Examples with SplitSource io.prestosql.split.SplitSource used on opensource projects

Example 1 with SplitSource

use of io.prestosql.split.SplitSource in project hetu-core by openlookeng.

the class DistributedExecutionPlanner method plan.

public StageExecutionPlan plan(SubPlan root, Session session, Mode mode, Long resumeSnapshotId, long nextSnapshotId) {
    ImmutableList.Builder<SplitSource> allSplitSources = ImmutableList.builder();
    try {
        if (mode != Mode.SNAPSHOT) {
            return doPlan(mode, root, session, resumeSnapshotId, nextSnapshotId, allSplitSources, null, null, null);
        }
        // Capture dependencies among table scan sources. Only need to do this for the initial planning.
        // The leftmost source of each fragment. Key is fragment id; value is SplitSource or ValuesNode or RemoteSourceNode
        Map<PlanFragmentId, Object> leftmostSources = new HashMap<>();
        // Source dependency. Key is SplitSource or ValuesNode or RemoteSourceNode; value is SplitSource or ValuesNode or RemoteSourceNode
        Multimap<Object, Object> sourceDependencies = HashMultimap.create();
        // List of sources from the same union. Values are SplitSource or ValuesNode or RemoteSourceNode.
        List<List<Object>> unionSources = new ArrayList<>();
        StageExecutionPlan ret = doPlan(mode, root, session, resumeSnapshotId, nextSnapshotId, allSplitSources, leftmostSources, sourceDependencies, unionSources);
        for (Map.Entry<Object, Object> entry : sourceDependencies.entries()) {
            List<MarkerSplitSource> right = collectSources(leftmostSources, entry.getValue());
            for (MarkerSplitSource source : collectSources(leftmostSources, entry.getKey())) {
                for (SplitSource dependency : right) {
                    source.addDependency((MarkerSplitSource) dependency);
                }
            }
        }
        List<MarkerSplitSource> sources = new ArrayList<>();
        for (List<Object> union : unionSources) {
            sources.clear();
            for (Object unionSource : union) {
                sources.addAll(collectSources(leftmostSources, unionSource));
            }
            // Adding all these sources as "union dependencies" for each other, to make sure they produce the same set of markers.
            for (MarkerSplitSource source : sources) {
                source.addUnionSources(sources);
            }
        }
        return ret;
    } catch (Throwable t) {
        allSplitSources.build().forEach(DistributedExecutionPlanner::closeSplitSource);
        throw t;
    }
}

Example 2 with SplitSource

use of io.prestosql.split.SplitSource in project hetu-core by openlookeng.

the class TestSourcePartitionedScheduler method getSourcePartitionedScheduler.

private static StageScheduler getSourcePartitionedScheduler(StageExecutionPlan plan, SqlStageExecution stage, InternalNodeManager nodeManager, NodeTaskMap nodeTaskMap, int splitBatchSize) {
    NodeSchedulerConfig nodeSchedulerConfig = new NodeSchedulerConfig().setIncludeCoordinator(false).setMaxSplitsPerNode(20).setMaxPendingSplitsPerTask(0);
    NodeScheduler nodeScheduler = new NodeScheduler(new LegacyNetworkTopology(), nodeManager, nodeSchedulerConfig, nodeTaskMap);
    PlanNodeId sourceNode = Iterables.getOnlyElement(plan.getSplitSources().keySet());
    SplitSource splitSource = Iterables.getOnlyElement(plan.getSplitSources().values());
    SplitPlacementPolicy placementPolicy = new DynamicSplitPlacementPolicy(nodeScheduler.createNodeSelector(splitSource.getCatalogName(), false, null), stage::getAllTasks);
    return newSourcePartitionedSchedulerAsStageScheduler(stage, sourceNode, splitSource, placementPolicy, splitBatchSize, session, new HeuristicIndexerManager(new FileSystemClientManager(), new HetuMetaStoreManager()));
}

Example 3 with SplitSource

use of io.prestosql.split.SplitSource in project hetu-core by openlookeng.

the class ExtractSpatialJoins method loadKdbTree.

private static KdbTree loadKdbTree(String tableName, Session session, Metadata metadata, SplitManager splitManager, PageSourceManager pageSourceManager, PlanNodeId nodeId) {
    QualifiedObjectName name = toQualifiedObjectName(tableName, session.getCatalog().get(), session.getSchema().get());
    TableHandle tableHandle = metadata.getTableHandle(session, name).orElseThrow(() -> new PrestoException(INVALID_SPATIAL_PARTITIONING, format("Table not found: %s", name)));
    Map<String, ColumnHandle> columnHandles = metadata.getColumnHandles(session, tableHandle);
    List<ColumnHandle> visibleColumnHandles = columnHandles.values().stream().filter(handle -> !metadata.getColumnMetadata(session, tableHandle, handle).isHidden()).collect(toImmutableList());
    checkSpatialPartitioningTable(visibleColumnHandles.size() == 1, "Expected single column for table %s, but found %s columns", name, columnHandles.size());
    ColumnHandle kdbTreeColumn = Iterables.getOnlyElement(visibleColumnHandles);
    Optional<KdbTree> kdbTree = Optional.empty();
    try (SplitSource splitSource = splitManager.getSplits(session, tableHandle, UNGROUPED_SCHEDULING, null, Optional.empty(), Collections.emptyMap(), ImmutableSet.of(), false, nodeId)) {
        while (!Thread.currentThread().isInterrupted()) {
            SplitBatch splitBatch = getFutureValue(splitSource.getNextBatch(NOT_PARTITIONED, Lifespan.taskWide(), 1000));
            List<Split> splits = splitBatch.getSplits();
            for (Split split : splits) {
                try (ConnectorPageSource pageSource = pageSourceManager.createPageSource(session, split, tableHandle, ImmutableList.of(kdbTreeColumn), Optional.empty())) {
                    do {
                        getFutureValue(pageSource.isBlocked());
                        Page page = pageSource.getNextPage();
                        if (page != null && page.getPositionCount() > 0) {
                            checkSpatialPartitioningTable(!kdbTree.isPresent(), "Expected exactly one row for table %s, but found more", name);
                            checkSpatialPartitioningTable(page.getPositionCount() == 1, "Expected exactly one row for table %s, but found %s rows", name, page.getPositionCount());
                            String kdbTreeJson = VARCHAR.getSlice(page.getBlock(0), 0).toStringUtf8();
                            try {
                                kdbTree = Optional.of(KdbTreeUtils.fromJson(kdbTreeJson));
                            } catch (IllegalArgumentException e) {
                                checkSpatialPartitioningTable(false, "Invalid JSON string for KDB tree: %s", e.getMessage());
                            }
                        }
                    } while (!pageSource.isFinished());
                } catch (IOException e) {
                    throw new UncheckedIOException(e);
                }
            }
            if (splitBatch.isLastBatch()) {
                break;
            }
        }
    }
    checkSpatialPartitioningTable(kdbTree.isPresent(), "Expected exactly one row for table %s, but got none", name);
    return kdbTree.get();
}

Example 4 with SplitSource

use of io.prestosql.split.SplitSource in project hetu-core by openlookeng.

the class SqlQueryScheduler method createStages.

private List<SqlStageExecution> createStages(ExchangeLocationsConsumer parent, AtomicInteger nextStageId, LocationFactory locationFactory, StageExecutionPlan plan, NodeScheduler nodeScheduler, RemoteTaskFactory remoteTaskFactory, Session session, int splitBatchSize, BiFunction<PartitioningHandle, Integer, NodePartitionMap> partitioningCache, NodePartitioningManager nodePartitioningManager, ExecutorService queryExecutor, ScheduledExecutorService schedulerExecutor, FailureDetector failureDetector, NodeTaskMap nodeTaskMap, ImmutableMap.Builder<StageId, StageScheduler> stageSchedulers, ImmutableMap.Builder<StageId, StageLinkage> stageLinkages, boolean isSnapshotEnabled, QuerySnapshotManager snapshotManager, Map<StageId, Integer> stageTaskCounts) {
    ImmutableList.Builder<SqlStageExecution> localStages = ImmutableList.builder();
    StageId stageId = new StageId(queryStateMachine.getQueryId(), nextStageId.getAndIncrement());
    SqlStageExecution stageExecution = createSqlStageExecution(stageId, locationFactory.createStageLocation(stageId), plan.getFragment(), plan.getTables(), remoteTaskFactory, session, summarizeTaskInfo, nodeTaskMap, queryExecutor, failureDetector, schedulerStats, dynamicFilterService, snapshotManager);
    localStages.add(stageExecution);
    Optional<int[]> bucketToPartition;
    PartitioningHandle partitioningHandle = plan.getFragment().getPartitioning();
    boolean keepConsumerOnFeederNodes = !plan.getFragment().getFeederCTEId().isPresent() && plan.getFragment().getFeederCTEParentId().isPresent();
    if (partitioningHandle.equals(SOURCE_DISTRIBUTION)) {
        // nodes are selected dynamically based on the constraints of the splits and the system load
        Entry<PlanNodeId, SplitSource> entry = Iterables.getOnlyElement(plan.getSplitSources().entrySet());
        PlanNodeId planNodeId = entry.getKey();
        SplitSource splitSource = entry.getValue();
        CatalogName catalogName = splitSource.getCatalogName();
        if (isInternalSystemConnector(catalogName)) {
            catalogName = null;
        }
        NodeSelector nodeSelector = nodeScheduler.createNodeSelector(catalogName, keepConsumerOnFeederNodes, feederScheduledNodes);
        if (isSnapshotEnabled) {
            // When snapshot is enabled, then no task can be added after the query started running,
            // otherwise assumptions about how many "input channels" may be broken.
            nodeSelector.lockDownNodes();
        }
        SplitPlacementPolicy placementPolicy = new DynamicSplitPlacementPolicy(nodeSelector, stageExecution::getAllTasks);
        checkArgument(!plan.getFragment().getStageExecutionDescriptor().isStageGroupedExecution());
        stageSchedulers.put(stageId, newSourcePartitionedSchedulerAsStageScheduler(stageExecution, planNodeId, splitSource, placementPolicy, splitBatchSize, session, heuristicIndexerManager));
        bucketToPartition = Optional.of(new int[1]);
    } else if (partitioningHandle.equals(SCALED_WRITER_DISTRIBUTION)) {
        bucketToPartition = Optional.of(new int[1]);
    } else {
        Map<PlanNodeId, SplitSource> splitSources = plan.getSplitSources();
        if (!splitSources.isEmpty()) {
            // contains local source
            List<PlanNodeId> schedulingOrder = plan.getFragment().getPartitionedSources();
            CatalogName catalogName = partitioningHandle.getConnectorId().orElseThrow(IllegalStateException::new);
            List<ConnectorPartitionHandle> connectorPartitionHandles;
            boolean groupedExecutionForStage = plan.getFragment().getStageExecutionDescriptor().isStageGroupedExecution();
            if (groupedExecutionForStage) {
                connectorPartitionHandles = nodePartitioningManager.listPartitionHandles(session, partitioningHandle);
                checkState(!ImmutableList.of(NOT_PARTITIONED).equals(connectorPartitionHandles));
            } else {
                connectorPartitionHandles = ImmutableList.of(NOT_PARTITIONED);
            }
            BucketNodeMap bucketNodeMap;
            List<InternalNode> stageNodeList;
            if (plan.getFragment().getRemoteSourceNodes().stream().allMatch(node -> node.getExchangeType() == REPLICATE)) {
                // no remote source
                boolean dynamicLifespanSchedule = plan.getFragment().getStageExecutionDescriptor().isDynamicLifespanSchedule();
                if (isSnapshotEnabled) {
                    NodeSelector nodeSelector = nodeScheduler.createNodeSelector(catalogName, keepConsumerOnFeederNodes, feederScheduledNodes);
                    int nodeCount;
                    if (stageTaskCounts != null) {
                        // Resuming: need to create same number of tasks as old stage.
                        nodeCount = stageTaskCounts.get(stageId);
                    } else {
                        // Scheduling: reserve some nodes for resuming
                        nodeCount = calculateTaskCount(nodeSelector.selectableNodeCount());
                    }
                    stageNodeList = new ArrayList<>(nodeSelector.selectRandomNodes(nodeCount));
                    checkCondition(stageNodeList.size() == nodeCount, NO_NODES_AVAILABLE, "Snapshot: not enough worker nodes to resume expected number of tasks: " + nodeCount);
                    // Make sure bucketNodeMap uses the same node list
                    bucketNodeMap = nodePartitioningManager.getBucketNodeMap(session, partitioningHandle, dynamicLifespanSchedule, stageNodeList);
                } else {
                    bucketNodeMap = nodePartitioningManager.getBucketNodeMap(session, partitioningHandle, dynamicLifespanSchedule);
                    stageNodeList = new ArrayList<>(nodeScheduler.createNodeSelector(catalogName, keepConsumerOnFeederNodes, feederScheduledNodes).allNodes());
                }
                // verify execution is consistent with planner's decision on dynamic lifespan schedule
                verify(bucketNodeMap.isDynamic() == dynamicLifespanSchedule);
                Collections.shuffle(stageNodeList);
                bucketToPartition = Optional.empty();
            } else {
                // cannot use dynamic lifespan schedule
                verify(!plan.getFragment().getStageExecutionDescriptor().isDynamicLifespanSchedule());
                // remote source requires nodePartitionMap
                NodePartitionMap nodePartitionMap = partitioningCache.apply(plan.getFragment().getPartitioning(), stageTaskCounts == null ? null : stageTaskCounts.get(stageId));
                if (groupedExecutionForStage) {
                    checkState(connectorPartitionHandles.size() == nodePartitionMap.getBucketToPartition().length);
                }
                stageNodeList = nodePartitionMap.getPartitionToNode();
                bucketNodeMap = nodePartitionMap.asBucketNodeMap();
                bucketToPartition = Optional.of(nodePartitionMap.getBucketToPartition());
            }
            stageSchedulers.put(stageId, new FixedSourcePartitionedScheduler(stageExecution, splitSources, plan.getFragment().getStageExecutionDescriptor(), schedulingOrder, stageNodeList, bucketNodeMap, splitBatchSize, getConcurrentLifespansPerNode(session), nodeScheduler.createNodeSelector(catalogName, keepConsumerOnFeederNodes, feederScheduledNodes), connectorPartitionHandles, session, heuristicIndexerManager));
        } else {
            // all sources are remote
            NodePartitionMap nodePartitionMap = partitioningCache.apply(plan.getFragment().getPartitioning(), stageTaskCounts == null ? null : stageTaskCounts.get(stageId));
            List<InternalNode> partitionToNode = nodePartitionMap.getPartitionToNode();
            // todo this should asynchronously wait a standard timeout period before failing
            checkCondition(!partitionToNode.isEmpty(), NO_NODES_AVAILABLE, "No worker nodes available");
            stageSchedulers.put(stageId, new FixedCountScheduler(stageExecution, partitionToNode));
            bucketToPartition = Optional.of(nodePartitionMap.getBucketToPartition());
        }
    }
    ImmutableSet.Builder<SqlStageExecution> childStagesBuilder = ImmutableSet.builder();
    for (StageExecutionPlan subStagePlan : plan.getSubStages()) {
        if (visitedPlanFrags.contains(subStagePlan.getFragment().getId())) {
            continue;
        }
        visitedPlanFrags.add(subStagePlan.getFragment().getId());
        List<SqlStageExecution> subTree = createStages(stageExecution::addExchangeLocations, nextStageId, locationFactory, subStagePlan.withBucketToPartition(bucketToPartition), nodeScheduler, remoteTaskFactory, session, splitBatchSize, partitioningCache, nodePartitioningManager, queryExecutor, schedulerExecutor, failureDetector, nodeTaskMap, stageSchedulers, stageLinkages, isSnapshotEnabled, snapshotManager, stageTaskCounts);
        localStages.addAll(subTree);
        SqlStageExecution childStage = subTree.get(0);
        childStagesBuilder.add(childStage);
        Optional<RemoteSourceNode> parentNode = plan.getFragment().getRemoteSourceNodes().stream().filter(x -> x.getSourceFragmentIds().contains(childStage.getFragment().getId())).findAny();
        checkArgument(parentNode.isPresent(), "Couldn't find parent of a CTE node");
        childStage.setParentId(parentNode.get().getId());
    }
    Set<SqlStageExecution> childStages = childStagesBuilder.build();
    stageExecution.addStateChangeListener(newState -> {
        if (newState.isDone() && newState != StageState.RESCHEDULING) {
            // Snapshot: For "rescheduling", tasks are already cancelled (for resume)
            childStages.forEach(SqlStageExecution::cancel);
        }
    });
    stageLinkages.put(stageId, new StageLinkage(plan.getFragment().getId(), parent, childStages));
    if (partitioningHandle.equals(SCALED_WRITER_DISTRIBUTION)) {
        Supplier<Collection<TaskStatus>> sourceTasksProvider = () -> childStages.stream().map(SqlStageExecution::getAllTasks).flatMap(Collection::stream).map(RemoteTask::getTaskStatus).collect(toList());
        Supplier<Collection<TaskStatus>> writerTasksProvider = () -> stageExecution.getAllTasks().stream().map(RemoteTask::getTaskStatus).collect(toList());
        ScaledWriterScheduler scheduler = new ScaledWriterScheduler(stageExecution, sourceTasksProvider, writerTasksProvider, nodeScheduler.createNodeSelector(null, keepConsumerOnFeederNodes, feederScheduledNodes), schedulerExecutor, getWriterMinSize(session), isSnapshotEnabled, stageTaskCounts != null ? stageTaskCounts.get(stageId) : null);
        whenAllStages(childStages, StageState::isDone).addListener(scheduler::finish, directExecutor());
        stageSchedulers.put(stageId, scheduler);
    }
    return localStages.build();
}

Example 5 with SplitSource

use of io.prestosql.split.SplitSource in project hetu-core by openlookeng.

the class SourcePartitionedScheduler method schedule.

@Override
public synchronized ScheduleResult schedule(int maxSplitGroup) {
    dropListenersFromWhenFinishedOrNewLifespansAdded();
    int overallSplitAssignmentCount = 0;
    ImmutableSet.Builder<RemoteTask> overallNewTasks = ImmutableSet.builder();
    List<ListenableFuture<?>> overallBlockedFutures = new ArrayList<>();
    boolean anyBlockedOnPlacements = false;
    boolean anyBlockedOnNextSplitBatch = false;
    boolean anyNotBlocked = false;
    boolean applyFilter = isHeuristicIndexFilterEnabled(session) && SplitFiltering.isSplitFilterApplicable(stage);
    boolean initialMarker = false;
    for (Entry<Lifespan, ScheduleGroup> entry : scheduleGroups.entrySet()) {
        Lifespan lifespan = entry.getKey();
        ScheduleGroup scheduleGroup = entry.getValue();
        Set<Split> pendingSplits = scheduleGroup.pendingSplits;
        if (scheduleGroup.state == ScheduleGroupState.NO_MORE_SPLITS || scheduleGroup.state == ScheduleGroupState.DONE) {
            verify(scheduleGroup.nextSplitBatchFuture == null);
        } else if (pendingSplits.isEmpty()) {
            // try to get the next batch
            if (scheduleGroup.nextSplitBatchFuture == null) {
                scheduleGroup.nextSplitBatchFuture = splitSource.getNextBatch(scheduleGroup.partitionHandle, lifespan, splitBatchSize - pendingSplits.size());
                long start = System.nanoTime();
                addSuccessCallback(scheduleGroup.nextSplitBatchFuture, () -> stage.recordGetSplitTime(start));
            }
            if (scheduleGroup.nextSplitBatchFuture.isDone()) {
                SplitBatch nextSplits = getFutureValue(scheduleGroup.nextSplitBatchFuture);
                scheduleGroup.nextSplitBatchFuture = null;
                // add split filter to filter out split has no valid rows
                Pair<Optional<RowExpression>, Map<Symbol, ColumnHandle>> pair = SplitFiltering.getExpression(stage);
                if (SystemSessionProperties.isSnapshotEnabled(session)) {
                    List<Split> batchSplits = nextSplits.getSplits();
                    // Don't apply filter to MarkerSplit
                    if (batchSplits.size() == 1 && batchSplits.get(0).getConnectorSplit() instanceof MarkerSplit) {
                        applyFilter = false;
                    }
                }
                List<Split> filteredSplit = applyFilter ? SplitFiltering.getFilteredSplit(pair.getFirst(), SplitFiltering.getFullyQualifiedName(stage), pair.getSecond(), nextSplits, heuristicIndexerManager) : nextSplits.getSplits();
                // In case of ORC small size files/splits are grouped
                List<Split> groupedSmallFilesList = splitSource.groupSmallSplits(filteredSplit, lifespan, maxSplitGroup);
                filteredSplit = groupedSmallFilesList;
                pendingSplits.addAll(filteredSplit);
                if (nextSplits.isLastBatch()) {
                    if (scheduleGroup.state == ScheduleGroupState.INITIALIZED && pendingSplits.isEmpty()) {
                        // Add an empty split in case no splits have been produced for the source.
                        // For source operators, they never take input, but they may produce output.
                        // This is well handled by Presto execution engine.
                        // However, there are certain non-source operators that may produce output without any input,
                        // for example, 1) an AggregationOperator, 2) a HashAggregationOperator where one of the grouping sets is ().
                        // Scheduling an empty split kicks off necessary driver instantiation to make this work.
                        pendingSplits.add(new Split(splitSource.getCatalogName(), new EmptySplit(splitSource.getCatalogName()), lifespan));
                    }
                    scheduleGroup.state = ScheduleGroupState.NO_MORE_SPLITS;
                }
            } else {
                overallBlockedFutures.add(scheduleGroup.nextSplitBatchFuture);
                anyBlockedOnNextSplitBatch = true;
                continue;
            }
        }
        Multimap<InternalNode, Split> splitAssignment = ImmutableMultimap.of();
        if (!pendingSplits.isEmpty()) {
            if (!scheduleGroup.placementFuture.isDone()) {
                anyBlockedOnPlacements = true;
                continue;
            }
            if (scheduleGroup.state == ScheduleGroupState.INITIALIZED) {
                scheduleGroup.state = ScheduleGroupState.SPLITS_ADDED;
            }
            if (state == State.INITIALIZED) {
                state = State.SPLITS_ADDED;
            }
            // calculate placements for splits
            SplitPlacementResult splitPlacementResult;
            if (stage.isThrottledSchedule()) {
                // If asked for partial schedule incase of lesser resource, then schedule only 10% of splits.
                // 10% is calculated on initial number of splits and same is being used on subsequent schedule also.
                // But if later 10% of current pending splits more than earlier 10%, then it will schedule max of
                // these.
                // if throttledSplitsCount is more than number of pendingSplits, then it will schedule all.
                throttledSplitsCount = Math.max((int) Math.ceil(pendingSplits.size() * ALLOWED_PERCENT_LIMIT), throttledSplitsCount);
                splitPlacementResult = splitPlacementPolicy.computeAssignments(ImmutableSet.copyOf(Iterables.limit(pendingSplits, throttledSplitsCount)), this.stage);
            } else {
                splitPlacementResult = splitPlacementPolicy.computeAssignments(new HashSet<>(pendingSplits), this.stage);
            }
            splitAssignment = splitPlacementResult.getAssignments();
            if (SystemSessionProperties.isSnapshotEnabled(session)) {
                Split firstSplit = pendingSplits.iterator().next();
                if (pendingSplits.size() == 1 && firstSplit.getConnectorSplit() instanceof MarkerSplit) {
                    // We'll create a new assignment, but still need to call computeAssignments above, and cannot modify the returned assignment map directly
                    splitAssignment = HashMultimap.create(splitAssignment);
                    splitAssignment.values().remove(firstSplit);
                    // Getting all internalNodes and assigning marker splits to all of them.
                    List<InternalNode> allNodes = splitPlacementPolicy.allNodes();
                    for (InternalNode node : allNodes) {
                        splitAssignment.put(node, firstSplit);
                    }
                    MarkerSplit markerSplit = (MarkerSplit) firstSplit.getConnectorSplit();
                    // then set the flag below to true, so stages enter SCHEDULING_SPLITS state.
                    if (markerSplit.isResuming() || markerSplit.getSnapshotId() == 0) {
                        initialMarker = true;
                    }
                } else {
                    // MarkerSplit should be in its own batch.
                    verify(pendingSplits.stream().noneMatch(split -> split.getConnectorSplit() instanceof MarkerSplit));
                }
            }
            // remove splits with successful placements
            // AbstractSet.removeAll performs terribly here.
            splitAssignment.values().forEach(pendingSplits::remove);
            overallSplitAssignmentCount += splitAssignment.size();
            // if not completed placed, mark scheduleGroup as blocked on placement
            if (!pendingSplits.isEmpty()) {
                scheduleGroup.placementFuture = splitPlacementResult.getBlocked();
                overallBlockedFutures.add(scheduleGroup.placementFuture);
                anyBlockedOnPlacements = true;
            }
        }
        // if no new splits will be assigned, update state and attach completion event
        Multimap<InternalNode, Lifespan> noMoreSplitsNotification = ImmutableMultimap.of();
        if (pendingSplits.isEmpty() && scheduleGroup.state == ScheduleGroupState.NO_MORE_SPLITS) {
            scheduleGroup.state = ScheduleGroupState.DONE;
            if (!lifespan.isTaskWide()) {
                InternalNode node = ((BucketedSplitPlacementPolicy) splitPlacementPolicy).getNodeForBucket(lifespan.getId());
                noMoreSplitsNotification = ImmutableMultimap.of(node, lifespan);
            }
        }
        // assign the splits with successful placements
        overallNewTasks.addAll(assignSplits(splitAssignment, noMoreSplitsNotification));
        // As a result, to avoid busy loops caused by 1, we check pendingSplits.isEmpty() instead of placementFuture.isDone() here.
        if (scheduleGroup.nextSplitBatchFuture == null && scheduleGroup.pendingSplits.isEmpty() && scheduleGroup.state != ScheduleGroupState.DONE) {
            anyNotBlocked = true;
        }
    }
    // Next time it invokes getNextBatch, it will realize that. However, the invocation will fail we tear down splitSource now.
    if ((state == State.NO_MORE_SPLITS || state == State.FINISHED) || (noMoreScheduleGroups && scheduleGroups.isEmpty() && splitSource.isFinished())) {
        switch(state) {
            case INITIALIZED:
                // But this shouldn't be possible. See usage of EmptySplit in this method.
                throw new IllegalStateException("At least 1 split should have been scheduled for this plan node");
            case SPLITS_ADDED:
                state = State.NO_MORE_SPLITS;
                splitSource.close();
            // fall through
            case NO_MORE_SPLITS:
                state = State.FINISHED;
                whenFinishedOrNewLifespanAdded.set(null);
            // fall through
            case FINISHED:
                return new ScheduleResult(true, overallNewTasks.build(), overallSplitAssignmentCount);
            default:
                throw new IllegalStateException("Unknown state");
        }
    }
    if (anyNotBlocked) {
        if (initialMarker) {
            stage.transitionToSchedulingSplits();
        }
        return new ScheduleResult(false, overallNewTasks.build(), overallSplitAssignmentCount);
    }
    if (anyBlockedOnPlacements || groupedExecution) {
        // In a broadcast join, output buffers of the tasks in build source stage have to
        // hold onto all data produced before probe side task scheduling finishes,
        // even if the data is acknowledged by all known consumers. This is because
        // new consumers may be added until the probe side task scheduling finishes.
        // 
        // As a result, the following line is necessary to prevent deadlock
        // due to neither build nor probe can make any progress.
        // The build side blocks due to a full output buffer.
        // In the meantime the probe side split cannot be consumed since
        // builder side hash table construction has not finished.
        overallNewTasks.addAll(finalizeTaskCreationIfNecessary());
    }
    ScheduleResult.BlockedReason blockedReason;
    if (anyBlockedOnNextSplitBatch) {
        blockedReason = anyBlockedOnPlacements ? MIXED_SPLIT_QUEUES_FULL_AND_WAITING_FOR_SOURCE : WAITING_FOR_SOURCE;
    } else {
        blockedReason = anyBlockedOnPlacements ? SPLIT_QUEUES_FULL : NO_ACTIVE_DRIVER_GROUP;
    }
    overallBlockedFutures.add(whenFinishedOrNewLifespanAdded);
    return new ScheduleResult(false, overallNewTasks.build(), nonCancellationPropagating(whenAnyComplete(overallBlockedFutures)), blockedReason, overallSplitAssignmentCount);
}