no slot for src replica " + srcReplica + ", pathHash " + srcReplica.getPathHash()); + } + + // Choose a path in destination + ClusterLoadStatistic clusterStat = statisticMap.get(tabletCtx.getCluster()); + Preconditions.checkNotNull(clusterStat, "cluster does not exist: " + tabletCtx.getCluster()); + BackendLoadStatistic beStat = clusterStat.getBackendLoadStatistic(move.toBe); + Preconditions.checkNotNull(beStat); + slot = backendsWorkingSlots.get(move.toBe); + Preconditions.checkNotNull(slot, "unable to get slot of toBe " + move.toBe); + + List<RootPathLoadStatistic> paths = beStat.getPathStatistics(); + Set<Long> availPath = paths.stream().filter(path -> path.getStorageMedium() == tabletCtx.getStorageMedium() + && path.isFit(tabletCtx.getTabletSize(), false) == BalanceStatus.OK) + .map(RootPathLoadStatistic::getPathHash).collect(Collectors.toSet()); + long pathHash = slot.takeAnAvailBalanceSlotFrom(availPath); + if (pathHash == -1) { + throw new SchedException(SchedException.Status.SCHEDULE_FAILED, "paths has no available balance slot: " + availPath); + } else { + tabletCtx.setDest(beStat.getBeId(), pathHash); + } + + // ToDeleteReplica is the source replica + pair.second = srcReplica.getId(); + } catch (IllegalStateException | NullPointerException e) { + // Problematic move should be invalidated immediately + movesInProgress.get().invalidate(tabletCtx.getTabletId()); + throw new SchedException(SchedException.Status.UNRECOVERABLE, e.getMessage()); + } + } + + // The validation check cannot be accurate, cuz the production of moves do have ordering. + // If some moves failed, the cluster & partition skew is different to the skew when we getNextMove. + // So we can't do skew check. + // Just do some basic checks, e.g. server available. + private void checkMoveValidation(ReplicaMove move) throws IllegalStateException { + boolean fromAvailable = infoService.checkBackendAvailable(move.fromBe); + boolean toAvailable = infoService.checkBackendAvailable(move.toBe); + Preconditions.checkState(fromAvailable && toAvailable, move + "'s bes are not all available: from " + fromAvailable + ", to " + toAvailable); + // To be improved + } Review comment: Not all, just pick one tablet to generate one move. and apply the move to current balance info, it's in the algo implement. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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